Re: [PATCH 01/15] read-cache: fix memleak

On Fri, Mar 20, 2015 at 8:26 PM, Junio C Hamano [off-list ref] wrote:

Stefan Beller [off-list ref] writes:

quoted

`ce` is allocated in make_cache_entry and should be freed if it is not
used any more. refresh_cache_entry as a wrapper around refresh_cache_ent
will either return `ce` or a new updated cache entry which is allocated
to new memory. In that case we need to free `ce` ourselfs.

Signed-off-by: Stefan Beller <redacted>
---
 read-cache.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/read-cache.c b/read-cache.c
index 8d71860..f72ea9f 100644
--- a/read-cache.c
+++ b/read-cache.c

@@ -747,6 +747,8 @@ struct cache_entry *make_cache_entry(unsigned int mode,
              free(ce);
              return NULL;
      } else {
+             if (ret != ce)
+                     free(ce);
              return ret;
      }
 }

Good, I vaguely recall that we did something similar in another
codepath that forgot the fact that refresh_cache_entry() may make
the incoming ce unnecessary.

As the rule is "if ret is different from ce, then ce must be freed"
in this codepath, I wonder if this is easier to read:

        ret = refresh_cache_entry(ce, ...);
        if (ret != ce)
                free(ce);
        return ret;

Indeed it is. Thanks for pointing out!

I'll send this as part of another series
applying on top of sb/leaks soon.