diff -bu src/nsfont.m src/nsfont.m
--- src/nsfont.m	2012-01-17 13:11:13.000000000 +0900
+++ src/nsfont.m	2012-01-17 13:03:43.000000000 +0900
@@ -1286,7 +1286,7 @@
       }
 
     CGContextRestoreGState (gcontext);
-    return;
+    return YES;
   }
 #endif  /* NS_IMPL_COCOA */
 
diff -bu src/nsimage.m src/nsimage.m
--- src/nsimage.m	2012-01-17 13:10:02.000000000 +0900
+++ src/nsimage.m	2012-01-17 12:59:32.000000000 +0900
@@ -334,7 +334,7 @@
   NSColor *rgbColor;
 
   if (bmRep == nil || color == nil)
-    return;
+    return YES;
 
   if ([color colorSpaceName] != NSCalibratedRGBColorSpace)
     rgbColor = [color colorUsingColorSpaceName: NSCalibratedRGBColorSpace];
diff -bu src/nsterm.m src/nsterm.m
--- src/nsterm.m	2012-01-17 13:11:15.000000000 +0900
+++ src/nsterm.m	2012-01-17 12:58:35.000000000 +0900
@@ -5481,7 +5481,7 @@
   NSTRACE (performDragOperation);
 
   if (!emacs_event)
-    return;
+    return YES;
 
   position = [self convertPoint: [sender draggingLocation] fromView: nil];
   x = lrint (position.x);  y = lrint (position.y);