[Bugfix] Fix "Alt key gets stuck in Xvnc" issue.

Reference:
http://www.mail-archive.com/tigervnc-users@lists.sourceforge.net/msg00196.html

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4236 3789f03b-4d11-0410-bbf8-ca57d06f2519

diff --git a/unix/xserver/hw/vnc/Input.cc b/unix/xserver/hw/vnc/Input.cc
index dd1cfb86685301909f8eb4fe550087a4e41225d4..ca9bae3efba7843b65ed896bb3736ab9e9c2dbc5 100644 (file)
--- a/unix/xserver/hw/vnc/Input.cc
+++ b/unix/xserver/hw/vnc/Input.cc
@@ -520,6 +520,49 @@ static struct altKeysym_t {
 #define FREE_MAPS
 #endif
 
+#if XORG >= 17
+/*
+ * Modifier keysyms must be handled differently. Instead of finding
+ * the right row and collumn in the keymap, directly press/release
+ * the keycode which is mapped as modifier with the same keysym.
+ *
+ * This will avoid issues when there are multiple modifier keysyms
+ * in the keymap but only some of them are mapped as modifiers in
+ * the modmap.
+ *
+ * Returns keycode of the modifier key.
+ */
+
+static inline int isModifier(KeySymsPtr keymap, KeyCode *modmap,
+                             int maxKeysPerMod, rdr::U32 keysym)
+{
+       KeySym *map = keymap->map;
+       KeyCode minKeyCode = keymap->minKeyCode;
+       int mapWidth = keymap->mapWidth;
+       int i, j, k;
+
+       /* Find modifier index in the modmap */
+       for (i = 0; i < 8; i++) {
+               for (k = 0; k < maxKeysPerMod; k++) {
+                       int index = i * maxKeysPerMod + k;
+                       int keycode = modmap[index];
+
+                       if (keycode == 0)
+                               continue;
+
+                       for (j = 0; j < mapWidth; j++) {
+                               if (map[(keycode - minKeyCode) * mapWidth + j]
+                                   == keysym) {
+                                       return keycode;
+                               }
+                       }
+               }
+       }
+
+       return -1; /* Not a modifier */
+}
+#endif
+
 void InputDevice::keyEvent(rdr::U32 keysym, bool down)
 {
 #if XORG < 17
@@ -618,7 +661,26 @@ void InputDevice::keyEvent(rdr::U32 keysym, bool down)
        }
 ModeSwitchFound:
 
+       int kc;
        int col = 0;
+
+#if XORG >= 17
+       if ((kc = isModifier(keymap, modmap, maxKeysPerMod, keysym)) != -1) {
+               /*
+                * It is a modifier key event.
+                *
+                * Don't do any auto-repeat because the X server will translate
+                * each press into a release followed by a press.
+                */
+               if (IS_PRESSED(keyc, kc) && down) {
+                       FREE_MAPS;
+                       return;
+               }
+
+               goto press;
+       }
+#endif
+
        if (maxKeysPerMod != 0) {
                if ((state & (1 << ShiftMapIndex)) != 0)
                        col |= 1;
@@ -627,7 +689,7 @@ ModeSwitchFound:
                        col |= 2;
        }
 
-       int kc = KeysymToKeycode(keymap, keysym, &col);
+       kc = KeysymToKeycode(keymap, keysym, &col);
 
        /*
         * Sort out the "shifted Tab" mess.  If we are sent a shifted Tab,
@@ -704,6 +766,7 @@ ModeSwitchFound:
                return;
        }
 
+#if XORG < 17
        /*
         * See if it's a modifier key.  If so, then don't do any auto-repeat,
         * because the X server will translate each press into a release
@@ -718,6 +781,7 @@ ModeSwitchFound:
                        }       
                }
        }
+#endif
 
        if (maxKeysPerMod != 0) {
                ModifierState shift(keyboardDev, ShiftMapIndex);
@@ -739,8 +803,10 @@ ModeSwitchFound:
                 * pressKey call, otherwise fake modifier keypress can be lost.
                 */
                pressKey(keyboardDev, kc, down, "keycode");
-       } else
+       } else {
+press:
                pressKey(keyboardDev, kc, down, "keycode");
+       }
 
 
         FREE_MAPS;