[systemd-commits] 2 commits - configure.ac .gitignore Makefile.am src/libsystemd-terminal src/nspawn

David Herrmann dvdhrm at kemper.freedesktop.org
Thu Jul 17 02:49:08 PDT 2014


 .gitignore                               |    1 
 Makefile.am                              |   28 
 configure.ac                             |   10 
 src/libsystemd-terminal/term-internal.h  |  253 ++++++
 src/libsystemd-terminal/term-page.c      | 1142 +++++++++++++++++++++++++++++++
 src/libsystemd-terminal/term-wcwidth.c   |  313 ++++++++
 src/libsystemd-terminal/test-term-page.c |  463 ++++++++++++
 src/nspawn/nspawn.c                      |    2 
 8 files changed, 2211 insertions(+), 1 deletion(-)

New commits:
commit 84da4a3022bc599b26d9601cf1b7bf51d1d9f915
Author: David Herrmann <dh.herrmann at gmail.com>
Date:   Thu Jun 12 17:51:14 2014 +0200

    ui/term: add line/cell/char handling for terminal pages
    
    This commit introduces libsystemd-ui, a systemd-internal helper library
    that will contain all the UI related functionality. It is going to be used
    by systemd-welcomed, systemd-consoled, systemd-greeter and systemd-er.
    Further use-cases may follow.
    
    For now, this commit only adds terminal-page handling based on lines only.
    Follow-up commits will add more functionality.

diff --git a/.gitignore b/.gitignore
index aecc6ae..0ba01da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -219,6 +219,7 @@
 /test-strv
 /test-strxcpyx
 /test-tables
+/test-term-page
 /test-time
 /test-tmpfiles
 /test-udev
diff --git a/Makefile.am b/Makefile.am
index a9ee8b0..0b9491a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -209,6 +209,7 @@ AM_CPPFLAGS = \
 	-I $(top_srcdir)/src/libsystemd/sd-event \
 	-I $(top_srcdir)/src/libsystemd/sd-rtnl \
 	-I $(top_srcdir)/src/libsystemd-network \
+	-I $(top_srcdir)/src/libsystemd-terminal \
 	$(OUR_CPPFLAGS)
 
 AM_CFLAGS = $(OUR_CFLAGS)
@@ -2827,6 +2828,33 @@ tests += \
 	test-dhcp6-client
 
 # ------------------------------------------------------------------------------
+noinst_LTLIBRARIES += \
+	libsystemd-terminal.la
+
+libsystemd_terminal_la_CFLAGS = \
+	$(AM_CFLAGS)
+
+libsystemd_terminal_la_SOURCES = \
+	src/libsystemd-terminal/term-internal.h \
+	src/libsystemd-terminal/term-page.c \
+	src/libsystemd-terminal/term-wcwidth.c
+
+libsystemd_terminal_la_LIBADD = \
+	libsystemd-internal.la \
+	libsystemd-shared.la
+
+test_term_page_SOURCES = \
+	src/libsystemd-terminal/test-term-page.c
+
+test_term_page_LDADD = \
+	libsystemd-terminal.la \
+	libsystemd-internal.la \
+	libsystemd-shared.la
+
+tests += \
+	test-term-page
+
+# ------------------------------------------------------------------------------
 if ENABLE_GTK_DOC
 SUBDIRS += \
 	docs/libudev
diff --git a/configure.ac b/configure.ac
index be05211..6f888a2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1044,6 +1044,15 @@ fi
 AM_CONDITIONAL(ENABLE_MULTI_SEAT_X, [test "$have_multi_seat_x" = "yes"])
 
 # ------------------------------------------------------------------------------
+have_terminal=no
+AC_ARG_ENABLE(terminal, AS_HELP_STRING([--enable-terminal], [enable terminal support]))
+if test "x$enable_terminal" = "xyes"; then
+        AC_DEFINE(ENABLE_TERMINAL, 1, [Define if terminal support is to be enabled])
+        have_terminal=yes
+fi
+AM_CONDITIONAL(ENABLE_TERMINAL, [test "x$have_terminal" = "xyes"])
+
+# ------------------------------------------------------------------------------
 have_kdbus=no
 AC_ARG_ENABLE(kdbus, AS_HELP_STRING([--enable-kdbus], [do connect to kdbus by default]))
 if test "x$enable_kdbus" = "xyes"; then
@@ -1348,6 +1357,7 @@ AC_MSG_RESULT([
         gudev:                   ${enable_gudev}
         gintrospection:          ${enable_introspection}
         multi-seat-x:            ${have_multi_seat_x}
+        terminal:                ${have_terminal}
         kdbus:                   ${have_kdbus}
         Python:                  ${have_python}
         Python Headers:          ${have_python_devel}
diff --git a/src/libsystemd-terminal/term-internal.h b/src/libsystemd-terminal/term-internal.h
new file mode 100644
index 0000000..af1c723
--- /dev/null
+++ b/src/libsystemd-terminal/term-internal.h
@@ -0,0 +1,253 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 David Herrmann <dh.herrmann at gmail.com>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include "util.h"
+
+typedef struct term_char term_char_t;
+typedef struct term_charbuf term_charbuf_t;
+
+typedef struct term_color term_color;
+typedef struct term_attr term_attr;
+typedef struct term_cell term_cell;
+typedef struct term_line term_line;
+
+/*
+ * Miscellaneous
+ * Sundry things and external helpers.
+ */
+
+int mk_wcwidth(wchar_t ucs4);
+int mk_wcwidth_cjk(wchar_t ucs4);
+int mk_wcswidth(const wchar_t *str, size_t len);
+int mk_wcswidth_cjk(const wchar_t *str, size_t len);
+
+/*
+ * Ageing
+ * Redrawing terminals is quite expensive. Therefore, we avoid redrawing on
+ * each single modification and mark modified cells instead. This way, we know
+ * which cells to redraw on the next frame. However, a single DIRTY flag is not
+ * enough for double/triple buffered screens, hence, we use an AGE field for
+ * each cell. If the cell is modified, we simply increase the age by one. Each
+ * framebuffer can then remember its last rendered age and request an update of
+ * all newer cells.
+ * TERM_AGE_NULL is special. If used as cell age, the cell must always be
+ * redrawn (forced update). If used as framebuffer age, all cells are drawn.
+ * This way, we can allow integer wrap-arounds.
+ */
+
+typedef uint64_t term_age_t;
+
+#define TERM_AGE_NULL 0
+
+/*
+ * Characters
+ * Each cell in a terminal page contains only a single character. This is
+ * usually a single UCS-4 value. However, Unicode allows combining-characters,
+ * therefore, the number of UCS-4 characters per cell must be unlimited. The
+ * term_char_t object wraps the internal combining char API so it can be
+ * treated as a single object.
+ */
+
+struct term_char {
+        /* never access this value directly */
+        uint64_t _value;
+};
+
+struct term_charbuf {
+        /* 3 bytes + zero-terminator */
+        uint32_t buf[4];
+};
+
+#define TERM_CHAR_INIT(_val) ((term_char_t){ ._value = (_val) })
+#define TERM_CHAR_NULL TERM_CHAR_INIT(0)
+
+term_char_t term_char_set(term_char_t previous, uint32_t append_ucs4);
+term_char_t term_char_merge(term_char_t base, uint32_t append_ucs4);
+term_char_t term_char_dup(term_char_t ch);
+term_char_t term_char_dup_append(term_char_t base, uint32_t append_ucs4);
+
+const uint32_t *term_char_resolve(term_char_t ch, size_t *s, term_charbuf_t *b);
+unsigned int term_char_lookup_width(term_char_t ch);
+
+/* true if @ch is TERM_CHAR_NULL, otherwise false */
+static inline bool term_char_is_null(term_char_t ch) {
+        return ch._value == 0;
+}
+
+/* true if @ch is dynamically allocated and needs to be freed */
+static inline bool term_char_is_allocated(term_char_t ch) {
+        return !term_char_is_null(ch) && !(ch._value & 0x1);
+}
+
+/* true if (a == b), otherwise false; this is (a == b), NOT (*a == *b) */
+static inline bool term_char_same(term_char_t a, term_char_t b) {
+        return a._value == b._value;
+}
+
+/* true if (*a == *b), otherwise false; this is implied by (a == b) */
+static inline bool term_char_equal(term_char_t a, term_char_t b) {
+        const uint32_t *sa, *sb;
+        term_charbuf_t ca, cb;
+        size_t na, nb;
+
+        sa = term_char_resolve(a, &na, &ca);
+        sb = term_char_resolve(b, &nb, &cb);
+        return na == nb && !memcmp(sa, sb, sizeof(*sa) * na);
+}
+
+/* free @ch in case it is dynamically allocated */
+static inline term_char_t term_char_free(term_char_t ch) {
+        if (term_char_is_allocated(ch))
+                term_char_set(ch, 0);
+
+        return TERM_CHAR_NULL;
+}
+
+/* gcc _cleanup_ helpers */
+#define _term_char_free_ _cleanup_(term_char_freep)
+static inline void term_char_freep(term_char_t *p) {
+        term_char_free(*p);
+}
+
+/*
+ * Attributes
+ * Each cell in a terminal page can have its own set of attributes. These alter
+ * the behavior of the renderer for this single cell. We use term_attr to
+ * specify attributes.
+ * The only non-obvious field is "ccode" for foreground and background colors.
+ * This field contains the terminal color-code in case no full RGB information
+ * was given by the host. It is also required for dynamic color palettes. If it
+ * is set to TERM_CCODE_RGB, the "red", "green" and "blue" fields contain the
+ * full RGB color.
+ */
+
+enum {
+        /* dark color-codes */
+        TERM_CCODE_BLACK,
+        TERM_CCODE_RED,
+        TERM_CCODE_GREEN,
+        TERM_CCODE_YELLOW,
+        TERM_CCODE_BLUE,
+        TERM_CCODE_MAGENTA,
+        TERM_CCODE_CYAN,
+        TERM_CCODE_WHITE,                                               /* technically: light grey */
+
+        /* light color-codes */
+        TERM_CCODE_LIGHT_BLACK          = TERM_CCODE_BLACK + 8,         /* technically: dark grey */
+        TERM_CCODE_LIGHT_RED            = TERM_CCODE_RED + 8,
+        TERM_CCODE_LIGHT_GREEN          = TERM_CCODE_GREEN + 8,
+        TERM_CCODE_LIGHT_YELLOW         = TERM_CCODE_YELLOW + 8,
+        TERM_CCODE_LIGHT_BLUE           = TERM_CCODE_BLUE + 8,
+        TERM_CCODE_LIGHT_MAGENTA        = TERM_CCODE_MAGENTA + 8,
+        TERM_CCODE_LIGHT_CYAN           = TERM_CCODE_CYAN + 8,
+        TERM_CCODE_LIGHT_WHITE          = TERM_CCODE_WHITE + 8,
+
+        /* pseudo colors */
+        TERM_CCODE_FG,                                                  /* selected foreground color */
+        TERM_CCODE_BG,                                                  /* selected background color */
+        TERM_CCODE_RGB,                                                 /* color is specified as RGB */
+
+        TERM_CCODE_CNT,
+};
+
+struct term_color {
+        uint8_t ccode;
+        uint8_t red;
+        uint8_t green;
+        uint8_t blue;
+};
+
+struct term_attr {
+        term_color fg;                          /* foreground color */
+        term_color bg;                          /* background color */
+
+        unsigned int bold : 1;                  /* bold font */
+        unsigned int italic : 1;                /* italic font */
+        unsigned int underline : 1;             /* underline text */
+        unsigned int inverse : 1;               /* inverse fg/bg */
+        unsigned int protect : 1;               /* protect from erase */
+        unsigned int blink : 1;                 /* blink text */
+};
+
+/*
+ * Cells
+ * The term_cell structure respresents a single cell in a terminal page. It
+ * contains the stored character, the age of the cell and all its attributes.
+ */
+
+struct term_cell {
+        term_char_t ch;         /* stored char or TERM_CHAR_NULL */
+        term_age_t age;         /* cell age or TERM_AGE_NULL */
+        term_attr attr;         /* cell attributes */
+        unsigned int cwidth;    /* cached term_char_lookup_width(cell->ch) */
+};
+
+/*
+ * Lines
+ * Instead of storing cells in a 2D array, we store them in an array of
+ * dynamically allocated lines. This way, scrolling can be implemented very
+ * fast without moving any cells at all. Similarly, the scrollback-buffer is
+ * much simpler to implement.
+ * We use term_line to store a single line. It contains an array of cells, a
+ * fill-state which remembers the amount of blanks on the right side, a
+ * separate age just for the line which can overwrite the age for all cells,
+ * and some management data.
+ */
+
+struct term_line {
+        term_line *lines_next;          /* linked-list for histories */
+        term_line *lines_prev;          /* linked-list for histories */
+
+        unsigned int width;             /* visible width of line */
+        unsigned int n_cells;           /* # of allocated cells */
+        term_cell *cells;               /* cell-array */
+
+        term_age_t age;                 /* line age */
+        unsigned int fill;              /* # of valid cells; starting left */
+};
+
+int term_line_new(term_line **out);
+term_line *term_line_free(term_line *line);
+
+#define _term_line_free_ _cleanup_(term_line_freep)
+DEFINE_TRIVIAL_CLEANUP_FUNC(term_line*, term_line_free);
+
+int term_line_reserve(term_line *line, unsigned int width, const term_attr *attr, term_age_t age, unsigned int protect_width);
+void term_line_set_width(term_line *line, unsigned int width);
+void term_line_write(term_line *line, unsigned int pos_x, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode);
+void term_line_insert(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age);
+void term_line_delete(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age);
+void term_line_append_combchar(term_line *line, unsigned int pos_x, uint32_t ucs4, term_age_t age);
+void term_line_erase(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age, bool keep_protected);
+void term_line_reset(term_line *line, const term_attr *attr, term_age_t age);
+
+void term_line_link(term_line *line, term_line **first, term_line **last);
+void term_line_link_tail(term_line *line, term_line **first, term_line **last);
+void term_line_unlink(term_line *line, term_line **first, term_line **last);
+
+#define TERM_LINE_LINK(_line, _head) term_line_link((_line), &(_head)->lines_first, &(_head)->lines_last)
+#define TERM_LINE_LINK_TAIL(_line, _head) term_line_link_tail((_line), &(_head)->lines_first, &(_head)->lines_last)
+#define TERM_LINE_UNLINK(_line, _head) term_line_unlink((_line), &(_head)->lines_first, &(_head)->lines_last)
diff --git a/src/libsystemd-terminal/term-page.c b/src/libsystemd-terminal/term-page.c
new file mode 100644
index 0000000..bfff3b1
--- /dev/null
+++ b/src/libsystemd-terminal/term-page.c
@@ -0,0 +1,1142 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 David Herrmann <dh.herrmann at gmail.com>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/*
+ * Terminal Page/Line/Cell/Char Handling
+ * This file implements page handling of a terminal. It is split into pages,
+ * lines, cells and characters. Each object is independent of the next upper
+ * object.
+ *
+ * The Terminal layer keeps each line of a terminal separate and dynamically
+ * allocated. This allows us to move lines from main-screen to history-buffers
+ * very fast. Same is true for scrolling, top/bottom borders and other buffer
+ * operations.
+ *
+ * While lines are dynamically allocated, cells are not. This would be a waste
+ * of memory and causes heavy fragmentation. Furthermore, cells are moved much
+ * less frequently than lines so the performance-penalty is pretty small.
+ * However, to support combining-characters, we have to initialize and cleanup
+ * cells properly and cannot just release the underlying memory. Therefore,
+ * cells are treated as proper objects despite being allocated in arrays.
+ *
+ * Each cell has a set of attributes and a stored character. This is usually a
+ * single Unicode character stored as 32bit UCS-4 char. However, we need to
+ * support Unicode combining-characters, therefore this gets more complicated.
+ * Characters themselves are represented by a "term_char_t" object. It
+ * should be treated as a normal integer and passed by value. The
+ * sorrounding struct is just to hide the internals. A term-char can contain a
+ * base character together with up to 2 combining-chars in a single integer.
+ * Only if you need more combining-chars (very unlikely!) a term-char is a
+ * pointer to an allocated storage. This requires you to always free term-char
+ * objects once no longer used (even though this is a no-op most of the time).
+ * Furthermore, term-char objects are not ref-counted so you must duplicate them
+ * in case you want to store it somewhere and retain a copy yourself. By
+ * convention, all functions that take a term-char object will not duplicate
+ * it but implicitly take ownership of the passed value. It's up to the caller
+ * to duplicate it beforehand, in case it wants to retain a copy.
+ *
+ * If it turns out, that more than 2 comb-chars become common in specific
+ * languages, we can try to optimize this. One idea is to ref-count allocated
+ * characters and store them in a hash-table (like gnome's libvte3 does). This
+ * way we will never have two allocated chars for the same content. Or we can
+ * simply put two uint64_t into a "term_char_t". This will slow down operations
+ * on systems that don't need that many comb-chars, but avoid the dynamic
+ * allocations on others.
+ * Anyhow, until we have proper benchmarks, we will keep the current code. It
+ * seems to compete very well with other solutions so far.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include "macro.h"
+#include "term-internal.h"
+#include "util.h"
+
+/* maximum UCS-4 character */
+#define CHAR_UCS4_MAX (0x10ffff)
+/* mask for valid UCS-4 characters (21bit) */
+#define CHAR_UCS4_MASK (0x1fffff)
+/* UCS-4 replacement character */
+#define CHAR_UCS4_REPLACEMENT (0xfffd)
+
+/* real storage behind "term_char_t" in case it's not packed */
+typedef struct term_character {
+        uint8_t n;
+        uint32_t codepoints[];
+} term_character;
+
+/*
+ * char_pack() takes 3 UCS-4 values and packs them into a term_char_t object.
+ * Note that UCS-4 chars only take 21 bits, so we still have the LSB as marker.
+ * We set it to 1 so others can distinguish it from pointers.
+ */
+static inline term_char_t char_pack(uint32_t v1, uint32_t v2, uint32_t v3) {
+        uint64_t packed, u1, u2, u3;
+
+        u1 = v1;
+        u2 = v2;
+        u3 = v3;
+
+        packed = 0x01;
+        packed |= (u1 & (uint64_t)CHAR_UCS4_MASK) << 43;
+        packed |= (u2 & (uint64_t)CHAR_UCS4_MASK) << 22;
+        packed |= (u3 & (uint64_t)CHAR_UCS4_MASK) <<  1;
+
+        return TERM_CHAR_INIT(packed);
+}
+
+#define char_pack1(_v1) char_pack2((_v1), CHAR_UCS4_MAX + 1)
+#define char_pack2(_v1, _v2) char_pack3((_v1), (_v2), CHAR_UCS4_MAX + 1)
+#define char_pack3(_v1, _v2, _v3) char_pack((_v1), (_v2), (_v3))
+
+/*
+ * char_unpack() is the inverse of char_pack(). It extracts the 3 stored UCS-4
+ * characters and returns them. Note that this does not validate the passed
+ * term_char_t. That's the responsibility of the caller.
+ * This returns the number of characters actually packed. This obviously is a
+ * number between 0 and 3 (inclusive).
+ */
+static inline uint8_t char_unpack(term_char_t packed, uint32_t *out_v1, uint32_t *out_v2, uint32_t *out_v3) {
+        uint32_t v1, v2, v3;
+
+        v1 = (packed._value >> 43) & (uint64_t)CHAR_UCS4_MASK;
+        v2 = (packed._value >> 22) & (uint64_t)CHAR_UCS4_MASK;
+        v3 = (packed._value >>  1) & (uint64_t)CHAR_UCS4_MASK;
+
+        if (out_v1)
+                *out_v1 = v1;
+        if (out_v2)
+                *out_v2 = v2;
+        if (out_v3)
+                *out_v3 = v3;
+
+        return (v1 > CHAR_UCS4_MAX) ? 0 :
+              ((v2 > CHAR_UCS4_MAX) ? 1 :
+              ((v3 > CHAR_UCS4_MAX) ? 2 :
+                                      3));
+}
+
+/* cast a term_char_t to a term_character* */
+static inline term_character *char_to_ptr(term_char_t ch) {
+        return (term_character*)(unsigned long)ch._value;
+}
+
+/* cast a term_character* to a term_char_t */
+static inline term_char_t char_from_ptr(term_character *c) {
+        return TERM_CHAR_INIT((unsigned long)c);
+}
+
+/*
+ * char_alloc() allocates a properly aligned term_character object and returns
+ * a pointer to it. NULL is returned on allocation errors. The object will have
+ * enough room for @n following UCS-4 chars.
+ * Note that we allocate (n+1) characters and set the last one to 0 in case
+ * anyone prints this string for debugging.
+ */
+static term_character *char_alloc(uint8_t n) {
+        term_character *c;
+        int r;
+
+        r = posix_memalign((void**)&c,
+                           MAX(sizeof(void*), (size_t)2),
+                           sizeof(*c) + sizeof(*c->codepoints) * (n + 1));
+        if (r)
+                return NULL;
+
+        c->n = n;
+        c->codepoints[n] = 0;
+
+        return c;
+}
+
+/*
+ * char_free() frees the memory allocated via char_alloc(). It is safe to call
+ * this on any term_char_t, only allocated characters are freed.
+ */
+static inline void char_free(term_char_t ch) {
+        if (term_char_is_allocated(ch))
+                free(char_to_ptr(ch));
+}
+
+/*
+ * This appends @append_ucs4 to the existing character @base and returns
+ * it as a new character. In case that's not possible, @base is returned. The
+ * caller can use term_char_same() to test whether the returned character was
+ * freshly allocated or not.
+ */
+static term_char_t char_build(term_char_t base, uint32_t append_ucs4) {
+        /* soft-limit for combining-chars; hard-limit is currently 255 */
+        const size_t climit = 64;
+        term_character *c;
+        uint32_t buf[3], *t;
+        uint8_t n;
+
+        /* ignore invalid UCS-4 */
+        if (append_ucs4 > CHAR_UCS4_MAX)
+                return base;
+
+        if (term_char_is_null(base)) {
+                return char_pack1(append_ucs4);
+        } else if (!term_char_is_allocated(base)) {
+                /* unpack and try extending the packed character */
+                n = char_unpack(base, &buf[0], &buf[1], &buf[2]);
+
+                switch (n) {
+                case 0:
+                        return char_pack1(append_ucs4);
+                case 1:
+                        if (climit < 2)
+                                return base;
+
+                        return char_pack2(buf[0], append_ucs4);
+                case 2:
+                        if (climit < 3)
+                                return base;
+
+                        return char_pack3(buf[0], buf[1], append_ucs4);
+                default:
+                        /* fallthrough */
+                        break;
+                }
+
+                /* already fully packed, we need to allocate a new one */
+                t = buf;
+        } else {
+                /* already an allocated type, we need to allocate a new one */
+                c = char_to_ptr(base);
+                t = c->codepoints;
+                n = c->n;
+        }
+
+        /* bail out if soft-limit is reached */
+        if (n >= climit)
+                return base;
+
+        /* allocate new char */
+        c = char_alloc(n + 1);
+        if (!c)
+                return base;
+
+        memcpy(c->codepoints, t, sizeof(*t) * n);
+        c->codepoints[n] = append_ucs4;
+
+        return char_from_ptr(c);
+}
+
+/**
+ * term_char_set() - Reset character to a single UCS-4 character
+ * @previous: term-char to reset
+ * @append_ucs4: UCS-4 char to set
+ *
+ * This frees all resources in @previous and re-initializes it to @append_ucs4.
+ * The new char is returned.
+ *
+ * Usually, this is used like this:
+ *   obj->ch = term_char_set(obj->ch, ucs4);
+ *
+ * Returns: The previous character reset to @append_ucs4.
+ */
+term_char_t term_char_set(term_char_t previous, uint32_t append_ucs4) {
+        char_free(previous);
+        return char_build(TERM_CHAR_NULL, append_ucs4);
+}
+
+/**
+ * term_char_merge() - Merge UCS-4 char at the end of an existing char
+ * @base: existing term-char
+ * @append_ucs4: UCS-4 character to append
+ *
+ * This appends @append_ucs4 to @base and returns the result. @base is
+ * invalidated by this function and must no longer be used. The returned value
+ * replaces the old one.
+ *
+ * Usually, this is used like this:
+ *   obj->ch = term_char_merge(obj->ch, ucs4);
+ *
+ * Returns: The new merged character.
+ */
+term_char_t term_char_merge(term_char_t base, uint32_t append_ucs4) {
+        term_char_t ch;
+
+        ch = char_build(base, append_ucs4);
+        if (!term_char_same(ch, base))
+                term_char_free(base);
+
+        return ch;
+}
+
+/**
+ * term_char_dup() - Duplicate character
+ * @ch: character to duplicate
+ *
+ * This duplicates a term-character. In case the character is not allocated,
+ * nothing is done. Otherwise, the underlying memory is copied and returned. You
+ * need to call term_char_free() on the returned character to release it again.
+ * On allocation errors, a replacement character is returned. Therefore, the
+ * caller can safely assume that this function always succeeds.
+ *
+ * Returns: The duplicated term-character.
+ */
+term_char_t term_char_dup(term_char_t ch) {
+        term_character *c, *newc;
+
+        if (!term_char_is_allocated(ch))
+                return ch;
+
+        c = char_to_ptr(ch);
+        newc = char_alloc(c->n);
+        if (!newc)
+                return char_pack1(CHAR_UCS4_REPLACEMENT);
+
+        memcpy(newc->codepoints, c->codepoints, sizeof(*c->codepoints) * c->n);
+        return char_from_ptr(newc);
+}
+
+/**
+ * term_char_dup_append() - Duplicate tsm-char with UCS-4 character appended
+ * @base: existing term-char
+ * @append_ucs4: UCS-4 character to append
+ *
+ * This is similar to term_char_merge(), but it returns a separately allocated
+ * character. That is, @base will stay valid after this returns and is not
+ * touched. In case the append-operation fails, @base is duplicated and
+ * returned. That is, the returned char is always independent of @base.
+ *
+ * Returns: Newly allocated character with @append_ucs4 appended to @base.
+ */
+term_char_t term_char_dup_append(term_char_t base, uint32_t append_ucs4) {
+        term_char_t ch;
+
+        ch = char_build(base, append_ucs4);
+        if (term_char_same(ch, base))
+                ch = term_char_dup(base);
+
+        return ch;
+}
+
+/**
+ * term_char_resolve() - Retrieve the UCS-4 string for a term-char
+ * @ch: character to resolve
+ * @s: storage for size of string or NULL
+ * @b: storage for string or NULL
+ *
+ * This takes a term-character and returns the UCS-4 string associated with it.
+ * In case @ch is not allocated, the string is stored in @b (in case @b is NULL
+ * static storage is used). Otherwise, a pointer to the allocated storage is
+ * returned.
+ *
+ * The returned string is only valid as long as @ch and @b are valid. The string
+ * is zero-terminated and can safely be printed via long-character printf().
+ * The length of the string excluding the zero-character is returned in @s.
+ *
+ * This never returns NULL. Even if the size is 0, this points to a buffer of at
+ * least a zero-terminator.
+ *
+ * Returns: The UCS-4 string-representation of @ch, and its size in @s.
+ */
+const uint32_t *term_char_resolve(term_char_t ch, size_t *s, term_charbuf_t *b) {
+        static term_charbuf_t static_b;
+        term_character *c;
+        uint32_t *cache;
+        size_t len;
+
+        if (b)
+                cache = b->buf;
+        else
+                cache = static_b.buf;
+
+        if (term_char_is_null(ch)) {
+                len = 0;
+                cache[0] = 0;
+        } else if (term_char_is_allocated(ch)) {
+                c = char_to_ptr(ch);
+                len = c->n;
+                cache = c->codepoints;
+        } else {
+                len = char_unpack(ch, &cache[0], &cache[1], &cache[2]);
+                cache[len] = 0;
+        }
+
+        if (s)
+                *s = len;
+
+        return cache;
+}
+
+/**
+ * term_char_lookup_width() - Lookup cell-width of a character
+ * @ch: character to return cell-width for
+ *
+ * This is an equivalent of wcwidth() for term_char_t. It can deal directly
+ * with UCS-4 and combining-characters and avoids the mess that is wchar_t and
+ * locale handling.
+ *
+ * Returns: 0 for unprintable characters, >0 for everything else.
+ */
+unsigned int term_char_lookup_width(term_char_t ch) {
+        term_charbuf_t b;
+        const uint32_t *str;
+        unsigned int max;
+        size_t i, len;
+        int r;
+
+        max = 0;
+        str = term_char_resolve(ch, &len, &b);
+
+        for (i = 0; i < len; ++i) {
+                /*
+                 * Oh god, C99 locale handling strikes again: wcwidth() expects
+                 * wchar_t, but there is no way for us to know the
+                 * internal encoding of wchar_t. Moreover, it is nearly
+                 * impossible to convert UCS-4 into wchar_t (except for iconv,
+                 * which is way too much overhead).
+                 * Therefore, we use our own copy of wcwidth(). Lets just hope
+                 * that glibc will one day export it's internal UCS-4 and UTF-8
+                 * helpers for direct use.
+                 */
+                assert_cc(sizeof(wchar_t) >= 4);
+                r = mk_wcwidth((wchar_t)str[i]);
+                if (r > 0 && (unsigned int)r > max)
+                        max = r;
+        }
+
+        return max;
+}
+
+/**
+ * term_cell_init() - Initialize a new cell
+ * @cell: cell to initialize
+ * @ch: character to set on the cell or TERM_CHAR_NULL
+ * @cwidth: character width of @ch
+ * @attr: attributes to set on the cell or NULL
+ * @age: age to set on the cell or TERM_AGE_NULL
+ *
+ * This initializes a new cell. The backing-memory of the cell must be allocated
+ * by the caller beforehand. The caller is responsible to destroy the cell via
+ * term_cell_destroy() before freeing the backing-memory.
+ *
+ * It is safe (and supported!) to use:
+ *   zero(*c);
+ * instead of:
+ *   term_cell_init(c, TERM_CHAR_NULL, NULL, TERM_AGE_NULL);
+ *
+ * Note that this call takes ownership of @ch. If you want to use it yourself
+ * after this call, you need to duplicate it before calling this.
+ */
+static void term_cell_init(term_cell *cell, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age) {
+        assert(cell);
+
+        cell->ch = ch;
+        cell->cwidth = cwidth;
+        cell->age = age;
+
+        if (attr)
+                memcpy(&cell->attr, attr, sizeof(*attr));
+        else
+                zero(cell->attr);
+}
+
+/**
+ * term_cell_destroy() - Destroy previously initialized cell
+ * @cell: cell to destroy or NULL
+ *
+ * This releases all resources associated with a cell. The backing memory is
+ * kept as-is. It's the responsibility of the caller to manage it.
+ *
+ * You must not call any other cell operations on this cell after this call
+ * returns. You must re-initialize the cell via term_cell_init() before you can
+ * use it again.
+ *
+ * If @cell is NULL, this is a no-op.
+ */
+static void term_cell_destroy(term_cell *cell) {
+        if (!cell)
+                return;
+
+        term_char_free(cell->ch);
+}
+
+/**
+ * term_cell_set() - Change contents of a cell
+ * @cell: cell to modify
+ * @ch: character to set on the cell or cell->ch
+ * @cwidth: character width of @ch or cell->cwidth
+ * @attr: attributes to set on the cell or NULL
+ * @age: age to set on the cell or cell->age
+ *
+ * This changes the contents of a cell. It can be used to change the character,
+ * attributes and age. To keep the current character, pass cell->ch as @ch. To
+ * reset the current attributes, pass NULL. To keep the current age, pass
+ * cell->age.
+ *
+ * This call takes ownership of @ch. You need to duplicate it first, in case you
+ * want to use it for your own purposes after this call.
+ *
+ * The cell must have been initialized properly before calling this. See
+ * term_cell_init().
+ */
+static void term_cell_set(term_cell *cell, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age) {
+        assert(cell);
+
+        if (!term_char_same(ch, cell->ch)) {
+                term_char_free(cell->ch);
+                cell->ch = ch;
+        }
+
+        cell->cwidth = cwidth;
+        cell->age = age;
+
+        if (attr)
+                memcpy(&cell->attr, attr, sizeof(*attr));
+        else
+                zero(cell->attr);
+}
+
+/**
+ * term_cell_append() - Append a combining-char to a cell
+ * @cell: cell to modify
+ * @ucs4: UCS-4 character to append to the cell
+ * @age: new age to set on the cell or cell->age
+ *
+ * This appends a combining-character to a cell. No validation of the UCS-4
+ * character is done, so this can be used to append any character. Additionally,
+ * this can update the age of the cell.
+ *
+ * The cell must have been initialized properly before calling this. See
+ * term_cell_init().
+ */
+static void term_cell_append(term_cell *cell, uint32_t ucs4, term_age_t age) {
+        assert(cell);
+
+        cell->ch = term_char_merge(cell->ch, ucs4);
+        cell->age = age;
+}
+
+/**
+ * term_cell_init_n() - Initialize an array of cells
+ * @cells: pointer to an array of cells to initialize
+ * @n: number of cells
+ * @attr: attributes to set on all cells or NULL
+ * @age: age to set on all cells
+ *
+ * This is the same as term_cell_init() but initializes an array of cells.
+ * Furthermore, this always sets the character to TERM_CHAR_NULL.
+ * If you want to set a specific characters on all cells, you need to hard-code
+ * this loop and duplicate the character for each cell.
+ */
+static void term_cell_init_n(term_cell *cells, unsigned int n, const term_attr *attr, term_age_t age) {
+        for ( ; n > 0; --n, ++cells)
+                term_cell_init(cells, TERM_CHAR_NULL, 0, attr, age);
+}
+
+/**
+ * term_cell_destroy_n() - Destroy an array of cells
+ * @cells: pointer to an array of cells to destroy
+ * @n: number of cells
+ *
+ * This is the same as term_cell_destroy() but destroys an array of cells.
+ */
+static void term_cell_destroy_n(term_cell *cells, unsigned int n) {
+        for ( ; n > 0; --n, ++cells)
+                term_cell_destroy(cells);
+}
+
+/**
+ * term_cell_clear_n() - Clear contents of an array of cells
+ * @cells: pointer to an array of cells to modify
+ * @n: number of cells
+ * @attr: attributes to set on all cells or NULL
+ * @age: age to set on all cells
+ *
+ * This is the same as term_cell_set() but operates on an array of cells. Note
+ * that all characters are always set to TERM_CHAR_NULL, unlike term_cell_set()
+ * which takes the character as argument.
+ * If you want to set a specific characters on all cells, you need to hard-code
+ * this loop and duplicate the character for each cell.
+ */
+static void term_cell_clear_n(term_cell *cells, unsigned int n, const term_attr *attr, term_age_t age) {
+        for ( ; n > 0; --n, ++cells)
+                term_cell_set(cells, TERM_CHAR_NULL, 0, attr, age);
+}
+
+/**
+ * term_line_new() - Allocate a new line
+ * @out: place to store pointer to new line
+ *
+ * This allocates and initialized a new line. The line is unlinked and
+ * independent of any page. It can be used for any purpose. The initial
+ * cell-count is set to 0.
+ *
+ * The line has to be freed via term_line_free() once it's no longer needed.
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int term_line_new(term_line **out) {
+        _term_line_free_ term_line *line = NULL;
+
+        assert_return(out, -EINVAL);
+
+        line = new0(term_line, 1);
+        if (!line)
+                return -ENOMEM;
+
+        *out = line;
+        line = NULL;
+        return 0;
+}
+
+/**
+ * term_line_free() - Free a line
+ * @line: line to free or NULL
+ *
+ * This frees a line that was previously allocated via term_line_free(). All its
+ * cells are released, too.
+ *
+ * If @line is NULL, this is a no-op.
+ */
+term_line *term_line_free(term_line *line) {
+        if (!line)
+                return NULL;
+
+        term_cell_destroy_n(line->cells, line->n_cells);
+        free(line->cells);
+        free(line);
+
+        return NULL;
+}
+
+/**
+ * term_line_reserve() - Pre-allocate cells for a line
+ * @line: line to pre-allocate cells for
+ * @width: numbers of cells the line shall have pre-allocated
+ * @attr: attribute for all allocated cells or NULL
+ * @age: current age for all modifications
+ * @protect_width: width to protect from erasure
+ *
+ * This pre-allocates cells for this line. Please note that @width is the number
+ * of cells the line is guaranteed to have allocated after this call returns.
+ * It's not the number of cells that are added, neither is it the new width of
+ * the line.
+ *
+ * This function never frees memory. That is, reducing the line-width will
+ * always succeed, same is true for increasing the width to a previously set
+ * width.
+ *
+ * @attr and @age are used to initialize new cells. Additionally, any
+ * existing cell outside of the protected area specified by @protect_width are
+ * cleared and reset with @attr and @age.
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int term_line_reserve(term_line *line, unsigned int width, const term_attr *attr, term_age_t age, unsigned int protect_width) {
+        unsigned int min_width;
+        term_cell *t;
+
+        assert_return(line, -EINVAL);
+
+        /* reset existing cells if required */
+        min_width = MIN(line->n_cells, width);
+        if (min_width > protect_width)
+                term_cell_clear_n(line->cells + protect_width,
+                                  min_width - protect_width,
+                                  attr,
+                                  age);
+
+        /* allocate new cells if required */
+
+        if (width > line->n_cells) {
+                t = realloc_multiply(line->cells, sizeof(*t), width);
+                if (!t)
+                        return -ENOMEM;
+
+                if (!attr && !age)
+                        memzero(t + line->n_cells,
+                                sizeof(*t) * (width - line->n_cells));
+                else
+                        term_cell_init_n(t + line->n_cells,
+                                         width - line->n_cells,
+                                         attr,
+                                         age);
+
+                line->cells = t;
+                line->n_cells = width;
+        }
+
+        line->fill = MIN(line->fill, protect_width);
+
+        return 0;
+}
+
+/**
+ * term_line_set_width() - Change width of a line
+ * @line: line to modify
+ * @width: new width
+ *
+ * This changes the actual width of a line. It is the caller's responsibility
+ * to use term_line_reserve() to make sure enough space is allocated. If @width
+ * is greater than the allocated size, it is cropped.
+ *
+ * This does not modify any cells. Use term_line_reserve() or term_line_erase()
+ * to clear any newly added cells.
+ *
+ * NOTE: The fill state is cropped at line->width. Therefore, if you increase
+ *       the line-width afterwards, but there is a multi-cell character at the
+ *       end of the line that got cropped, then the fill-state will _not_ be
+ *       adjusted.
+ *       This means, the fill-state always includes the cells up to the start
+ *       of the right-most character, but it might or might not cover it until
+ *       its end. This should be totally fine, though. You should never access
+ *       multi-cell tails directly, anyway.
+ */
+void term_line_set_width(term_line *line, unsigned int width) {
+        assert(line);
+
+        if (width > line->n_cells)
+                width = line->n_cells;
+
+        line->width = width;
+        line->fill = MIN(line->fill, width);
+}
+
+/**
+ * line_insert() - Insert characters and move existing cells to the right
+ * @from: position to insert cells at
+ * @num: number of cells to insert
+ * @head_char: character that is set on the first cell
+ * @head_cwidth: character-length of @head_char
+ * @attr: attribute for all inserted cells or NULL
+ * @age: current age for all modifications
+ *
+ * The INSERT operation (or writes with INSERT_MODE) writes data at a specific
+ * position on a line and shifts the existing cells to the right. Cells that are
+ * moved beyond the right hand border are discarded.
+ *
+ * This helper contains the actual INSERT implementation which is independent of
+ * the data written. It works on cells, not on characters. The first cell is set
+ * to @head_char, all others are reset to TERM_CHAR_NULL. See each caller for a
+ * more detailed description.
+ */
+static inline void line_insert(term_line *line, unsigned int from, unsigned int num, term_char_t head_char, unsigned int head_cwidth, const term_attr *attr, term_age_t age) {
+        unsigned int i, rem, move;
+
+        if (from >= line->width)
+                return;
+        if (from + num < from || from + num > line->width)
+                num = line->width - from;
+        if (!num)
+                return;
+
+        move = line->width - from - num;
+        rem = MIN(num, move);
+
+        if (rem > 0) {
+                /*
+                 * Make room for @num cells; shift cells to the right if
+                 * required. @rem is the number of remaining cells that we will
+                 * knock off on the right and overwrite during the right shift.
+                 *
+                 * For INSERT_MODE, @num/@rem are usually 1 or 2, @move is 50%
+                 * of the line on average. Therefore, the actual move is quite
+                 * heavy and we can safely invalidate cells manually instead of
+                 * the whole line.
+                 * However, for INSERT operations, any parameters are
+                 * possible. But we cannot place any assumption on its usage
+                 * across applications, so we just handle it the same as
+                 * INSERT_MODE and do per-cell invalidation.
+                 */
+
+                /* destroy cells that are knocked off on the right */
+                term_cell_destroy_n(line->cells + line->width - rem, rem);
+
+                /* move remaining bulk of cells */
+                memmove(line->cells + from + num,
+                        line->cells + from,
+                        sizeof(*line->cells) * move);
+
+                /* invalidate cells */
+                for (i = 0; i < move; ++i)
+                        line->cells[from + num + i].age = age;
+
+                /* initialize fresh head-cell */
+                term_cell_init(line->cells + from,
+                               head_char,
+                               head_cwidth,
+                               attr,
+                               age);
+
+                /* initialize fresh tail-cells */
+                term_cell_init_n(line->cells + from + 1,
+                                 num - 1,
+                                 attr,
+                                 age);
+
+                /* adjust fill-state */
+                DISABLE_WARNING_SHADOW;
+                line->fill = MIN(line->width,
+                                 MAX(line->fill + num,
+                                     from + num));
+                REENABLE_WARNING;
+        } else {
+                /* modify head-cell */
+                term_cell_set(line->cells + from,
+                              head_char,
+                              head_cwidth,
+                              attr,
+                              age);
+
+                /* reset tail-cells */
+                term_cell_clear_n(line->cells + from + 1,
+                                  num - 1,
+                                  attr,
+                                  age);
+
+                /* adjust fill-state */
+                line->fill = line->width;
+        }
+}
+
+/**
+ * term_line_write() - Write to a single, specific cell
+ * @line: line to write to
+ * @pos_x: x-position of cell in @line to write to
+ * @ch: character to write to the cell
+ * @cwidth: character width of @ch
+ * @attr: attributes to set on the cell or NULL
+ * @age: current age for all modifications
+ * @insert_mode: true if INSERT-MODE is enabled
+ *
+ * This writes to a specific cell in a line. The cell is addressed by its
+ * X-position @pos_x. If that cell does not exist, this is a no-op.
+ *
+ * @ch and @attr are set on this cell.
+ *
+ * If @insert_mode is true, this inserts the character instead of overwriting
+ * existing data (existing data is now moved to the right before writing).
+ *
+ * This function is the low-level handler of normal writes to a terminal.
+ */
+void term_line_write(term_line *line, unsigned int pos_x, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode) {
+        unsigned int len;
+
+        assert(line);
+
+        if (pos_x >= line->width)
+                return;
+
+        len = MAX(1U, cwidth);
+        if (pos_x + len < pos_x || pos_x + len > line->width)
+                len = line->width - pos_x;
+        if (!len)
+                return;
+
+        if (insert_mode) {
+                /* Use line_insert() to insert the character-head and fill
+                 * the remains with NULLs. */
+                line_insert(line, pos_x, len, ch, cwidth, attr, age);
+        } else {
+                /* modify head-cell */
+                term_cell_set(line->cells + pos_x, ch, cwidth, attr, age);
+
+                /* reset tail-cells */
+                term_cell_clear_n(line->cells + pos_x + 1,
+                                  len - 1,
+                                  attr,
+                                  age);
+
+                /* adjust fill-state */
+                DISABLE_WARNING_SHADOW;
+                line->fill = MIN(line->width,
+                                 MAX(line->fill,
+                                     pos_x + len));
+                REENABLE_WARNING;
+        }
+}
+
+/**
+ * term_line_insert() - Insert empty cells
+ * @line: line to insert empty cells into
+ * @from: x-position where to insert cells
+ * @num: number of cells to insert
+ * @attr: attributes to set on the cells or NULL
+ * @age: current age for all modifications
+ *
+ * This inserts @num empty cells at position @from in line @line. All existing
+ * cells to the right are shifted to make room for the new cells. Cells that get
+ * pushed beyond the right hand border are discarded.
+ */
+void term_line_insert(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age) {
+        /* use line_insert() to insert @num empty cells */
+        return line_insert(line, from, num, TERM_CHAR_NULL, 0, attr, age);
+}
+
+/**
+ * term_line_delete() - Delete cells from line
+ * @line: line to delete cells from
+ * @from: position to delete cells at
+ * @num: number of cells to delete
+ * @attr: attributes to set on any new cells
+ * @age: current age for all modifications
+ *
+ * Delete cells from a line. All cells to the right of the deleted cells are
+ * shifted to the left to fill the empty space. New cells appearing on the right
+ * hand border are cleared and initialized with @attr.
+ */
+void term_line_delete(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age) {
+        unsigned int rem, move, i;
+
+        assert(line);
+
+        if (from >= line->width)
+                return;
+        if (from + num < from || from + num > line->width)
+                num = line->width - from;
+        if (!num)
+                return;
+
+        /* destroy and move as many upfront as possible */
+        move = line->width - from - num;
+        rem = MIN(num, move);
+        if (rem > 0) {
+                /* destroy to be removed cells */
+                term_cell_destroy_n(line->cells + from, rem);
+
+                /* move tail upfront */
+                memmove(line->cells + from,
+                        line->cells + from + num,
+                        sizeof(*line->cells) * move);
+
+                /* invalidate copied cells */
+                for (i = 0; i < move; ++i)
+                        line->cells[from + i].age = age;
+
+                /* initialize tail that was moved away */
+                term_cell_init_n(line->cells + line->width - rem,
+                                 rem,
+                                 attr,
+                                 age);
+
+                /* reset remaining cells in case the move was too small */
+                if (num > move)
+                        term_cell_clear_n(line->cells + from + move,
+                                          num - move,
+                                          attr,
+                                          age);
+        } else {
+                /* reset cells */
+                term_cell_clear_n(line->cells + from,
+                                  num,
+                                  attr,
+                                  age);
+        }
+
+        /* adjust fill-state */
+        if (from + num < line->fill)
+                line->fill -= num;
+        else if (from < line->fill)
+                line->fill = from;
+}
+
+/**
+ * term_line_append_combchar() - Append combining char to existing cell
+ * @line: line to modify
+ * @pos_x: position of cell to append combining char to
+ * @ucs4: combining character to append
+ * @age: current age for all modifications
+ *
+ * Unicode allows trailing combining characters, which belong to the
+ * char in front of them. The caller is responsible of detecting
+ * combining characters and calling term_line_append_combchar() instead of
+ * term_line_write(). This simply appends the char to the correct cell then.
+ * If the cell is not in the visible area, this call is skipped.
+ *
+ * Note that control-sequences are not 100% compatible with combining
+ * characters as they require delayed parsing. However, we must handle
+ * control-sequences immediately. Therefore, there might be trailing
+ * combining chars that should be discarded by the parser.
+ * However, to prevent programming errors, we're also being pedantic
+ * here and discard weirdly placed combining chars. This prevents
+ * situations were invalid content is parsed into the terminal and you
+ * might end up with cells containing only combining chars.
+ *
+ * Long story short: To get combining-characters working with old-fashioned
+ * terminal-emulation, we parse them exclusively for direct cell-writes. Other
+ * combining-characters are usually simply discarded and ignored.
+ */
+void term_line_append_combchar(term_line *line, unsigned int pos_x, uint32_t ucs4, term_age_t age) {
+        assert(line);
+
+        if (pos_x >= line->width)
+                return;
+
+        /* Unused cell? Skip appending any combining chars then. */
+        if (term_char_is_null(line->cells[pos_x].ch))
+                return;
+
+        term_cell_append(line->cells + pos_x, ucs4, age);
+}
+
+/**
+ * term_line_erase() - Erase parts of a line
+ * @line: line to modify
+ * @from: position to start the erase
+ * @num: number of cells to erase
+ * @attr: attributes to initialize erased cells with
+ * @age: current age for all modifications
+ * @keep_protected: true if protected cells should be kept
+ *
+ * This is the standard erase operation. It clears all cells in the targetted
+ * area and re-initializes them. Cells to the right are not shifted left, you
+ * must use DELETE to achieve that. Cells outside the visible area are skipped.
+ *
+ * If @keep_protected is true, protected cells will not be erased.
+ */
+void term_line_erase(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age, bool keep_protected) {
+        term_cell *cell;
+        unsigned int i, last_protected;
+
+        assert(line);
+
+        if (from >= line->width)
+                return;
+        if (from + num < from || from + num > line->width)
+                num = line->width - from;
+        if (!num)
+                return;
+
+        last_protected = 0;
+        for (i = 0; i < num; ++i) {
+                cell = line->cells + from + i;
+                if (keep_protected && cell->attr.protect) {
+                        /* only count protected-cells inside the fill-region */
+                        if (from + i < line->fill)
+                                last_protected = from + i;
+
+                        continue;
+                }
+
+                term_cell_set(cell, TERM_CHAR_NULL, 0, attr, age);
+        }
+
+        /* Adjust fill-state. This is a bit tricks, we can only adjust it in
+         * case the erase-region starts inside the fill-region and ends at the
+         * tail or beyond the fill-region. Otherwise, the current fill-state
+         * stays as it was.
+         * Furthermore, we must account for protected cells. The loop above
+         * ensures that protected-cells are only accounted for if they're
+         * inside the fill-region. */
+        if (from < line->fill && from + num >= line->fill)
+                line->fill = MAX(from, last_protected);
+}
+
+/**
+ * term_line_reset() - Reset a line
+ * @line: line to reset
+ * @attr: attributes to initialize all cells with
+ * @age: current age for all modifications
+ *
+ * This resets all visible cells of a line and sets their attributes and ages
+ * to @attr and @age. This is equivalent to erasing a whole line via
+ * term_line_erase().
+ */
+void term_line_reset(term_line *line, const term_attr *attr, term_age_t age) {
+        assert(line);
+
+        return term_line_erase(line, 0, line->width, attr, age, 0);
+}
+
+/**
+ * term_line_link() - Link line in front of a list
+ * @line: line to link
+ * @first: member pointing to first entry
+ * @last: member pointing to last entry
+ *
+ * This links a line into a list of lines. The line is inserted at the front and
+ * must not be linked, yet. See the TERM_LINE_LINK() macro for an easier usage of
+ * this.
+ */
+void term_line_link(term_line *line, term_line **first, term_line **last) {
+        assert(line);
+        assert(first);
+        assert(last);
+        assert(!line->lines_prev);
+        assert(!line->lines_next);
+
+        line->lines_prev = NULL;
+        line->lines_next = *first;
+        if (*first)
+                (*first)->lines_prev = line;
+        else
+                *last = line;
+        *first = line;
+}
+
+/**
+ * term_line_link_tail() - Link line at tail of a list
+ * @line: line to link
+ * @first: member pointing to first entry
+ * @last: member pointing to last entry
+ *
+ * Same as term_line_link() but links the line at the tail.
+ */
+void term_line_link_tail(term_line *line, term_line **first, term_line **last) {
+        assert(line);
+        assert(first);
+        assert(last);
+        assert(!line->lines_prev);
+        assert(!line->lines_next);
+
+        line->lines_next = NULL;
+        line->lines_prev = *last;
+        if (*last)
+                (*last)->lines_next = line;
+        else
+                *first = line;
+        *last = line;
+}
+
+/**
+ * term_line_unlink() - Unlink line from a list
+ * @line: line to unlink
+ * @first: member pointing to first entry
+ * @last: member pointing to last entry
+ *
+ * This unlinks a previously linked line. See TERM_LINE_UNLINK() for an easier to
+ * use macro.
+ */
+void term_line_unlink(term_line *line, term_line **first, term_line **last) {
+        assert(line);
+        assert(first);
+        assert(last);
+
+        if (line->lines_prev)
+                line->lines_prev->lines_next = line->lines_next;
+        else
+                *first = line->lines_next;
+        if (line->lines_next)
+                line->lines_next->lines_prev = line->lines_prev;
+        else
+                *last = line->lines_prev;
+
+        line->lines_prev = NULL;
+        line->lines_next = NULL;
+}
diff --git a/src/libsystemd-terminal/term-wcwidth.c b/src/libsystemd-terminal/term-wcwidth.c
new file mode 100644
index 0000000..443161c
--- /dev/null
+++ b/src/libsystemd-terminal/term-wcwidth.c
@@ -0,0 +1,313 @@
+/*
+ * (Minimal changes made by David Herrmann, to make clean for inclusion in
+ *  systemd. Original header follows.)
+ *
+ * This is an implementation of wcwidth() and wcswidth() (defined in
+ * IEEE Std 1002.1-2001) for Unicode.
+ *
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
+ *
+ * In fixed-width output devices, Latin characters all occupy a single
+ * "cell" position of equal width, whereas ideographic CJK characters
+ * occupy two such cells. Interoperability between terminal-line
+ * applications and (teletype-style) character terminals using the
+ * UTF-8 encoding requires agreement on which character should advance
+ * the cursor by how many cell positions. No established formal
+ * standards exist at present on which Unicode character shall occupy
+ * how many cell positions on character terminals. These routines are
+ * a first attempt of defining such behavior based on simple rules
+ * applied to data provided by the Unicode Consortium.
+ *
+ * For some graphical characters, the Unicode standard explicitly
+ * defines a character-cell width via the definition of the East Asian
+ * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
+ * In all these cases, there is no ambiguity about which width a
+ * terminal shall use. For characters in the East Asian Ambiguous (A)
+ * class, the width choice depends purely on a preference of backward
+ * compatibility with either historic CJK or Western practice.
+ * Choosing single-width for these characters is easy to justify as
+ * the appropriate long-term solution, as the CJK practice of
+ * displaying these characters as double-width comes from historic
+ * implementation simplicity (8-bit encoded characters were displayed
+ * single-width and 16-bit ones double-width, even for Greek,
+ * Cyrillic, etc.) and not any typographic considerations.
+ *
+ * Much less clear is the choice of width for the Not East Asian
+ * (Neutral) class. Existing practice does not dictate a width for any
+ * of these characters. It would nevertheless make sense
+ * typographically to allocate two character cells to characters such
+ * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
+ * represented adequately with a single-width glyph. The following
+ * routines at present merely assign a single-cell width to all
+ * neutral characters, in the interest of simplicity. This is not
+ * entirely satisfactory and should be reconsidered before
+ * establishing a formal standard in this area. At the moment, the
+ * decision which Not East Asian (Neutral) characters should be
+ * represented by double-width glyphs cannot yet be answered by
+ * applying a simple rule from the Unicode database content. Setting
+ * up a proper standard for the behavior of UTF-8 character terminals
+ * will require a careful analysis not only of each Unicode character,
+ * but also of each presentation form, something the author of these
+ * routines has avoided to do so far.
+ *
+ * http://www.unicode.org/unicode/reports/tr11/
+ *
+ * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
+ *
+ * Permission to use, copy, modify, and distribute this software
+ * for any purpose and without fee is hereby granted. The author
+ * disclaims all warranties with regard to this software.
+ *
+ * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+
+#include <wchar.h>
+#include "term-internal.h"
+
+struct interval {
+  int first;
+  int last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int bisearch(wchar_t ucs, const struct interval *table, int max) {
+  int min = 0;
+  int mid;
+
+  if (ucs < table[0].first || ucs > table[max].last)
+    return 0;
+  while (max >= min) {
+    mid = (min + max) / 2;
+    if (ucs > table[mid].last)
+      min = mid + 1;
+    else if (ucs < table[mid].first)
+      max = mid - 1;
+    else
+      return 1;
+  }
+
+  return 0;
+}
+
+
+/* The following two functions define the column width of an ISO 10646
+ * character as follows:
+ *
+ *    - The null character (U+0000) has a column width of 0.
+ *
+ *    - Other C0/C1 control characters and DEL will lead to a return
+ *      value of -1.
+ *
+ *    - Non-spacing and enclosing combining characters (general
+ *      category code Mn or Me in the Unicode database) have a
+ *      column width of 0.
+ *
+ *    - SOFT HYPHEN (U+00AD) has a column width of 1.
+ *
+ *    - Other format characters (general category code Cf in the Unicode
+ *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
+ *
+ *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
+ *      have a column width of 0.
+ *
+ *    - Spacing characters in the East Asian Wide (W) or East Asian
+ *      Full-width (F) category as defined in Unicode Technical
+ *      Report #11 have a column width of 2.
+ *
+ *    - All remaining characters (including all printable
+ *      ISO 8859-1 and WGL4 characters, Unicode control characters,
+ *      etc.) have a column width of 1.
+ *
+ * This implementation assumes that wchar_t characters are encoded
+ * in ISO 10646.
+ */
+
+int mk_wcwidth(wchar_t ucs)
+{
+  /* sorted list of non-overlapping intervals of non-spacing characters */
+  /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
+  static const struct interval combining[] = {
+    { 0x0300, 0x036F }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 },
+    { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
+    { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 },
+    { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 },
+    { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
+    { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
+    { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 0x0901, 0x0902 },
+    { 0x093C, 0x093C }, { 0x0941, 0x0948 }, { 0x094D, 0x094D },
+    { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 },
+    { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD },
+    { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C },
+    { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D },
+    { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC },
+    { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD },
+    { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C },
+    { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D },
+    { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 },
+    { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 },
+    { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC },
+    { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
+    { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
+    { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
+    { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
+    { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
+    { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
+    { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
+    { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
+    { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
+    { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
+    { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x135F, 0x135F },
+    { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 },
+    { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD },
+    { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD },
+    { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 },
+    { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B },
+    { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 },
+    { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 },
+    { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF },
+    { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 },
+    { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F },
+    { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B },
+    { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F },
+    { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB },
+    { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F },
+    { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x1D167, 0x1D169 },
+    { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
+    { 0x1D242, 0x1D244 }, { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F },
+    { 0xE0100, 0xE01EF }
+  };
+
+  /* test for 8-bit control characters */
+  if (ucs == 0)
+    return 0;
+  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
+    return -1;
+
+  /* binary search in table of non-spacing characters */
+  if (bisearch(ucs, combining,
+               sizeof(combining) / sizeof(struct interval) - 1))
+    return 0;
+
+  /* if we arrive here, ucs is not a combining or C0/C1 control character */
+
+  return 1 +
+    (ucs >= 0x1100 &&
+     (ucs <= 0x115f ||                    /* Hangul Jamo init. consonants */
+      ucs == 0x2329 || ucs == 0x232a ||
+      (ucs >= 0x2e80 && ucs <= 0xa4cf &&
+       ucs != 0x303f) ||                  /* CJK ... Yi */
+      (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
+      (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
+      (ucs >= 0xfe10 && ucs <= 0xfe19) || /* Vertical forms */
+      (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
+      (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
+      (ucs >= 0xffe0 && ucs <= 0xffe6) ||
+      (ucs >= 0x20000 && ucs <= 0x2fffd) ||
+      (ucs >= 0x30000 && ucs <= 0x3fffd)));
+}
+
+
+int mk_wcswidth(const wchar_t *pwcs, size_t n)
+{
+  int w, width = 0;
+
+  for (;*pwcs && n-- > 0; pwcs++)
+    if ((w = mk_wcwidth(*pwcs)) < 0)
+      return -1;
+    else
+      width += w;
+
+  return width;
+}
+
+
+/*
+ * The following functions are the same as mk_wcwidth() and
+ * mk_wcswidth(), except that spacing characters in the East Asian
+ * Ambiguous (A) category as defined in Unicode Technical Report #11
+ * have a column width of 2. This variant might be useful for users of
+ * CJK legacy encodings who want to migrate to UCS without changing
+ * the traditional terminal character-width behaviour. It is not
+ * otherwise recommended for general use.
+ */
+int mk_wcwidth_cjk(wchar_t ucs)
+{
+  /* sorted list of non-overlapping intervals of East Asian Ambiguous
+   * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
+  static const struct interval ambiguous[] = {
+    { 0x00A1, 0x00A1 }, { 0x00A4, 0x00A4 }, { 0x00A7, 0x00A8 },
+    { 0x00AA, 0x00AA }, { 0x00AE, 0x00AE }, { 0x00B0, 0x00B4 },
+    { 0x00B6, 0x00BA }, { 0x00BC, 0x00BF }, { 0x00C6, 0x00C6 },
+    { 0x00D0, 0x00D0 }, { 0x00D7, 0x00D8 }, { 0x00DE, 0x00E1 },
+    { 0x00E6, 0x00E6 }, { 0x00E8, 0x00EA }, { 0x00EC, 0x00ED },
+    { 0x00F0, 0x00F0 }, { 0x00F2, 0x00F3 }, { 0x00F7, 0x00FA },
+    { 0x00FC, 0x00FC }, { 0x00FE, 0x00FE }, { 0x0101, 0x0101 },
+    { 0x0111, 0x0111 }, { 0x0113, 0x0113 }, { 0x011B, 0x011B },
+    { 0x0126, 0x0127 }, { 0x012B, 0x012B }, { 0x0131, 0x0133 },
+    { 0x0138, 0x0138 }, { 0x013F, 0x0142 }, { 0x0144, 0x0144 },
+    { 0x0148, 0x014B }, { 0x014D, 0x014D }, { 0x0152, 0x0153 },
+    { 0x0166, 0x0167 }, { 0x016B, 0x016B }, { 0x01CE, 0x01CE },
+    { 0x01D0, 0x01D0 }, { 0x01D2, 0x01D2 }, { 0x01D4, 0x01D4 },
+    { 0x01D6, 0x01D6 }, { 0x01D8, 0x01D8 }, { 0x01DA, 0x01DA },
+    { 0x01DC, 0x01DC }, { 0x0251, 0x0251 }, { 0x0261, 0x0261 },
+    { 0x02C4, 0x02C4 }, { 0x02C7, 0x02C7 }, { 0x02C9, 0x02CB },
+    { 0x02CD, 0x02CD }, { 0x02D0, 0x02D0 }, { 0x02D8, 0x02DB },
+    { 0x02DD, 0x02DD }, { 0x02DF, 0x02DF }, { 0x0391, 0x03A1 },
+    { 0x03A3, 0x03A9 }, { 0x03B1, 0x03C1 }, { 0x03C3, 0x03C9 },
+    { 0x0401, 0x0401 }, { 0x0410, 0x044F }, { 0x0451, 0x0451 },
+    { 0x2010, 0x2010 }, { 0x2013, 0x2016 }, { 0x2018, 0x2019 },
+    { 0x201C, 0x201D }, { 0x2020, 0x2022 }, { 0x2024, 0x2027 },
+    { 0x2030, 0x2030 }, { 0x2032, 0x2033 }, { 0x2035, 0x2035 },
+    { 0x203B, 0x203B }, { 0x203E, 0x203E }, { 0x2074, 0x2074 },
+    { 0x207F, 0x207F }, { 0x2081, 0x2084 }, { 0x20AC, 0x20AC },
+    { 0x2103, 0x2103 }, { 0x2105, 0x2105 }, { 0x2109, 0x2109 },
+    { 0x2113, 0x2113 }, { 0x2116, 0x2116 }, { 0x2121, 0x2122 },
+    { 0x2126, 0x2126 }, { 0x212B, 0x212B }, { 0x2153, 0x2154 },
+    { 0x215B, 0x215E }, { 0x2160, 0x216B }, { 0x2170, 0x2179 },
+    { 0x2190, 0x2199 }, { 0x21B8, 0x21B9 }, { 0x21D2, 0x21D2 },
+    { 0x21D4, 0x21D4 }, { 0x21E7, 0x21E7 }, { 0x2200, 0x2200 },
+    { 0x2202, 0x2203 }, { 0x2207, 0x2208 }, { 0x220B, 0x220B },
+    { 0x220F, 0x220F }, { 0x2211, 0x2211 }, { 0x2215, 0x2215 },
+    { 0x221A, 0x221A }, { 0x221D, 0x2220 }, { 0x2223, 0x2223 },
+    { 0x2225, 0x2225 }, { 0x2227, 0x222C }, { 0x222E, 0x222E },
+    { 0x2234, 0x2237 }, { 0x223C, 0x223D }, { 0x2248, 0x2248 },
+    { 0x224C, 0x224C }, { 0x2252, 0x2252 }, { 0x2260, 0x2261 },
+    { 0x2264, 0x2267 }, { 0x226A, 0x226B }, { 0x226E, 0x226F },
+    { 0x2282, 0x2283 }, { 0x2286, 0x2287 }, { 0x2295, 0x2295 },
+    { 0x2299, 0x2299 }, { 0x22A5, 0x22A5 }, { 0x22BF, 0x22BF },
+    { 0x2312, 0x2312 }, { 0x2460, 0x24E9 }, { 0x24EB, 0x254B },
+    { 0x2550, 0x2573 }, { 0x2580, 0x258F }, { 0x2592, 0x2595 },
+    { 0x25A0, 0x25A1 }, { 0x25A3, 0x25A9 }, { 0x25B2, 0x25B3 },
+    { 0x25B6, 0x25B7 }, { 0x25BC, 0x25BD }, { 0x25C0, 0x25C1 },
+    { 0x25C6, 0x25C8 }, { 0x25CB, 0x25CB }, { 0x25CE, 0x25D1 },
+    { 0x25E2, 0x25E5 }, { 0x25EF, 0x25EF }, { 0x2605, 0x2606 },
+    { 0x2609, 0x2609 }, { 0x260E, 0x260F }, { 0x2614, 0x2615 },
+    { 0x261C, 0x261C }, { 0x261E, 0x261E }, { 0x2640, 0x2640 },
+    { 0x2642, 0x2642 }, { 0x2660, 0x2661 }, { 0x2663, 0x2665 },
+    { 0x2667, 0x266A }, { 0x266C, 0x266D }, { 0x266F, 0x266F },
+    { 0x273D, 0x273D }, { 0x2776, 0x277F }, { 0xE000, 0xF8FF },
+    { 0xFFFD, 0xFFFD }, { 0xF0000, 0xFFFFD }, { 0x100000, 0x10FFFD }
+  };
+
+  /* binary search in table of non-spacing characters */
+  if (bisearch(ucs, ambiguous,
+               sizeof(ambiguous) / sizeof(struct interval) - 1))
+    return 2;
+
+  return mk_wcwidth(ucs);
+}
+
+
+int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
+{
+  int w, width = 0;
+
+  for (;*pwcs && n-- > 0; pwcs++)
+    if ((w = mk_wcwidth_cjk(*pwcs)) < 0)
+      return -1;
+    else
+      width += w;
+
+  return width;
+}
diff --git a/src/libsystemd-terminal/test-term-page.c b/src/libsystemd-terminal/test-term-page.c
new file mode 100644
index 0000000..bba83ee
--- /dev/null
+++ b/src/libsystemd-terminal/test-term-page.c
@@ -0,0 +1,463 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2014 David Herrmann <dh.herrmann at gmail.com>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/*
+ * Terminal Page/Line/Cell/Char Tests
+ * This tests internals of terminal page, line, cell and char handling. It
+ * relies on some implementation details, so it might need to be updated if
+ * those internals are changed. They should be fairly obvious, though.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "macro.h"
+#include "term-internal.h"
+#include "util.h"
+
+#define MY_ASSERT_VALS __FILE__, __LINE__, __PRETTY_FUNCTION__
+#define MY_ASSERT_FORW _FILE, _LINE, _FUNC
+#define MY_ASSERT_ARGS const char *_FILE, int _LINE, const char *_FUNC
+#define MY_ASSERT(expr)                                                 \
+        do {                                                            \
+                if (_unlikely_(!(expr)))                                \
+                        log_assert_failed(#expr, _FILE, _LINE, _FUNC);  \
+        } while (false)                                                 \
+
+/*
+ * Character Tests
+ *
+ * These tests rely on some implementation details of term_char_t, including
+ * the way we pack characters and the internal layout of "term_char_t". These
+ * tests have to be updated once we change the implementation.
+ */
+
+#define PACK(v1, v2, v3) \
+                TERM_CHAR_INIT( \
+                        (((((uint64_t)v1) & 0x1fffffULL) << 43) | \
+                         ((((uint64_t)v2) & 0x1fffffULL) << 22) | \
+                         ((((uint64_t)v3) & 0x1fffffULL) <<  1) | \
+                         0x1) \
+                )
+#define PACK1(v1) PACK2((v1), 0x110000)
+#define PACK2(v1, v2) PACK3((v1), (v2), 0x110000)
+#define PACK3(v1, v2, v3) PACK((v1), (v2), (v3))
+
+static void test_term_char_misc(void) {
+        term_char_t c, t;
+
+        /* test TERM_CHAR_NULL handling */
+
+        c = TERM_CHAR_NULL;                     /* c is NULL */
+        assert_se(term_char_same(c, TERM_CHAR_NULL));
+        assert_se(term_char_equal(c, TERM_CHAR_NULL));
+        assert_se(term_char_is_null(c));
+        assert_se(term_char_is_null(TERM_CHAR_NULL));
+        assert_se(!term_char_is_allocated(c));
+
+        /* test single char handling */
+
+        t = term_char_dup_append(c, 'A');       /* t is >A< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_equal(c, t));
+        assert_se(!term_char_is_allocated(t));
+        assert_se(!term_char_is_null(t));
+
+        /* test basic combined char handling */
+
+        t = term_char_dup_append(t, '~');
+        t = term_char_dup_append(t, '^');       /* t is >A~^< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_is_allocated(t));
+        assert_se(!term_char_is_null(t));
+
+        c = term_char_dup_append(c, 'A');
+        c = term_char_dup_append(c, '~');
+        c = term_char_dup_append(c, '^');       /* c is >A~^< now */
+        assert_se(term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        /* test more than 2 comb-chars so the chars are allocated */
+
+        t = term_char_dup_append(t, '`');       /* t is >A~^`< now */
+        c = term_char_dup_append(c, '`');       /* c is >A~^`< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        /* test dup_append() on allocated chars */
+
+        term_char_free(t);
+        t = term_char_dup_append(c, '"');       /* t is >A~^`"< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(!term_char_equal(c, t));
+        c = term_char_merge(c, '"');            /* c is >A~^`"< now */
+        assert_se(!term_char_same(c, t));
+        assert_se(term_char_equal(c, t));
+
+        term_char_free(t);
+        term_char_free(c);
+}
+
+static void test_term_char_packing(void)  {
+        uint32_t seqs[][1024] = {
+                { -1 },
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+        };
+        term_char_t res[] = {
+                TERM_CHAR_NULL,
+                PACK1(0),
+                PACK2('A', '~'),
+                PACK3('A', '~', 0),
+                PACK3('A', '~', 'a'),
+        };
+        uint32_t next;
+        unsigned int i, j;
+        term_char_t c = TERM_CHAR_NULL;
+
+        /*
+         * This creates term_char_t objects based on the data in @seqs and
+         * compares the result to @res. Only basic packed types are tested, no
+         * allocations are done.
+         */
+
+        for (i = 0; i < ELEMENTSOF(seqs); ++i) {
+                for (j = 0; j < ELEMENTSOF(seqs[i]); ++j) {
+                        next = seqs[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        c = term_char_merge(c, next);
+                }
+
+                assert_se(!memcmp(&c, &res[i], sizeof(c)));
+                c = term_char_free(c);
+        }
+}
+
+static void test_term_char_allocating(void) {
+        uint32_t seqs[][1024] = {
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', 0, '^', -1 },
+                /* exceeding implementation-defined soft-limit of 64 */
+                { 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', -1 },
+        };
+        term_char_t res[] = {
+                PACK1(0),
+                PACK2('A', '~'),
+                PACK3('A', '~', 0),
+                PACK3('A', '~', 'a'),
+                TERM_CHAR_NULL,                 /* allocated */
+                TERM_CHAR_NULL,                 /* allocated */
+                TERM_CHAR_NULL,                 /* allocated */
+        };
+        uint32_t str[][1024] = {
+                { 0, -1 },
+                { 'A', '~', -1 },
+                { 'A', '~', 0, -1 },
+                { 'A', '~', 'a', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', -1 },
+                { 'A', '~', 'a', 'b', 'c', 'd', 0, '^', -1 },
+                { 'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd',
+                  'd', 'd', 'd', 'd', 'd', 'd', 'd', 'd', -1 },
+        };
+        size_t n;
+        uint32_t next;
+        unsigned int i, j;
+        const uint32_t *t;
+
+        /*
+         * This builds term_char_t objects based on the data in @seqs. It
+         * compares the result to @res for packed chars, otherwise it requires
+         * them to be allocated.
+         * After that, we resolve the UCS-4 string and compare it to the
+         * expected strings in @str.
+         */
+
+        for (i = 0; i < ELEMENTSOF(seqs); ++i) {
+                _term_char_free_ term_char_t c = TERM_CHAR_NULL;
+
+                for (j = 0; j < ELEMENTSOF(seqs[i]); ++j) {
+                        next = seqs[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        c = term_char_merge(c, next);
+                }
+
+                /* we use TERM_CHAR_NULL as marker for allocated chars here */
+                if (term_char_is_null(res[i]))
+                        assert_se(term_char_is_allocated(c));
+                else
+                        assert_se(!memcmp(&c, &res[i], sizeof(c)));
+
+                t = term_char_resolve(c, &n, NULL);
+                for (j = 0; j < ELEMENTSOF(str[i]); ++j) {
+                        next = str[i][j];
+                        if (next == (uint32_t)-1)
+                                break;
+
+                        assert_se(t[j] == next);
+                }
+
+                assert_se(n == j);
+        }
+}
+
+/*
+ * Line Tests
+ *
+ * The following tests work on term_line objects and verify their behavior when
+ * we modify them. To verify and set line layouts, we have two simple helpers
+ * to avoid harcoding the cell-verification all the time:
+ *   line_set(): Set a line to a given layout
+ *   line_assert(): Verify that a line has a given layout
+ *
+ * These functions take the line-layout encoded as a string and verify it
+ * against, or set it on, a term_line object. The format used to describe a
+ * line looks like this:
+ *       example: "|   | A |   |   |   |   |   | 10 *AB* |"
+ *
+ * The string describes the contents of all cells of a line, separated by
+ * pipe-symbols ('|'). Whitespace are ignored, the leading pipe-symbol is
+ * optional.
+ * The description of each cell can contain an arbitrary amount of characters
+ * in the range 'A'-'Z', 'a'-'z'. All those are combined and used as term_char_t
+ * on this cell. Any numbers in the description are combined and are used as
+ * cell-age.
+ * The occurance of a '*'-symbol marks the cell as bold, '/' marks it as italic.
+ * You can use those characters multiple times, but only the first one has an
+ * effect.
+ * For further symbols, see parse_attr().
+ *
+ * Therefore, the following descriptions are equivalent:
+ *       1) "|   | /A*   |   |   |   |   |   | 10 *AB*  |"
+ *       2) "|   | /A**  |   |   |   |   |   | 10 *AB*  |"
+ *       3) "|   | A* // |   |   |   |   |   | 10 *AB*  |"
+ *       4) "|   | A* // |   |   |   |   |   | 1 *AB* 0 |"
+ *       5) "|   | A* // |   |   |   |   |   | A1B0*    |"
+ *
+ * The parser isn't very strict about placement of alpha/numerical characters,
+ * but simply appends all found chars. Don't make use of that feature! It's
+ * just a stupid parser to simplify these tests. Make them readable!
+ */
+
+static void parse_attr(char c, term_char_t *ch, term_attr *attr, term_age_t *age) {
+        switch (c) {
+        case ' ':
+                /* ignore */
+                break;
+        case '0' ... '9':
+                /* increase age */
+                *age = *age * 10;
+                *age = *age + c - '0';
+                break;
+        case 'A' ... 'Z':
+        case 'a' ... 'z':
+                /* add to character */
+                *ch = term_char_merge(*ch, c);
+                break;
+        case '*':
+                attr->bold = true;
+                break;
+        case '/':
+                attr->italic = true;
+                break;
+        default:
+                assert_se(0);
+                break;
+        }
+}
+
+static void cell_assert(MY_ASSERT_ARGS, term_cell *c, term_char_t ch, const term_attr *attr, term_age_t age) {
+        MY_ASSERT(term_char_equal(c->ch, ch));
+        MY_ASSERT(!memcmp(&c->attr, attr, sizeof(*attr)));
+        MY_ASSERT(c->age == age);
+}
+#define CELL_ASSERT(_cell, _ch, _attr, _age) cell_assert(MY_ASSERT_VALS, (_cell), (_ch), (_attr), (_age))
+
+static void line_assert(MY_ASSERT_ARGS, term_line *l, const char *str, unsigned int fill) {
+        unsigned int cell_i;
+        term_char_t ch = TERM_CHAR_NULL;
+        term_attr attr = { };
+        term_age_t age = TERM_AGE_NULL;
+        char c;
+
+        assert_se(l->fill == fill);
+
+        /* skip leading whitespace */
+        while (*str == ' ')
+                ++str;
+
+        /* skip leading '|' */
+        if (*str == '|')
+                ++str;
+
+        cell_i = 0;
+        while ((c = *str++)) {
+                switch (c) {
+                case '|':
+                        /* end of cell-description; compare it */
+                        assert_se(cell_i < l->n_cells);
+                        cell_assert(MY_ASSERT_FORW,
+                                    &l->cells[cell_i],
+                                    ch,
+                                    &attr,
+                                    age);
+
+                        ++cell_i;
+                        ch = term_char_free(ch);
+                        zero(attr);
+                        age = TERM_AGE_NULL;
+                        break;
+                default:
+                        parse_attr(c, &ch, &attr, &age);
+                        break;
+                }
+        }
+
+        assert_se(cell_i == l->n_cells);
+}
+#define LINE_ASSERT(_line, _str, _fill) line_assert(MY_ASSERT_VALS, (_line), (_str), (_fill))
+
+static void line_set(term_line *l, unsigned int pos, const char *str, bool insert_mode) {
+        term_char_t ch = TERM_CHAR_NULL;
+        term_attr attr = { };
+        term_age_t age = TERM_AGE_NULL;
+        char c;
+
+        while ((c = *str++))
+                parse_attr(c, &ch, &attr, &age);
+
+        term_line_write(l, pos, ch, 1, &attr, age, insert_mode);
+}
+
+static void line_resize(term_line *l, unsigned int width, const term_attr *attr, term_age_t age) {
+        assert_se(term_line_reserve(l, width, attr, age, width) >= 0);
+        term_line_set_width(l, width);
+}
+
+static void test_term_line_misc(void) {
+        term_line *l;
+
+        assert_se(term_line_new(&l) >= 0);
+        assert_se(!term_line_free(l));
+
+        assert_se(term_line_new(NULL) < 0);
+        assert_se(!term_line_free(NULL));
+
+        assert_se(term_line_new(&l) >= 0);
+        assert_se(l->n_cells == 0);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 16, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 16);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 512, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 512);
+        assert_se(l->fill == 0);
+        assert_se(term_line_reserve(l, 16, NULL, 0, 0) >= 0);
+        assert_se(l->n_cells == 512);
+        assert_se(l->fill == 0);
+        assert_se(!term_line_free(l));
+}
+
+static void test_term_line_ops(void) {
+        term_line *l;
+        term_attr attr_regular = { };
+        term_attr attr_bold = { .bold = true };
+        term_attr attr_italic = { .italic = true };
+
+        assert_se(term_line_new(&l) >= 0);
+        line_resize(l, 8, NULL, 0);
+        assert_se(l->n_cells == 8);
+
+        LINE_ASSERT(l, "| | | | | | | | |", 0);
+
+        term_line_write(l, 4, TERM_CHAR_NULL, 0, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| | | | | | | | |", 5);
+
+        term_line_write(l, 1, PACK1('A'), 1, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| |A| | | | | | |", 5);
+
+        term_line_write(l, 8, PACK2('A', 'B'), 1, NULL, TERM_AGE_NULL, 0);
+        LINE_ASSERT(l, "| |A| | | | | | |", 5);
+
+        term_line_write(l, 7, PACK2('A', 'B'), 1, &attr_regular, 10, 0);
+        LINE_ASSERT(l, "| |A| | | | | | 10 AB |", 8);
+
+        term_line_write(l, 7, PACK2('A', 'B'), 1, &attr_bold, 10, 0);
+        LINE_ASSERT(l, "| |A| | | | | | 10 *AB* |", 8);
+
+        term_line_reset(l, NULL, TERM_AGE_NULL);
+
+        LINE_ASSERT(l, "|   |   |          |          |          |   |   |   |", 0);
+        line_set(l, 2, "*wxyz* 8", 0);
+        line_set(l, 3, "/wxyz/ 8", 0);
+        LINE_ASSERT(l, "|   |   | *wxyz* 8 | /wxyz/ 8 |          |   |   |   |", 4);
+        line_set(l, 2, "*abc* 9", true);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 9 | 9 |", 5);
+        line_set(l, 7, "*abc* 10", true);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 9 | *abc* 10 |", 8);
+
+        term_line_erase(l, 6, 1, NULL, 11, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 11 | *abc* 10 |", 8);
+        term_line_erase(l, 6, 2, &attr_italic, 12, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 12 // | 12 // |", 6);
+        term_line_erase(l, 7, 2, &attr_regular, 13, 0);
+        LINE_ASSERT(l, "|   |   | *abc* 9  | *wxyz* 9 | /wxyz/ 9 | 9 | 12 // | 13 |", 6);
+        term_line_delete(l, 1, 3, &attr_bold, 14);
+        LINE_ASSERT(l, "|   | /wxyz/ 14 | 14 | 14 // | 14 | 14 ** | 14 ** | 14 ** |", 3);
+        term_line_insert(l, 2, 2, &attr_regular, 15);
+        LINE_ASSERT(l, "|   | /wxyz/ 14 | 15 | 15 | 15 | 15 // | 15 | 15 ** |", 5);
+
+        assert_se(!term_line_free(l));
+}
+
+int main(int argc, char *argv[]) {
+        test_term_char_misc();
+        test_term_char_packing();
+        test_term_char_allocating();
+
+        test_term_line_misc();
+        test_term_line_ops();
+
+        return 0;
+}

commit 3496b9eeafa50234371da1642dca424e4ca0e5f4
Author: David Herrmann <dh.herrmann at gmail.com>
Date:   Thu Jul 17 11:48:03 2014 +0200

    nspawn: fix barrier-destroy call
    
    I dropped the cleanup-helper before pushing so use _cleanup_() directly.

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index e75cc28..657512d 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -3073,7 +3073,7 @@ int main(int argc, char *argv[]) {
 
         for (;;) {
                 ContainerStatus container_status;
-                _barrier_destroy_ Barrier barrier = { };
+                _cleanup_(barrier_destroy) Barrier barrier = { };
                 struct sigaction sa = {
                         .sa_handler = nop_handler,
                         .sa_flags = SA_NOCLDSTOP,



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