* generic/tclBasic.c (Tcl_DeleteCommandFromToken): One consequence

        of the NRE rewrite is that there are now situations where a NULL
        objProc field in a Command struct is perfectly normal.  Removed an
        outdated comment in Tcl_DeleteCommandFromToken that claimed we
        use (cmdPtr->objPtr == NULL) as a test of command validity.  In fact
        we use (cmdPtr->flags & CMD_IS_DELETED) to perform that test.
        Also removed the setting to NULL, since any extension following the
        advice of the old comment is going to be broken by NRE anyway, and
        needs to shift to flag-based testing (or stop intruding into
        such internal matters).  Part of [Bug 2486550].

2 files changed, 14 insertions, 11 deletions

diff --git a/ChangeLog b/ChangeLog
index 4a6cd70..c7fc057 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2009-01-12  Don Porter  <dgp@users.sourceforge.net>
+
+	* generic/tclBasic.c (Tcl_DeleteCommandFromToken): One consequence
+	of the NRE rewrite is that there are now situations where a NULL
+	objProc field in a Command struct is perfectly normal.  Removed an
+	outdated comment in Tcl_DeleteCommandFromToken that claimed we 
+	use (cmdPtr->objPtr == NULL) as a test of command validity.  In fact
+	we use (cmdPtr->flags & CMD_IS_DELETED) to perform that test.
+	Also removed the setting to NULL, since any extension following the
+	advice of the old comment is going to be broken by NRE anyway, and
+	needs to shift to flag-based testing (or stop intruding into
+	such internal matters).  Part of [Bug 2486550].
+
 2009-01-09  Don Porter  <dgp@users.sourceforge.net>
 
 	* generic/tclStringObj.c (STRING_SIZE): Corrected failure to limit
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index ab1806e..d39f73f 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.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: tclBasic.c,v 1.380 2009/01/09 11:21:45 dkf Exp $
+ * RCS: @(#) $Id: tclBasic.c,v 1.381 2009/01/12 16:50:03 dgp Exp $
  */
 
 #include "tclInt.h"
@@ -3000,16 +3000,6 @@ Tcl_DeleteCommandFromToken(
     }
 
     /*
-     * Mark the Command structure as no longer valid. This allows
-     * TclExecuteByteCode to recognize when a Command has logically been
-     * deleted and a pointer to this Command structure cached in a CmdName
-     * object is invalid. TclExecuteByteCode will look up the command again in
-     * the interpreter's command hashtable.
-     */
-
-    cmdPtr->objProc = NULL;
-
-    /*
      * Now free the Command structure, unless there is another reference to it
      * from a CmdName Tcl object in some ByteCode code sequence. In that case,
      * delay the cleanup until all references are either discarded (when a