From: Sven Wischnowsky <wischnow@informatik.hu-berlin.de>
To: zsh-workers@sunsite.dk
Subject: Re: [falk@debian.org: Bug#107528: "while do done" gets into uninterruptable loop]
Date: Tue, 7 Aug 2001 15:55:53 +0200 (MET DST) [thread overview]
Message-ID: <200108071355.PAA04130@beta.informatik.hu-berlin.de> (raw)
In-Reply-To: <20010803105421.A14927@dman.com>
Clint Adams wrote:
> ...
>
> When I type "while do done", zsh loops without reacting to signals
> like Ctrl-c, Ctrl-\, kill -TERM. No problem with "while :; do
> done". The man page says
>
> while list do list done
>
> and list might be empty, so this should be valid syntax.
>
> I just noticed it returns immediately if $? happens to be non-zero. I
> think it should always loop infinitely. In any case, it should be
> interruptable.
Hmhm. This is because in such a loop none of the flags that are tested
in zhandler() ever gets set (line 519).
The patch below looks stupid (and it may well be), but it's the easiest
I can think of. I think I better not commit this until I get replies.
(Most of it is re-indentation of that loop, there's just a tiny bit of
added code at the top.)
Another thing we could try is to just add `|| loops' to that line in
signals.c but I'm not sure about what unwanted consequences that would
have.
Bye
Sven
Index: Src/loop.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/loop.c,v
retrieving revision 1.5
diff -u -r1.5 loop.c
--- Src/loop.c 2001/06/25 16:07:52 1.5
+++ Src/loop.c 2001/08/07 13:48:28
@@ -380,37 +380,53 @@
cmdpush(isuntil ? CS_UNTIL : CS_WHILE);
loops++;
loop = state->pc;
- for (;;) {
- state->pc = loop;
- noerrexit = 1;
- execlist(state, 1, 0);
- noerrexit = olderrexit;
- if (!((lastval == 0) ^ isuntil)) {
- if (breaks)
- breaks--;
- lastval = oldval;
- break;
- }
- if (retflag) {
- lastval = oldval;
- break;
- }
- execlist(state, 1, 0);
- if (breaks) {
- breaks--;
- if (breaks || !contflag)
- break;
- contflag = 0;
- }
- if (errflag) {
- lastval = 1;
- break;
- }
- if (retflag)
- break;
- freeheap();
- oldval = lastval;
- }
+
+ if (loop[0] == WC_END && loop[1] == WC_END) {
+
+ /* This is an empty loop. Make sure the signal handler sets the
+ * flags and then just wait for someone hitting ^C. */
+
+ int old_simple_pline = simple_pline;
+
+ simple_pline = 1;
+
+ while (!breaks)
+ ;
+ breaks--;
+
+ simple_pline = old_simple_pline;
+ } else
+ for (;;) {
+ state->pc = loop;
+ noerrexit = 1;
+ execlist(state, 1, 0);
+ noerrexit = olderrexit;
+ if (!((lastval == 0) ^ isuntil)) {
+ if (breaks)
+ breaks--;
+ lastval = oldval;
+ break;
+ }
+ if (retflag) {
+ lastval = oldval;
+ break;
+ }
+ execlist(state, 1, 0);
+ if (breaks) {
+ breaks--;
+ if (breaks || !contflag)
+ break;
+ contflag = 0;
+ }
+ if (errflag) {
+ lastval = 1;
+ break;
+ }
+ if (retflag)
+ break;
+ freeheap();
+ oldval = lastval;
+ }
cmdpop();
popheap();
loops--;
--
Sven Wischnowsky wischnow@informatik.hu-berlin.de
next prev parent reply other threads:[~2001-08-07 13:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-08-03 14:54 Clint Adams
2001-08-07 13:55 ` Sven Wischnowsky [this message]
2002-02-21 4:05 ` Clint Adams
2002-02-25 9:18 ` Sven Wischnowsky
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