Re: Seg. Fault when calling "cd" with set "chpwd" hook from a widget

[Peter Stephenson <pws@xxxxxxx>]

On Tue, 25 Nov 2008 01:05:37 +0100
Jonas Kramer <jkramer@xxxxxxxxxxxxxxxx> wrote:
> Hi workers,
> 
> I've experienced a seg. fault in zsh when doing the following:
>...
> This seems to happen in
> hist.c:1138, where hptr points to NULL at that point. I tried to fix it
> myself, but I can't find a clean solution as I can't find the source of
> the problem. Just checking for hptr being NULL in hend() would just fix
> the symptom, not the cause I guess.

Actually, I think that's the right fix:  I recently moved the *hptr = '\0'
up to that point because in some cases chline gets accessed quite early,
but I didn't do the checks that are usually done before accessing it.

Index: Src/hist.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/hist.c,v
retrieving revision 1.85
diff -u -r1.85 hist.c
--- Src/hist.c	22 Sep 2008 08:47:01 -0000	1.85
+++ Src/hist.c	25 Nov 2008 18:34:28 -0000
@@ -1130,12 +1130,14 @@
      && (hist_ignore_all_dups = isset(HISTIGNOREALLDUPS)) != 0)
 	histremovedups();
 
-    /*
-     * Added the following in case the test "hptr < chline + 1"
-     * is more than just paranoia.
-     */
-    DPUTS(hptr < chline, "History end pointer off start of line");
-    *hptr = '\0';
+    if (hptr) {
+	/*
+	 * Added the following in case the test "hptr < chline + 1"
+	 * is more than just paranoia.
+	 */
+	DPUTS(hptr < chline, "History end pointer off start of line");
+	*hptr = '\0';
+    }
     addlinknode(hookargs, "zshaddhistory");
     addlinknode(hookargs, chline);
     callhookfunc("zshaddhistory", hookargs, 1, &hookret);


-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070