[Spice-devel] [spice-gtk v2] widget: Do not ignore unsupported keys from keyboard

[Frediano Ziglio]

If Windows layout does not support a given key the resulting virtual code
is set to 0xFF. To avoid losing this raw key (causing the key not been
sent to remote machine) detect this condition and handle the key.
The check for raw scancode is there to understand if we can handle
correctly the key in following code.
This problem can happen for instance using a 106 key Japanese keyboard
while the layout is set in English; in this case keys like CONVERT not
forwarded correctly.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 src/spice-widget.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

Changes from v1:
- avoid to rewrite scancodes;
- tested again (code were not used as my mingw64-gtk3 was updated
  and gdk_event_get_scancode was not supported).

diff --git a/src/spice-widget.c b/src/spice-widget.c
index 51a2055..b5936bc 100644
--- a/src/spice-widget.c
+++ b/src/spice-widget.c
@@ -1406,7 +1406,7 @@ static gboolean key_event(GtkWidget *widget, GdkEventKey *key)
 {
     SpiceDisplay *display = SPICE_DISPLAY(widget);
     SpiceDisplayPrivate *d = display->priv;
-    int scancode;
+    int scancode = 0;
 #ifdef G_OS_WIN32
     int native_scancode;
     WORD langid = LOWORD(GetKeyboardLayout(0));
@@ -1414,8 +1414,23 @@ static gboolean key_event(GtkWidget *widget, GdkEventKey *key)
 #endif
 
 #ifdef G_OS_WIN32
+    /* Try to get scancode with gdk_event_get_scancode.
+     * This API is available from 3.22 or if backported.
+     */
+#if HAVE_GDK_EVENT_GET_SCANCODE
+    native_scancode = gdk_event_get_scancode((GdkEvent *) key);
+    if (native_scancode) {
+        scancode = native_scancode & 0x1ff;
+        /* Windows always set extended attribute for these keys */
+        if (scancode == (0x100|DIK_NUMLOCK) || scancode == (0x100|DIK_RSHIFT))
+            scancode &= 0xff;
+    }
+#else
+    native_scancode = 0;
+#endif
+
     /* on windows, we ought to ignore the reserved key event? */
-    if (key->hardware_keycode == 0xff)
+    if (!native_scancode && key->hardware_keycode == 0xff)
         return false;
 
     if (!d->keyboard_grab_active) {
@@ -1455,23 +1470,10 @@ static gboolean key_event(GtkWidget *widget, GdkEventKey *key)
     if (!d->inputs)
         return true;
 
-    scancode = vnc_display_keymap_gdk2xtkbd(d->keycode_map, d->keycode_maplen,
-                                            key->hardware_keycode);
+    if (!scancode)
+        scancode = vnc_display_keymap_gdk2xtkbd(d->keycode_map, d->keycode_maplen,
+                                                key->hardware_keycode);
 #ifdef G_OS_WIN32
-    /* Try to get scancode with gdk_event_get_scancode.
-     * This API is available from 3.22 or if backported.
-     */
-#if HAVE_GDK_EVENT_GET_SCANCODE
-    native_scancode = gdk_event_get_scancode((GdkEvent *) key);
-    if (native_scancode) {
-        scancode = native_scancode & 0x1ff;
-        /* Windows always set extended attribute for these keys */
-        if (scancode == (0x100|DIK_NUMLOCK) || scancode == (0x100|DIK_RSHIFT))
-            scancode &= 0xff;
-    }
-#else
-    native_scancode = 0;
-#endif
     if (!native_scancode) {
         native_scancode = MapVirtualKey(key->hardware_keycode, MAPVK_VK_TO_VSC);
         /* MapVirtualKey doesn't return scancode with needed higher byte */
-- 
2.7.4