Fix config_file file leak.

Hi,

We are using Sentry (a C/C++ static analysis tool) to analyze git on a nightly basis. Sentry found that a file leak was recently introduced in the commit 924aaf3.

I'm hoping the attached patch correctly fixes up this leak.

Thanks,
Chris

Chris Wilson
http://vigilantsw.com/
Vigilant Software, A C/C++ Static Analysis Company

---
 config.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

index 1fc063b..bf61f09 100644
@@ -1434,7 +1434,7 @@ int git_config_rename_section(const char *old_name, const char *new
        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
        int out_fd;
        char buf[1024];
-       FILE *config_file;
+       FILE *config_file = 0;
 
        if (config_exclusive_filename)
                config_filename = xstrdup(config_exclusive_filename);

@@ -1498,12 +1498,13 @@ int git_config_rename_section(const char *old_name, const char *n
                        goto out;
                }
        }
-       fclose(config_file);
  unlock_and_out:
        if (commit_lock_file(lock) < 0)
                ret = error("could not commit config file %s", config_filename);
  out: 
        free(config_filename);
+        if (config_file)
+               fclose(config_file);
        return ret;
 }
 

1.7.0.4

Oops, sorry if I was unclear. This happens in config.c here,
http://git.kernel.org/?p=git/git.git;a=blob;f=config.c;h=1fc063b2562101687b9215e5b697a91fcffdd5bb;hb=924aaf3ef764a5e8e976f68e024ecacf54ff6306

This happens once the file is opened successfully here,
1449 if (!(config_file = fopen(config_filename, "rb"))) {
and then you enter the while loop here,
1454 while (fgets(buf, sizeof(buf), config_file)) {
and then you take any 'goto out;' in the while loop, which doesn't close the file handle.

1505 out:
1506 free(config_filename);
1507 return ret;
1508 }

Chris

Hmmm ..., commit 924aaf3 did *not* introduce a file handle leak. It would seem that the change in scope of the file handle made it easier for Sentry to see the *existing* (potential) file handle leak.

no?

Other than that, ...

ATB,
Ramsay Jones

Ah yes, that does seem like that case. Thanks for pointing that out.

Looks like this file handle will leak whenever a write fails.

Chris