This commit adds an additional function to the substrate generation,

effectively forcing the substrate type (e.g., "pwell") to be defined
as delineating isolated substrate areas only (e.g., pwell in deep nwell
or isosub a.k.a. subcut).  It does so by erasing all of the substrate
type out of a cell prior to extraction before redrawing it in the
isolated areas.  This avoids issues caused by pwell drawn in separate
unconnected areas of a cell, as these are removed and the area treated
as the default substrate everywhere.  Has worked on all layouts tested
so far.

extract/ExtBasic.c

@@ -3693,10 +3693,7 @@ extFindNodes(def, clipArea, subonly)
     temp_subsnode = (NodeRegion *)NULL;		// Reset for new search
     isabstract = FALSE;
 
-    // NOTE:  Commented out 12/17/2022.  This does not produce the intended
-    // result when an abstract view contains well and substrate types.
-    // Not sure if commenting it out produces the intended result when an
-    // abstract view does NOT contain will and substrate types, though.
+    // Do not treat abstract cells differently per the substrate.
     /* DBPropGet(def, "LEFview", &isabstract); */
 
     if (!isabstract)