#94150

r=mkaply, a=blizzard
Code from aaronr - return proper class for scrollbar

widget/src/os2/nsScrollbar.cpp

@@ -326,7 +326,12 @@ PRBool nsScrollbar::OnScroll( ULONG msgid, MPARAM mp1, MPARAM mp2)
 //-------------------------------------------------------------------------
 PCSZ nsScrollbar::WindowClass()
 {
-    return WC_SCROLLBAR;
+    /* Can't return (PSZ)WC_SCROLLBAR since we need to return a real string
+     * as some string manipulation might be done on the returned value.
+     * The return from WinQueryClassName for a WC_SCROLLBAR is "#8", so that is
+     * what we'll return.  Value makes since since WC_SCROLLBAR is 0xFFFF0008.
+     */
+    return WC_SCROLLBAR_STRING;
 }
 
 

widget/src/os2/nsWindow.cpp

@@ -802,6 +802,7 @@ void nsWindow::RealDoCreate( HWND              hwndP,
 
    if( hwndP != HWND_DESKTOP)
    {
+
       // For pop-up menus, the parent is the desktop, but use the "parent" as owner
       if( aInitData && aInitData->mWindowType == eWindowType_popup)
       {
@@ -812,9 +813,14 @@ void nsWindow::RealDoCreate( HWND              hwndP,
          hwndP = HWND_DESKTOP;
       }
       // For scrollbars, the parent is the owner, for notification purposes
-      else if( !hwndOwner && WindowClass() == WC_SCROLLBAR)
+      else if( !hwndOwner )
       {
-         hwndOwner = hwndP;
+         BOOL bHwndIsScrollBar = 
+                           (!(strcmp( WindowClass(), WC_SCROLLBAR_STRING )));
+         if( bHwndIsScrollBar )
+         {
+            hwndOwner = hwndP;
+         }
       }
    }
 

widget/src/os2/nsdefs.h

@@ -40,6 +40,8 @@
   #define VERIFY(exp)                 (exp)
 #endif  // !_DEBUG
 
+#define WC_SCROLLBAR_STRING    "#8"  //string equivalent to WC_SCROLLBAR
+
 #endif  // NSDEFS_H