Re: [PATCH] force_object_loose: Fix memory leak

> read_packed_sha1 expectes its caller to free the buffer it returns, which
> force_object_loose didn't do.
> 
> This leak is eventually triggered by "git gc", when it is manually invoked
> or there are too many packs around, making gc totally unusable when there
> are lots of unreachable objects.
> 
> Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>

> ---
> Tested with a somewhat recent clone of linux-2.6.git:
> 
> git clone linux-2.6 test
> cd test
> git remote rm origin
> git reset --hard v2.6.16
> git for-each-ref --format='%(refname)' refs/tags | \
> 	xargs -i git update-ref -d {}
> git reflog expire --expire=0 --all
> git repack -Ad
> 
> Without the fix, I killed repack when its memory usage got past 3 _GB_.
> With the fix, it stays at around 300MB until it starts writing the
> new pack, then it goes up to about 550MB or so.
> 
>  sha1_file.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/sha1_file.c b/sha1_file.c
> index 3fbb082..70bb453 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -2333,6 +2333,7 @@ int force_object_loose(const unsigned char *sha1, time_t mtime)
>  	enum object_type type;
>  	char hdr[32];
>  	int hdrlen;
> +	int ret;
>  
>  	if (has_loose_object(sha1))
>  		return 0;
> @@ -2340,7 +2341,10 @@ int force_object_loose(const unsigned char *sha1, time_t mtime)
>  	if (!buf)
>  		return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
>  	hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
> -	return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
> +	ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
> +	free(buf);
> +
> +	return ret;
>  }
>  
>  int has_pack_index(const unsigned char *sha1)
> -- 
> 1.6.0.2.541.g46dc1.dirty
> --
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