Subject: Toggle autostrafe for the keyboard when both Alt keys are pressed.
 By the way, accept the German AltGr key as a right Alt key.
Author: Fabian Greffrath <fabian+debian@greffrath.com>

--- a/id_in.cpp
+++ b/id_in.cpp
@@ -239,6 +239,7 @@ boolean IN_JoyPresent()
 
 boolean mw_dn = false, mw_up = false;
 boolean autorun = false;
+boolean autostrafe = false;
 
 static void processEvent(SDL_Event *event)
 {
@@ -272,6 +273,19 @@ static void processEvent(SDL_Event *even
                 IN_ClearKeysDown ();
                 IN_Ack ();
             }
+            if (((mod & KMOD_LALT) && (mod & KMOD_RALT)) ||
+                ((mod & KMOD_LALT) && (mod & KMOD_MODE)))
+            {
+                autostrafe = !autostrafe;
+
+                if (autostrafe)
+                    Message ("Always Strafe: On");
+                else
+                    Message ("Always Strafe: Off");
+
+                IN_ClearKeysDown ();
+                IN_Ack ();
+            }
 
             if(Keyboard[sc_Alt])
             {
@@ -282,6 +296,7 @@ static void processEvent(SDL_Event *even
             if(LastScan == SDLK_KP_ENTER) LastScan = SDLK_RETURN;
             else if(LastScan == SDLK_RSHIFT) LastScan = SDLK_LSHIFT;
             else if(LastScan == SDLK_RALT) LastScan = SDLK_LALT;
+            else if(LastScan == SDLK_MODE) LastScan = SDLK_LALT; /* AltGr */
             else if(LastScan == SDLK_RCTRL) LastScan = SDLK_LCTRL;
             else
             {
@@ -324,6 +339,7 @@ static void processEvent(SDL_Event *even
             if(key == SDLK_KP_ENTER) key = SDLK_RETURN;
             else if(key == SDLK_RSHIFT) key = SDLK_LSHIFT;
             else if(key == SDLK_RALT) key = SDLK_LALT;
+            else if(key == SDLK_MODE) key = SDLK_LALT; /* AltGr */
             else if(key == SDLK_RCTRL) key = SDLK_LCTRL;
             else
             {
--- a/wl_play.cpp
+++ b/wl_play.cpp
@@ -331,15 +331,26 @@ void PollJoystickButtons (void)
 void PollKeyboardMove (void)
 {
     int delta = buttonstate[bt_run] ? RUNMOVE * tics : BASEMOVE * tics;
+    extern boolean autostrafe;
 
     if (Keyboard[dirscan[di_north]])
         controly -= delta;
     if (Keyboard[dirscan[di_south]])
         controly += delta;
     if (Keyboard[dirscan[di_west]])
-        controlx -= delta;
+    {
+        if (autostrafe)
+            buttonstate[bt_strafeleft] = true;
+        else
+            controlx -= delta;
+    }
     if (Keyboard[dirscan[di_east]])
-        controlx += delta;
+    {
+        if (autostrafe)
+            buttonstate[bt_straferight] = true;
+        else
+            controlx += delta;
+    }
 }