master 15910e5da3: Ignore modifier keys early when handling X key press events

[Po Lu]

branch: master
commit 15910e5da34a084fe01e0fd96ecf394cb1030e25
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Ignore modifier keys early when handling X key press events
    
    * src/xterm.c (handle_one_xevent): Ignore modifier keys earlier
    without going through the usual key lookup.
    (x_delete_terminal): Free recorded modifier map.
    (x_find_modifier_meanings): Record modifier map.
    
    * src/xterm.h (struct x_display_info): New field `modmap'.
---
 src/xterm.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/xterm.h |  3 +++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/src/xterm.c b/src/xterm.c
index 64bee11022..4c1c431217 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -6162,7 +6162,10 @@ x_find_modifier_meanings (struct x_display_info *dpyinfo)
     dpyinfo->hyper_mod_mask &= ~dpyinfo->super_mod_mask;
 
   XFree (syms);
-  XFreeModifiermap (mods);
+
+  if (dpyinfo->modmap)
+    XFreeModifiermap (dpyinfo->modmap);
+  dpyinfo->modmap = mods;
 }
 
 /* Convert between the modifier bits X uses and the modifier bits
@@ -9893,6 +9896,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
          /* `xkey' will be modified, but it's not important to modify
             `event' itself.  */
          XKeyEvent xkey = event->xkey;
+         int i;
 
 #ifdef USE_GTK
           /* Don't pass keys to GTK.  A Tab will shift focus to the
@@ -9924,6 +9928,27 @@ handle_one_xevent (struct x_display_info *dpyinfo,
           if (modifiers & dpyinfo->meta_mod_mask)
             memset (&compose_status, 0, sizeof (compose_status));
 
+#ifdef HAVE_XKB
+         if (FRAME_DISPLAY_INFO (f)->xkb_desc)
+           {
+             XkbDescRec *rec = FRAME_DISPLAY_INFO (f)->xkb_desc;
+
+             if (rec->map->modmap && rec->map->modmap[xkey.keycode])
+               goto done_keysym;
+           }
+         else
+#endif
+           {
+             if (dpyinfo->modmap)
+               {
+                 for (i = 0; i < 8 * dpyinfo->modmap->max_keypermod; i++)
+                   {
+                     if (xkey.keycode == dpyinfo->modmap->modifiermap[i])
+                         goto done_keysym;
+                   }
+               }
+           }
+
 #ifdef HAVE_X_I18N
           if (FRAME_XIC (f))
             {
@@ -11545,6 +11570,27 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                }
 #endif
 
+#ifdef HAVE_XKB
+             if (FRAME_DISPLAY_INFO (f)->xkb_desc)
+               {
+                 XkbDescRec *rec = FRAME_DISPLAY_INFO (f)->xkb_desc;
+
+                 if (rec->map->modmap && rec->map->modmap[xev->detail])
+                   goto done_keysym;
+               }
+             else
+#endif
+               {
+                 if (dpyinfo->modmap)
+                   {
+                     for (i = 0; i < 8 * dpyinfo->modmap->max_keypermod; i++)
+                       {
+                         if (xkey.keycode == 
dpyinfo->modmap->modifiermap[xev->detail])
+                           goto done_keysym;
+                       }
+                   }
+               }
+
 #ifdef HAVE_XKB
              if (dpyinfo->xkb_desc)
                {
@@ -16743,6 +16789,9 @@ x_delete_terminal (struct terminal *terminal)
       XCloseDisplay (dpyinfo->display);
 #endif
 #endif /* ! USE_GTK */
+
+      if (dpyinfo->modmap)
+       XFreeModifiermap (dpyinfo->modmap);
       /* Do not close the connection here because it's already closed
         by X(t)CloseDisplay (Bug#18403).  */
       dpyinfo->display = NULL;
diff --git a/src/xterm.h b/src/xterm.h
index f58fa0fe54..14457b32cc 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -526,6 +526,9 @@ struct x_display_info
   Atom Xatom_Meta, Xatom_Super, Xatom_Hyper, Xatom_ShiftLock, Xatom_Alt;
 #endif
 
+  /* Core modifier map when XKB is not present.  */
+  XModifierKeymap *modmap;
+
 #ifdef HAVE_XRANDR
   int xrandr_major_version;
   int xrandr_minor_version;