[Xcb] [PATCH libxcb] Introduce new funcion xcb_connect_with_auth_file().

[Laércio de Sousa]

This patch introduces a function called xcb_connect_with_auth_file(),
which is similar to xcb_connect_to_display_with_auth_info(), but expects
an authorization file path rather than a xcb_auth_info_t struct.

Signed-off-by: Laércio de Sousa <laerciosousa at sme-mogidascruzes.sp.gov.br>
---
 src/xcb.h      | 21 +++++++++++++++++++++
 src/xcb_auth.c | 15 +++++++++++++--
 src/xcb_util.c | 27 ++++++++++++++++++++-------
 src/xcbint.h   |  2 +-
 4 files changed, 55 insertions(+), 10 deletions(-)

diff --git a/src/xcb.h b/src/xcb.h
index 23fe74e..0314ce5 100644
--- a/src/xcb.h
+++ b/src/xcb.h
@@ -535,6 +535,27 @@ int xcb_parse_display(const char *name, char **host, int *display, int *screen);
 xcb_connection_t *xcb_connect(const char *displayname, int *screenp);
 
 /**
+ * @brief Connects to the X server, using and authorization file.
+ * @param displayname: The name of the display.
+ * @param authfile: The authorization file path.
+ * @param screenp: A pointer to a preferred screen number.
+ * @return A newly allocated xcb_connection_t structure.
+ *
+ * Connects to the X server specified by @p displayname, using the
+ * authorization file @p authfile. If @p authfile value @c NULL, uses
+ * the value of the XAUTHORITY environment variable. If a particular
+ * screen on that server is preferred, the int pointed to by @p screenp
+ * (if not @c NULL) will be set to that screen; otherwise @p screenp
+ * will be set to 0.
+ *
+ * Always returns a non-NULL pointer to a xcb_connection_t, even on failure.
+ * Callers need to use xcb_connection_has_error() to check for failure.
+ * When finished, use xcb_disconnect() to close the connection and free
+ * the structure.
+ */
+xcb_connection_t *xcb_connect_with_auth_file(const char *displayname, const char *authfile, int *screenp);
+
+/**
  * @brief Connects to the X server, using an authorization information.
  * @param display: The name of the display.
  * @param auth: The authorization information.
diff --git a/src/xcb_auth.c b/src/xcb_auth.c
index 29e2b6f..284a582 100644
--- a/src/xcb_auth.c
+++ b/src/xcb_auth.c
@@ -34,6 +34,7 @@
 #include <sys/param.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <stdio.h>
 
 #ifdef __INTERIX
 /* _don't_ ask. interix has INADDR_LOOPBACK in here. */
@@ -309,7 +310,7 @@ static struct sockaddr *get_peer_sock_name(int (*socket_func)(int,
     return NULL;
 }
 
-int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display)
+int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display, const char *authfile)
 {
     /* code adapted from Xlib/ConnDis.c, xtrans/Xtranssocket.c,
        xtrans/Xtransutils.c */
@@ -334,7 +335,17 @@ int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display)
         gotsockname = 1;
     }
 
-    authptr = get_authptr(sockname, display);
+    if (authfile) {
+        FILE *f = fopen(authfile, "r");
+
+        if (f) {
+            authptr = XauReadAuth(f);
+            fclose(f);
+        }
+    }
+    else
+        authptr = get_authptr(sockname, display);
+
     if (authptr == 0)
     {
         free(sockname);
diff --git a/src/xcb_util.c b/src/xcb_util.c
index ba0f108..aafb73d 100644
--- a/src/xcb_util.c
+++ b/src/xcb_util.c
@@ -475,12 +475,10 @@ static int _xcb_open_abstract(char *protocol, const char *file, size_t filelen)
 }
 #endif
 
-xcb_connection_t *xcb_connect(const char *displayname, int *screenp)
-{
-    return xcb_connect_to_display_with_auth_info(displayname, NULL, screenp);
-}
-
-xcb_connection_t *xcb_connect_to_display_with_auth_info(const char *displayname, xcb_auth_info_t *auth, int *screenp)
+static xcb_connection_t *_xcb_connect_to_display_with_auth_info_or_file(const char *displayname,
+                                                                        const char *authfile,
+                                                                        xcb_auth_info_t *auth,
+                                                                        int *screenp)
 {
     int fd, display = 0;
     char *host = NULL;
@@ -518,7 +516,7 @@ xcb_connection_t *xcb_connect_to_display_with_auth_info(const char *displayname,
         goto out;
     }
 
-    if(_xcb_get_auth_info(fd, &ourauth, display))
+    if(_xcb_get_auth_info(fd, &ourauth, display, authfile))
     {
         c = xcb_connect_to_fd(fd, &ourauth);
         free(ourauth.name);
@@ -542,3 +540,18 @@ out:
     free(protocol);
     return c;
 }
+
+xcb_connection_t *xcb_connect(const char *displayname, int *screenp)
+{
+    return xcb_connect_to_display_with_auth_info(displayname, NULL, screenp);
+}
+
+xcb_connection_t *xcb_connect_with_auth_file(const char *displayname, const char *authfile, int *screenp)
+{
+    return _xcb_connect_to_display_with_auth_info_or_file(displayname, authfile, NULL, screenp);
+}
+
+xcb_connection_t *xcb_connect_to_display_with_auth_info(const char *displayname, xcb_auth_info_t *auth, int *screenp)
+{
+    return _xcb_connect_to_display_with_auth_info_or_file(displayname, NULL, auth, screenp);
+}
diff --git a/src/xcbint.h b/src/xcbint.h
index f89deba..01aca8c 100644
--- a/src/xcbint.h
+++ b/src/xcbint.h
@@ -218,7 +218,7 @@ int _xcb_conn_wait(xcb_connection_t *c, pthread_cond_t *cond, struct iovec **vec
 
 /* xcb_auth.c */
 
-int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display);
+int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display, const char *authfile);
 
 #ifdef GCC_HAS_VISIBILITY
 #pragma GCC visibility pop
-- 
1.8.4.5