Re: fc -lr broken in current git?

[Peter Stephenson <Peter.Stephenson@csr.com>]

On Mon, 30 Apr 2012 13:46:14 +0100
Peter Stephenson <Peter.Stephenson@csr.com> wrote:
> On Mon, 30 Apr 2012 14:07:09 +0200
> Hauke Petersen <hkptrsn@googlemail.com> wrote:
> > fc -lr seems to be problematic in current git:
> 
> Yes, it doesn't take account of the -r flag.
> 
> I wonder if a better fix is only to check the order when actually
> executing code, which is where the problems happened.

This will allow listing in any order, but not allow any execution out of
order, even if the -r flag is explicitly given.  That should be enough
to prevent bad behaviour; does it disallow anything useful?  I think
deliberately reversing the order of commands using the history mechanism
is a *very* abstruse use.

Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.256
diff -p -u -r1.256 builtin.c
--- Src/builtin.c	7 Mar 2012 06:10:42 -0000	1.256
+++ Src/builtin.c	3 May 2012 09:12:41 -0000
@@ -1498,7 +1498,7 @@ bin_fc(char *nam, char **argv, Options o
     }
     if (OPT_ISSET(ops,'l')) {
 	/* list the required part of the history */
-	retval = fclist(stdout, ops, first, last, asgf, pprog);
+	retval = fclist(stdout, ops, first, last, asgf, pprog, 0);
 	unqueue_signals();
     }
     else {
@@ -1530,7 +1530,7 @@ bin_fc(char *nam, char **argv, Options o
 		}
 	    }
 	    ops->ind['n'] = 1;	/* No line numbers here. */
-	    if (!fclist(out, ops, first, last, asgf, pprog)) {
+	    if (!fclist(out, ops, first, last, asgf, pprog, 1)) {
 		char *editor;
 
 		if (func == BIN_R)
@@ -1639,7 +1639,7 @@ fcsubs(char **sp, struct asgment *sub)
 /**/
 static int
 fclist(FILE *f, Options ops, zlong first, zlong last,
-       struct asgment *subs, Patprog pprog)
+       struct asgment *subs, Patprog pprog, int is_command)
 {
     int fclistdone = 0;
     zlong tmp;
@@ -1652,8 +1652,8 @@ fclist(FILE *f, Options ops, zlong first
 	last = first;
 	first = tmp;
     }
-    if (first > last) {
-	zwarnnam("fc", "history events are in wrong order, aborted");
+    if (is_command && first > last) {
+	zwarnnam("fc", "history events can't be executed backwards, aborted");
 	if (f != stdout)
 	    fclose(f);
 	return 1;

-- 
Peter Stephenson <pws@csr.com>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


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