comctl32: Don't update rebar layout if it doesn't change in REBAR_HandleUDDrag.

dlls/comctl32/rebar.c

@@ -2136,6 +2136,8 @@ REBAR_HandleUDDrag (REBAR_INFO *infoPtr, const POINT *ptsmove)
     if(yOff < 0)
     {
         /* Place the band above the current top row */
+        if(iHitBand==0 && (infoPtr->uNumBands==1 || REBAR_GetBand(infoPtr, 1)->fStyle&RBBS_BREAK))
+            return;
         DPA_DeletePtr(infoPtr->bands, iHitBand);
         hitBand->fStyle &= RBBS_BREAK;
         REBAR_GetBand(infoPtr, 0)->fStyle |= RBBS_BREAK;
@@ -2145,6 +2147,8 @@ REBAR_HandleUDDrag (REBAR_INFO *infoPtr, const POINT *ptsmove)
     else if(yOff > REBAR_GetBand(infoPtr, infoPtr->uNumBands - 1)->rcBand.bottom)
     {
         /* Place the band below the current bottom row */
+        if(iHitBand == infoPtr->uNumBands-1 && hitBand->fStyle&RBBS_BREAK)
+            return;
         DPA_DeletePtr(infoPtr->bands, iHitBand);
         hitBand->fStyle |= RBBS_BREAK;
         infoPtr->iGrabbedBand = DPA_InsertPtr(