bug 3588824 fix proposal

Index: generic/tkTextIndex.c
==================================================================
--- generic/tkTextIndex.c
+++ generic/tkTextIndex.c
@@ -758,18 +758,33 @@
 	sharedPtr = textPtr->sharedTextPtr;
     }
 
     /*
      *---------------------------------------------------------------------
-     * Stage 1: check to see if the index consists of nothing but a mark name.
+     * Stage 1: check to see if the index consists of nothing but a mark name,
+     * an embedded window name or an image name.
      * We do this check now even though it's also done later, in order to
-     * allow mark names that include funny characters such as spaces or "+1c".
+     * allow mark names, embedded window names or image names that include
+     * funny characters such as spaces or "+1c".
      *---------------------------------------------------------------------
      */
 
-    if (TkTextMarkNameToIndex(textPtr, string, indexPtr) == TCL_OK) {
-	goto done;
+    if (textPtr != NULL) {
+        /* 
+          * If textPtr is NULL, we have been called by the undo code
+          * with a numeric index of the form line.char
+          * so we skip these tests here
+          */
+        if (TkTextMarkNameToIndex(textPtr, string, indexPtr) == TCL_OK) {
+            goto done;
+        }
+	if (TkTextWindowIndex(textPtr, string, indexPtr) != 0) {
+	    goto done;
+	}
+	if (TkTextImageIndex(textPtr, string, indexPtr) != 0) {
+	    goto done;
+	}
     }
 
     /*
      *------------------------------------------------
      * Stage 2: start again by parsing the base index.

Index: generic/tkTextMark.c
==================================================================
--- generic/tkTextMark.c
+++ generic/tkTextMark.c
@@ -435,14 +435,10 @@
 {
     TkTextSegment *segPtr;
     TkTextIndex index;
     int start, end;
 
-    if (textPtr == NULL) {
-        return TCL_ERROR;
-    }
-
     if (!strcmp(name, "insert")) {
 	segPtr = textPtr->insertMarkPtr;
     } else if (!strcmp(name, "current")) {
 	segPtr = textPtr->currentMarkPtr;
     } else {