Fix [Bug 2673163]

1 files changed, 38 insertions, 8 deletions

diff --git a/generic/tclVar.c b/generic/tclVar.c
index e61e06e..d87cdf9 100644
--- a/generic/tclVar.c
+++ b/generic/tclVar.c
@@ -16,7 +16,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclVar.c,v 1.177 2009/03/18 16:52:20 dgp Exp $
+ * RCS: @(#) $Id: tclVar.c,v 1.178 2009/03/24 09:30:07 dkf Exp $
  */
 
 #include "tclInt.h"
@@ -4077,29 +4077,59 @@ Tcl_UpvarObjCmd(
     Tcl_Obj *const objv[])	/* Argument objects. */
 {
     CallFrame *framePtr;
-    int result;
+    int result, hasLevel;
+    Tcl_Obj *levelObj;
 
     if (objc < 3) {
-    upvarSyntax:
 	Tcl_WrongNumArgs(interp, 1, objv,
 		"?level? otherVar localVar ?otherVar localVar ...?");
 	return TCL_ERROR;
     }
 
+    if (objc & 1) {
+	/*
+	 * Even number of arguments, so use the default level of "1" by
+	 * passing NULL to TclObjGetFrame.
+	 */
+
+	levelObj = NULL;
+	hasLevel = 0;
+    } else {
+	/*
+	 * Odd number of arguments, so objv[1] must contain the level.
+	 */
+
+	levelObj = objv[1];
+	hasLevel = 1;
+    }
+
     /*
      * Find the call frame containing each of the "other variables" to be
      * linked to.
      */
 
-    result = TclObjGetFrame(interp, objv[1], &framePtr);
+    result = TclObjGetFrame(interp, levelObj, &framePtr);
     if (result == -1) {
 	return TCL_ERROR;
     }
-    objc -= result+1;
-    if ((objc & 1) != 0) {
-	goto upvarSyntax;
+    if ((result == 0) && hasLevel) {
+	/*
+	 * Synthesize an error message since TclObjGetFrame doesn't do this
+	 * for this particular case.
+	 */
+
+	Tcl_AppendResult(interp, "bad level \"", TclGetString(levelObj), "\"",
+		NULL);
+	Tcl_SetErrorCode(interp, "TCL", "VALUE", "LEVEL", NULL);
+	return TCL_ERROR;
     }
-    objv += result+1;
+
+    /*
+     * We've now finished with parsing levels; skip to the variable names.
+     */
+
+    objc -= hasLevel+1;
+    objv += hasLevel+1;
 
     /*
      * Iterate over each (other variable, local variable) pair. Divide the