updated for version 7.3.376
Problem:    Win32: Toolbar repainting does not work when the mouse pointer
            hovers over a button.
Solution:   Call DefWindowProc() when not hanlding an event. (Sergiu Dotenco)
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 4a34cb4..c36f73d 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -1101,7 +1101,7 @@
 	return MyWindowProc(hwnd, uMsg, wParam, lParam);
     }
 
-    return 1;
+    return DefWindowProc(hwnd, uMsg, wParam, lParam);
 }
 
 /*