Re: [bug-patch] [PATCH] avoid a used-uninitialized error

[Jim Meyering]

Andreas Gruenbacher wrote:

> On Tuesday 24 May 2011 13:15:37 Jim Meyering wrote:
>> I did not try to see if fixing this bug changes how patch works.
>
> It doesn't as far as I can see.  It doesn't fix a real bug either, but avoids
> a static checker error (so it's a good thing).  I'd rather initialize stamp
> completely at the top of the function though, like this:
>
> diff --git a/src/util.c b/src/util.c
> index 6950842..75486f4 100644
> --- a/src/util.c
> +++ b/src/util.c
> @@ -1428,6 +1428,7 @@ fetchname (char const *at, int strip_leading, bool 
> maybe_quoted, char **pname,
>      struct timespec stamp;
>
>      stamp.tv_sec = -1;
> +    stamp.tv_nsec = 0;
>
>      while (ISSPACE ((unsigned char) *at))
>       at++;
> @@ -1497,9 +1498,7 @@ fetchname (char const *at, int strip_leading, bool 
> maybe_quoted, char **pname,
>       timestr[u - t] = 0;
>        }
>
> -      if (*t == '\n')
> -     stamp.tv_sec = -1;
> -      else
> +      if (*t != '\n')

Ok.  I prefer that, too.
Thanks for the reviews.

>From b4c6b7086bd496bbc5b15de657247919a143e3b2 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <address@hidden>
Date: Tue, 24 May 2011 12:11:32 +0200
Subject: [PATCH] avoid a used-uninitialized error in fetchname

* src/util.c (fetchname): Avoid a used-uninitialized error.
Before, when "*t == '\n'", stamp.tv_nsec would have been
used undefined.  The fix is to set that member rather than
stamp.tv_sec, which is already set to the desired value.
This was reported by coverity.
---
 src/util.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/util.c b/src/util.c
index 6950842..75486f4 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1428,6 +1428,7 @@ fetchname (char const *at, int strip_leading, bool 
maybe_quoted, char **pname,
     struct timespec stamp;

     stamp.tv_sec = -1;
+    stamp.tv_nsec = 0;

     while (ISSPACE ((unsigned char) *at))
        at++;
@@ -1497,9 +1498,7 @@ fetchname (char const *at, int strip_leading, bool 
maybe_quoted, char **pname,
        timestr[u - t] = 0;
       }

-      if (*t == '\n')
-       stamp.tv_sec = -1;
-      else
+      if (*t != '\n')
        {
          if (! pstamp)
            {
--
1.7.5.2.609.g6dbbf