A (hopefully) better fix for bug #1280.

 src/w32fns.c (modifier_set): Don't report modifiers from toggle key,
 such as Scroll Lock, if the respective keys are treated as
 function keys, not as modifiers.  This avoids destroying non-ASCII
 keyboard input when Scroll Lock is toggled ON.

2 files changed, 31 insertions, 21 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c1b42e276c5..04b66ba7cc7 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,10 +1,9 @@
 2012-11-07  Eli Zaretskii  <eliz@gnu.org>
 
-        * w32fns.c (w32_wnd_proc): Don't directly handle key chords
-        including modifiers from toggle key, such as Scroll Lock, if the
-        respective keys are treated as function keys, not as modifiers.
-        This avoids destroying non-ASCII keyboard input when Scroll Lock
-        is toggled ON.  (Bug#1280)
+        * w32fns.c (modifier_set): Don't report modifiers from toggle key,
+        such as Scroll Lock, if the respective keys are treated as
+        function keys, not as modifiers.  This avoids destroying non-ASCII
+        keyboard input when Scroll Lock is toggled ON.  (Bug#1280)
         (modifier_set): Do not omit checking the Num Lock key.
 
 2012-11-07  Dmitry Antipov  <dmantipov@yandex.ru>
diff --git a/src/w32fns.c b/src/w32fns.c
index dc395551a4a..b5e717f8980 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -2085,8 +2085,28 @@ sync_modifiers (void)
 static int
 modifier_set (int vkey)
 {
-  if (vkey == VK_CAPITAL || vkey == VK_SCROLL || vkey == VK_NUMLOCK)
-    return (GetKeyState (vkey) & 0x1);
+  if (vkey == VK_CAPITAL)
+    {
+      if (NILP (Vw32_enable_caps_lock))
+        return 0;
+      else
+        return (GetKeyState (vkey) & 0x1);
+    }
+  if (vkey == VK_SCROLL)
+    {
+      if (NILP (Vw32_scroll_lock_modifier))
+        return 0;
+      else
+        return (GetKeyState (vkey) & 0x1);
+    }
+  if (vkey == VK_NUMLOCK)
+    {
+      if (NILP (Vw32_enable_num_lock))
+        return 0;
+      else
+        return (GetKeyState (vkey) & 0x1);
+    }
+
   if (!modifiers_recorded)
     return (GetKeyState (vkey) & 0x8000);
 
@@ -2974,21 +2994,12 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
             {
               DWORD modifiers = construct_console_modifiers ();
 
-              /* Always let TranslateMessage handle AltGr key chords;
-                 for some reason, ToAscii doesn't always process AltGr
-                 chords correctly.  */
-              if ((!NILP (Vw32_recognize_altgr)
-                   && modifier_set (VK_LCONTROL) && modifier_set (VK_RMENU))
-                  /* If a toggle key is used as a function key, let
-                     TranslateMessage handle keys pressed while the
-                     toggled key is ON.  This avoids munging non-ASCII
-                     keys, like interpreting them as ASCII keys below,
-                     when, e.g., Scroll Lock is toggled ON.  */
-                  || (NILP (Vw32_scroll_lock_modifier)
-                      && modifier_set (VK_SCROLL))
-                  || (NILP (Vw32_enable_num_lock) && modifier_set (VK_NUMLOCK))
-                  || (NILP (Vw32_enable_caps_lock) && modifier_set (VK_CAPITAL)))
+              if (!NILP (Vw32_recognize_altgr)
+                  && modifier_set (VK_LCONTROL) && modifier_set (VK_RMENU))
                 {
+                  /* Always let TranslateMessage handle AltGr key chords;
+                     for some reason, ToAscii doesn't always process AltGr
+                     chords correctly.  */
                   windows_translate = 1;
                 }
               else if ((modifiers & (~SHIFT_PRESSED & ~CAPSLOCK_ON)) != 0)