[PATCH] avoid more undefined handler

[PATCH] avoid more undefined handler

[Jim Meyering]

Clang also warned about this:

    ANALYZE: eval.c evalpipe
    eval.c:575:10: warning: Assigned value is garbage or undefined
                    prevfd = pip[0];
                           ^ ~~~~~~

Here's a fix:

2011-05-25  Jim Meyering  <meyering@redhat.com>

	avoid more undefined handler
	* src/eval.c (evalpipe): Ensure that pip[0] is defined before used.


From dca635b44d289eeb6b7d0fb6a60db37fb61bc863 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Wed, 25 May 2011 14:35:24 +0200
Subject: [PATCH] avoid more undefined handler

* src/eval.c (evalpipe): Ensure that pip[0] is defined before used.

Signed-off-by: Jim Meyering <meyering@redhat.com>
---
 src/eval.c |    1 +
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/eval.c b/src/eval.c
index 911fb2c..a93e602 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -547,6 +547,7 @@ evalpipe(union node *n, int flags)
 	prevfd = -1;
 	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
 		prehash(lp->n);
+		pip[0] = -1;
 		pip[1] = -1;
 		if (lp->next) {
 			if (pipe(pip) < 0) {
--
1.7.5.2.609.g6dbbf

Re: [PATCH] avoid more undefined handler

[Herbert Xu]

On Wed, May 25, 2011 at 12:38:09PM +0000, Jim Meyering wrote:
> Clang also warned about this:
> 
>     ANALYZE: eval.c evalpipe
>     eval.c:575:10: warning: Assigned value is garbage or undefined
>                     prevfd = pip[0];
>                            ^ ~~~~~~

This isn't really a bug.  If pip[0] is garbage at this point, then
we're the last element in a pipeline and prevfd will never be used
again.

If you can think of a way of solving this without adding to the code
size then I'll gladly apply it :)

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt