Bug 153470

Use IsDBCSLeadByteEx() instead of IsDBCSLeadByte()
to allow specifying the current IME code point.
IME input method improvement
/r=shanjian;/sr=kin

widget/src/windows/nsWindow.cpp

@@ -2967,7 +2967,7 @@ BOOL nsWindow::OnChar( UINT mbcsCharCode, UINT virtualKeyCode, bool isMultiByte
       } 
       else {
         charToConvert[0] = LOBYTE(mbcsCharCode);
-        if (::IsDBCSLeadByte(charToConvert[0])) {
+        if (::IsDBCSLeadByteEx(gCurrentKeyboardCP, charToConvert[0])) {
           mLeadByte = charToConvert[0];
           return TRUE;
         }