diff --git a/commands/CmdCD.c b/commands/CmdCD.c
index 5d71580d..2eec220e 100644
--- a/commands/CmdCD.c
+++ b/commands/CmdCD.c
@@ -3955,6 +3955,9 @@ int cmdDropPaintCell(tile, cxp)
 
     TiToRect(tile, &area);
 
+    /* Clip to search area */
+    GEOCLIP(&area, &cxp->tc_scx->scx_area);
+
     DBPaintMask(cellDef, &area, lMask);
 
     return 0;
@@ -4078,6 +4081,7 @@ CmdDrop(w, cmd)
     TileTypeBitMask lMask, tMask;
     CellUse *checkUse;
     int pNum;
+    Rect editBox;
 
     if (cmd->tx_argc != 2)
     {
@@ -4085,7 +4089,7 @@ CmdDrop(w, cmd)
 	return;
     }
 
-    if (!ToolGetEditBox((Rect *)NULL)) return;
+    if (!ToolGetEditBox(&editBox)) return;
     if (!CmdParseLayers(cmd->tx_argv[1], &lMask))
 	return;
 
@@ -4121,6 +4125,10 @@ CmdDrop(w, cmd)
 			    cmdDropFunc, (ClientData)&lMask);
 	}
     }
+
+    DRCCheckThis(EditCellUse->cu_def, TT_CHECKPAINT, &editBox);
+    DBWAreaChanged(EditCellUse->cu_def, &editBox, DBW_ALLWINDOWS, &tMask);
+    DBReComputeBbox(EditCellUse->cu_def);
 }
 
 /*
diff --git a/commands/CmdRS.c b/commands/CmdRS.c
index 992987c0..86fc0760 100644
--- a/commands/CmdRS.c
+++ b/commands/CmdRS.c
@@ -663,6 +663,8 @@ cmdIntersectArea(layer)
     int windowMask, xMask;
     DBWclientRec *crec;
     MagWindow *window;
+    char *lptr;
+    bool negate = FALSE;
 
     bzero(&scx, sizeof(SearchContext));
     window = ToolGetBoxWindow(&scx.scx_area, &windowMask);
@@ -694,8 +696,23 @@ cmdIntersectArea(layer)
     scx.scx_use = (CellUse *) window->w_surfaceID;
     scx.scx_trans = GeoIdentityTransform;
     crec = (DBWclientRec *) window->w_clientData;
-    ttype = DBTechNoisyNameType(layer);
-    SelectIntersect(&scx, ttype, crec->dbw_bitmask);
+
+    /* Special behavior:  "!" or "~" in front of layer name intersects	*/
+    /* with NOT(layer).							*/
+
+    lptr = layer;
+    if ((*lptr == '~') || (*lptr == '!'))
+    {
+	negate = TRUE;
+	lptr++;
+    }
+    
+    ttype = DBTechNameType(lptr);
+    if (ttype < 0) {
+	TxError("Cannot parse layer type \"%s\".\n", layer);
+	return;
+    }
+    SelectIntersect(&scx, ttype, crec->dbw_bitmask, negate);
 }
 
 /*
diff --git a/select/selCreate.c b/select/selCreate.c
index ebb92793..4a7124a2 100644
--- a/select/selCreate.c
+++ b/select/selCreate.c
@@ -324,7 +324,7 @@ selIntersectPaintFunc(tile)
  */
 
 void
-SelectIntersect(scx, type, xMask)
+SelectIntersect(scx, type, xMask, negate)
     SearchContext *scx;		/* Describes the area in which material
 				 * is to be selected.  The resulting
 				 * coordinates should map to the coordinates
@@ -339,6 +339,7 @@ SelectIntersect(scx, type, xMask)
 				 * considered.  0 means treat everything as
 				 * expanded.
 				 */
+    bool negate;		/* If true, search on NOT(type) */
 {
     TileTypeBitMask tMask, rMask;
     TileType s, t;
@@ -363,15 +364,23 @@ SelectIntersect(scx, type, xMask)
 
     /* Select all paint of type "type" and copy into SelectDef */
     TTMaskSetOnlyType(&tMask, type);
-    plane = DBPlane(t);
+
+    plane = DBPlane(type);
     (void) DBCellCopyAllPaint(scx, &tMask, xMask, SelectUse);
 
     /* Scan Select2Def for all geometry inside the area of "type", and  */
     /* copy back to SelectDef as "type"					*/
 
+    if (negate)
+    {
+	TTMaskCom(&tMask);
+	TTMaskAndMask(&tMask, &DBPlaneTypes[plane]);
+    }
     DBSrPaintArea((Tile *)NULL, SelectDef->cd_planes[plane],
 	    &scx->scx_area, &tMask, selIntersectPaintFunc, (ClientData)NULL);
 
+    if (negate) TTMaskSetOnlyType(&tMask, type);    /* Restore original mask */
+
     DBEraseMask(SelectDef, &TiPlaneRect, &tMask);
 
     /* Display the new selection. */