diff --git a/VERSION b/VERSION
index 807bada7..aa16d4ea 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.258
+8.3.259
diff --git a/calma/CalmaRdcl.c b/calma/CalmaRdcl.c
index 7a45a437..cf81d1b1 100644
--- a/calma/CalmaRdcl.c
+++ b/calma/CalmaRdcl.c
@@ -50,6 +50,7 @@ int calmaNonManhattan;
 int CalmaFlattenLimit = 10;
 int NameConvertErrors = 0;
 bool CalmaRewound = FALSE;
+bool CalmaMaskHints = FALSE;
 
 extern HashTable calmaDefInitHash;
 
diff --git a/calma/calma.h b/calma/calma.h
index de0314f1..0d4aa223 100644
--- a/calma/calma.h
+++ b/calma/calma.h
@@ -34,6 +34,7 @@ extern bool CalmaAddendum;
 extern bool CalmaNoDuplicates;
 extern bool CalmaNoDateStamp;
 extern bool CalmaUnique;
+extern bool CalmaMaskHints;
 extern bool CalmaMergeTiles;
 extern bool CalmaFlattenArrays;
 extern bool CalmaNoDRCCheck;
diff --git a/cif/CIFhier.c b/cif/CIFhier.c
index ed8538f8..e51d5894 100644
--- a/cif/CIFhier.c
+++ b/cif/CIFhier.c
@@ -310,6 +310,7 @@ cifFlatMaskHints(name, value, mhd)
 		if (lastval) freeMagic(lastval);
 
 		/* Parse through the four values and check if there's more */
+		while (*vptr && isspace(*vptr)) vptr++;
 		while (*vptr && !isspace(*vptr)) vptr++;
 		while (*vptr && isspace(*vptr)) vptr++;
 		while (*vptr && !isspace(*vptr)) vptr++;
diff --git a/cif/CIFrdcl.c b/cif/CIFrdcl.c
index 5a69f0ab..2986e1b7 100644
--- a/cif/CIFrdcl.c
+++ b/cif/CIFrdcl.c
@@ -540,6 +540,40 @@ cifCopyPaintFunc(tile, cifCopyRec)
     return 0;
 }
 
+/*
+ * ----------------------------------------------------------------------------
+ *
+ * cifMaskHintFunc --
+ *
+ * For each tile in the scanned plane, convert the tile into a coordinate
+ * string by appending the coordinates to the list passed as clientData.
+ *
+ * Results:
+ *	Return 0 to keep the search going.
+ *
+ * Side effects:
+ *	Allocates memory for and seeds a linked rect entry
+ *
+ * ----------------------------------------------------------------------------
+ */
+
+int
+cifMaskHintFunc(tile, lrecp)
+    Tile *tile;
+    LinkedRect **lrecp;
+{
+    Rect r;
+    LinkedRect *newlr;
+
+    newlr = (LinkedRect *)mallocMagic(sizeof(LinkedRect));
+    newlr->r_next = *lrecp;
+    (*lrecp) = newlr;
+
+    TiToRect(tile, &newlr->r_r);
+
+    return 0;
+}
+
 /*
  * ----------------------------------------------------------------------------
  *
@@ -683,6 +717,159 @@ CIFPaintCurrent(filetype)
 	TiFreePlane(plane);
     }
 
+    /* If mask hints were requested, then for each GDS/CIF layer in the	*/
+    /* input, if the layer has a corresponding output layer and the	*/
+    /* output layer has a mask hints operator, then generate the output	*/
+    /* plane for that layer, compare to the input plane, and create	*/
+    /* mask hint properties to make the output the same as the input.	*/
+
+    if (CalmaMaskHints)
+    {
+	int j;
+    	CIFOp *op, newop, subop;
+	Plane *presult;
+	TileTypeBitMask genMask;
+	int *in_out_map;
+	extern char *(cifReadLayers[MAXCIFRLAYERS]);
+
+	TTMaskZero(&genMask);
+	in_out_map = (int *)mallocMagic(cifNReadLayers * sizeof(int));
+
+    	for (i = 0; i < cifNReadLayers; i++)
+	{
+	    /* Does the input layer have a corresponding output layer? */
+	    in_out_map[i] = -1;
+	    for (j = 0; j < CIFCurStyle->cs_nLayers; j++)
+	    {
+		if (!strcmp(CIFCurStyle->cs_layers[j]->cl_name, cifReadLayers[i]))
+		{
+	    	    /* Does the layer have a mask-hints operator? */
+	    	    for (op = CIFCurStyle->cs_layers[j]->cl_ops; op; op = op->co_next)
+		    	if (op->co_opcode == CIFOP_MASKHINTS)
+		    	{
+			    TTMaskSetType(&genMask, j);
+			    in_out_map[i] = j;
+			    break;
+		    	}
+		}
+		if (in_out_map[i] >= 0) break;
+	    }
+	}
+
+	/* Multiply input planes to the same scale as the generated output */
+	CIFScalePlanes(CIFCurStyle->cs_scaleFactor, 1, cifCurReadPlanes);
+
+	/* Generate the output for these layers from the cell contents */
+	CIFClearPlanes(CIFPlanes);
+
+	/* TO-DO:  Replace DBAllTypeBits with genMask.  Requires that genMask	*/
+	/* be expanded to include all dependent layers.				*/
+	CIFGen(cifReadCellDef, cifReadCellDef, &TiPlaneRect, CIFPlanes, &DBAllTypeBits,
+			TRUE, FALSE, FALSE, (ClientData)NULL);
+
+	/* Set up double operator for OR and ANDNOT functions */
+	newop.co_opcode = CIFOP_OR;
+	newop.co_distance = 0;
+	newop.co_next = &subop;
+	newop.co_client = (ClientData)NULL;
+	TTMaskZero(&newop.co_paintMask);
+
+	subop.co_opcode = CIFOP_ANDNOT;
+	subop.co_distance = 0;
+	subop.co_next = NULL;
+	subop.co_client = (ClientData)NULL;
+	TTMaskZero(&subop.co_paintMask);
+
+    	for (i = 0; i < cifNReadLayers; i++)
+	{
+	    LinkedRect *lrec = NULL;
+	    char *propstr = NULL;
+	    char locstr[512];
+	    Plane *tempp;
+
+	    j = in_out_map[i];
+	    if (j < 0) continue;
+
+	    TTMaskSetOnlyType(&subop.co_cifMask, j);
+
+	    /* Replace last layer + 1 on CIFPlanes with input layer i */
+
+	    tempp = CIFPlanes[CIFCurStyle->cs_nLayers];
+	    TTMaskSetOnlyType(&newop.co_cifMask, CIFCurStyle->cs_nLayers);
+	    CIFPlanes[CIFCurStyle->cs_nLayers] = cifCurReadPlanes[i];
+	    CIFCurStyle->cs_nLayers++;
+
+	    /* Compute result (i AND-NOT j), which will be all the areas of
+	     * the input on layer i that are not generated by writing output
+	     * layer j.
+	     */
+	    presult = CIFGenLayer(&newop, &TiPlaneRect, (CellDef *)NULL,
+			(CellDef *)NULL, CIFPlanes, FALSE, (ClientData)NULL);
+
+	    /* Scan the resulting plane and generate linked Rect structures for
+	     * each shape found.
+	     */
+	    DBSrPaintArea((Tile *)NULL, presult, &TiPlaneRect, &CIFSolidBits,
+			cifMaskHintFunc, (ClientData)&lrec);
+
+	    if (lrec != NULL)
+	    {
+		char *propname;
+
+	    	propname = (char *)mallocMagic(11 + strlen(cifReadLayers[i]));
+	    	sprintf(propname, "MASKHINTS_%s", cifReadLayers[i]);
+
+	    	propstr = (char *)NULL;
+
+	    	/* Turn all linked Rects into a mask-hints property in the
+		 * target cell.
+		 */
+	    	while (lrec != NULL)
+	    	{
+		    char *newstr;
+		    sprintf(locstr, "%d %d %d %d",
+				lrec->r_r.r_xbot / CIFCurStyle->cs_scaleFactor,
+				lrec->r_r.r_ybot / CIFCurStyle->cs_scaleFactor,
+				lrec->r_r.r_xtop / CIFCurStyle->cs_scaleFactor,
+				lrec->r_r.r_ytop / CIFCurStyle->cs_scaleFactor);
+		    if (propstr == NULL)
+		    {
+		    	newstr = (char *)mallocMagic(strlen(locstr) + 1);
+		    	sprintf(newstr, "%s", locstr);
+		    }
+		    else
+		    {
+		    	newstr = (char *)mallocMagic(strlen(locstr)
+					+ strlen(propstr) + 2);
+		    	sprintf(newstr, "%s %s", propstr, locstr);
+		    	freeMagic(propstr);
+		    }
+		    propstr = newstr;
+		    freeMagic(lrec);
+		    lrec = lrec->r_next;
+	    	}
+		/* NOTE: propstr is transferred to the CellDef and should
+		 * not be free'd here.
+		 */
+		DBPropPut(cifReadCellDef, propname, propstr);
+	    	freeMagic(propname);
+	    }
+
+	    /* Delete the generated plane */
+	    DBFreePaintPlane(presult);
+	    TiFreePlane(presult);
+
+	    /* Replace the input plane that was shuffled out */
+	    CIFCurStyle->cs_nLayers--;
+	    CIFPlanes[CIFCurStyle->cs_nLayers] = tempp;
+	}
+
+	/* Free up the planes used to create the output */
+	CIFClearPlanes(CIFPlanes);
+
+	freeMagic((char *)in_out_map);
+    }
+
     /* Now go through all the current planes and zero them out. */
 
     for (i = 0; i < MAXCIFRLAYERS; i++)
diff --git a/commands/CmdCD.c b/commands/CmdCD.c
index f9936f49..f937f2a2 100644
--- a/commands/CmdCD.c
+++ b/commands/CmdCD.c
@@ -99,18 +99,19 @@ bool cmdDumpParseArgs();
 #define	CALMA_LABELS	8
 #define	CALMA_LIBRARY	9
 #define	CALMA_LOWER	10
-#define CALMA_MERGE	11
-#define CALMA_NO_STAMP	12
-#define CALMA_NO_DUP	13
-#define CALMA_READ	14
-#define CALMA_READONLY	15
-#define CALMA_RESCALE	16
-#define CALMA_WARNING	17
-#define CALMA_WRITE	18
-#define CALMA_POLYS	19
-#define CALMA_PATHS	20
-#define CALMA_UNDEFINED	21
-#define CALMA_UNIQUE	22
+#define CALMA_MASKHINTS	11
+#define CALMA_MERGE	12
+#define CALMA_NO_STAMP	13
+#define CALMA_NO_DUP	14
+#define CALMA_READ	15
+#define CALMA_READONLY	16
+#define CALMA_RESCALE	17
+#define CALMA_WARNING	18
+#define CALMA_WRITE	19
+#define CALMA_POLYS	20
+#define CALMA_PATHS	21
+#define CALMA_UNDEFINED	22
+#define CALMA_UNIQUE	23
 
 #define CALMA_WARN_HELP CIF_WARN_END	/* undefined by CIF module */
 
@@ -145,6 +146,7 @@ CmdCalma(w, cmd)
 	"labels [yes|no]	cause labels to be output when writing GDS-II",
 	"library [yes|no]	do not output the top level, only subcells",
 	"lower [yes|no]		allow both upper and lower case in labels",
+	"maskhints [yes|no]	generate mask hint properties on input",
 	"merge [yes|no]		merge tiles into polygons in the output",
 	"nodatestamp [yes|no]	write a zero value creation date stamp",
 	"noduplicates [yes|no]	do not read cells that exist before reading GDS",
@@ -537,6 +539,28 @@ CmdCalma(w, cmd)
 	    CalmaDoLower = (option < 4) ? FALSE : TRUE;
 	    return;
 
+	case CALMA_MASKHINTS:
+	    if (cmd->tx_argc == 2)
+	    {
+#ifdef MAGIC_WRAPPER
+		Tcl_SetObjResult(magicinterp, Tcl_NewBooleanObj(CalmaMaskHints));
+#else
+		if (CalmaMaskHints)
+		    TxPrintf("Mask hints generated from GDS input.\n");
+		else
+		    TxPrintf("No mask hints generated from GDS input.\n");
+#endif
+		return;
+	    }
+	    else if (cmd->tx_argc != 3)
+		goto wrongNumArgs;
+
+	    option = Lookup(cmd->tx_argv[2], cmdCalmaYesNo);
+	    if (option < 0)
+		goto wrongNumArgs;
+	    CalmaMaskHints = (option < 4) ? FALSE : TRUE;
+	    return;
+
 	case CALMA_MERGE:
 	    if (cmd->tx_argc == 2)
 	    {