Index: generic/tclAPI.h
===================================================================
diff -u -r25b538dc2ef31223ad89edf12c3f6e60201049a8 -r533853e3ec6ac529b38d1d48e2fdb82ff7135429
--- generic/tclAPI.h	(.../tclAPI.h)	(revision 25b538dc2ef31223ad89edf12c3f6e60201049a8)
+++ generic/tclAPI.h	(.../tclAPI.h)	(revision 533853e3ec6ac529b38d1d48e2fdb82ff7135429)
@@ -640,7 +640,7 @@
     Tcl_Obj *pattern = (Tcl_Obj *)pc.clientData[2];
     int returnCode;
 
-    if (getMatchObject(interp, pattern,  objv[2], &patternObj, &patternString) == -1) {
+    if (getMatchObject(interp, pattern, objc>2 ? objv[2] : NULL, &patternObj, &patternString) == -1) {
       if (pattern) {
         DECR_REF_COUNT(pattern);
       }
@@ -718,7 +718,7 @@
     Tcl_Obj *pattern = (Tcl_Obj *)pc.clientData[3];
     int returnCode;
 
-    if (getMatchObject(interp, pattern,  objv[3], &patternObj, &patternString) == -1) {
+    if (getMatchObject(interp, pattern, objc>3 ? objv[3] : NULL, &patternObj, &patternString) == -1) {
       if (pattern) {
         DECR_REF_COUNT(pattern);
       }
@@ -753,7 +753,7 @@
     Tcl_Obj *pattern = (Tcl_Obj *)pc.clientData[3];
     int returnCode;
 
-    if (getMatchObject(interp, pattern,  objv[3], &patternObj, &patternString) == -1) {
+    if (getMatchObject(interp, pattern, objc>3 ? objv[3] : NULL, &patternObj, &patternString) == -1) {
       if (pattern) {
         DECR_REF_COUNT(pattern);
       }
@@ -842,7 +842,7 @@
     Tcl_Obj *pattern = (Tcl_Obj *)pc.clientData[2];
     int returnCode;
 
-    if (getMatchObject(interp, pattern,  objv[2], &patternObj, &patternString) == -1) {
+    if (getMatchObject(interp, pattern, objc>2 ? objv[2] : NULL, &patternObj, &patternString) == -1) {
       if (pattern) {
         DECR_REF_COUNT(pattern);
       }
@@ -1080,7 +1080,7 @@
     Tcl_Obj *pattern = (Tcl_Obj *)pc.clientData[3];
     int returnCode;
 
-    if (getMatchObject(interp, pattern,  objv[3], &patternObj, &patternString) == -1) {
+    if (getMatchObject(interp, pattern, objc>3 ? objv[3] : NULL, &patternObj, &patternString) == -1) {
       if (pattern) {
         DECR_REF_COUNT(pattern);
       }