allow NULL for indexPtr to say "am not interested in index, just membership in set of possibilities" for Tcl_GetIndexFromObj()

1 files changed, 18 insertions, 13 deletions

diff --git a/generic/tclIndexObj.c b/generic/tclIndexObj.c
index 89582b7..c3092c9 100644
--- a/generic/tclIndexObj.c
+++ b/generic/tclIndexObj.c
@@ -166,11 +166,12 @@ GetIndexFromObjList(
  * Results:
  *	If the value of objPtr is identical to or a unique abbreviation for
  *	one of the entries in tablePtr, then the return value is TCL_OK and
- *	the index of the matching entry is stored at *indexPtr. If there isn't
- *	a proper match, then TCL_ERROR is returned and an error message is
- *	left in interp's result (unless interp is NULL). The msg argument is
- *	used in the error message; for example, if msg has the value "option"
- *	then the error message will say something like 'bad option "foo": must
+ *	the index of the matching entry is stored at *indexPtr
+ *	(unless indexPtr is NULL). If there isn't a proper match, then
+ *	TCL_ERROR is returned and an error message is left in interp's
+ *	result (unless interp is NULL). The msg argument is used in the
+ *	error message; for example, if msg has the value "option" then
+ *	the error message will say something like 'bad option "foo": must
  *	be ...'
  *
  * Side effects:
@@ -212,15 +213,17 @@ Tcl_GetIndexFromObjStruct(
      */
 
     if (!(flags & TCL_INDEX_TEMP_TABLE)) {
-    irPtr = TclFetchIntRep(objPtr, &indexType);
-    if (irPtr) {
-	indexRep = (IndexRep *)irPtr->twoPtrValue.ptr1;
-	if (indexRep->tablePtr==tablePtr && indexRep->offset==offset) {
-	    *indexPtr = indexRep->index;
-	    return TCL_OK;
+	irPtr = TclFetchIntRep (objPtr, &indexType);
+	if (irPtr) {
+	    indexRep = (IndexRep *) irPtr->twoPtrValue.ptr1;
+	    if (indexRep->tablePtr == tablePtr && indexRep->offset == offset) {
+		if (indexPtr != NULL) {
+		    *indexPtr = indexRep->index;
+		}
+		return TCL_OK;
+	    }
 	}
     }
-    }
 
     /*
      * Lookup the value of the object in the table. Accept unique
@@ -291,7 +294,9 @@ Tcl_GetIndexFromObjStruct(
     indexRep->index = index;
     }
 
-    *indexPtr = index;
+    if(indexPtr != NULL) {
+      *indexPtr = index;
+    }
     return TCL_OK;
 
   error: