Re: git bug(?) for commit baf18fc261ca475343fe3cb9cd2c0dded4bc1bb7

[Tony Wang <wwwjfy@gmail.com>]

On Monday, November 7, 2011 at 18:41, Nguyen Thai Ngoc Duy wrote:
> On Mon, Nov 07, 2011 at 05:48:25PM +0800, Tony Wang wrote:
> > > It was on purpose. HEAD may contain a tag, in which case
> > > lookup_commit() would to return a commit fail while
> > > lookup_commit_reference() can peel the tag to the commit.
> > 
> > 
> > 
> > However, I tried to make it lookup_commit and it worked as expected. I'll try to read some detail. 
> 
> and the strange value of branch "s/origin/b" in your previous message..
that's the strange thing. seems like part of the string "refs/origin/b" 
> 
> > > 
> > > > I tried to debug, and found after this
> > > > merge.c:1104
> > > > head_commit = lookup_commit_or_die(head_sha1, "HEAD");
> > > > the variable branch becomes "s/origin/b", which is previously "b".
> > > 
> > 
> 
> 
> 
> ..led me to think that it's because branch points to the static buffer
> returned by by resolve_ref().
> 
> lookup_commit_reference() may call resolve_ref() again and change the
> buffer value, which also changes "branch" variable.
> 
> So, does this help?
> 
> -- 8< --
> diff --git a/builtin/merge.c b/builtin/merge.c
> index 581f494..4f20833 100644
> --- a/builtin/merge.c
> +++ b/builtin/merge.c
> @@ -1029,7 +1029,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
> * Check if we are _not_ on a detached HEAD, i.e. if there is a
> * current branch.
> */
> - branch = resolve_ref("HEAD", head_sha1, 0, &flag);
> + branch = xstrdup(resolve_ref("HEAD", head_sha1, 0, &flag));
> if (branch && !prefixcmp(branch, "refs/heads/"))
> branch += 11;
> if (!branch || is_null_sha1(head_sha1))
> -- 8< --

Yes! It works.
I do learn from it, thanks!
But seems it's possible the potential problem exists somewhere else.
> -- 
> Duy



-- 
BR,
Tony Wang