patchmerge-ort: remove code obsoleted by other changes

> From: Elijah Newren <newren@gmail.com>
>
> Commit 66b209b86a ("merge-ort: implement CE_SKIP_WORKTREE handling with
> conflicted entries", 2021-03-20) added some code for merge-ort to handle
> conflicted and skip_worktree entries in general.  Included in this was
> an ugly hack for dealing with present-despite-skipped entries and a
> testcase (t6428.2) specific to that hack, since at that time users could
> accidentally get files into that state when using a sparse checkout.
>
> However, with the merging of 82386b4496 ("Merge branch
> 'en/present-despite-skipped'", 2022-03-09), that class of problems was
> addressed globally and in a much cleaner way.  As such, the
> present-despite-skipped hack in merge-ort is no longer needed and can
> simply be removed.
>
> No additional testcase is needed here; t6428.2 was written to test the
> necessary functionality and is being kept.  The fact that this test
> continues to pass despite the code being removed shows that the extra
> code is no longer necessary.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>     merge-ort: remove code obsoleted by other changes
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1302%2Fnewren%2Fnuke-present-despite-skipped-hack-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1302/newren/nuke-present-despite-skipped-hack-v1
> Pull-Request: https://github.com/git/git/pull/1302
>
>  merge-ort.c | 22 ++--------------------
>  1 file changed, 2 insertions(+), 20 deletions(-)

>
> diff --git a/merge-ort.c b/merge-ort.c
> index 8b7de0fbd8e..a6a3ab839a0 100644
> --- a/merge-ort.c
> +++ b/merge-ort.c
> @@ -491,7 +491,6 @@ enum conflict_and_info_types {
>  	CONFLICT_FILE_DIRECTORY,
>  	CONFLICT_DISTINCT_MODES,
>  	CONFLICT_MODIFY_DELETE,
> -	CONFLICT_PRESENT_DESPITE_SKIPPED,
>
>  	/* Regular rename */
>  	CONFLICT_RENAME_RENAME,   /* same file renamed differently */
> @@ -536,8 +535,6 @@ static const char *type_short_descriptions[] = {
>  	[CONFLICT_FILE_DIRECTORY] = "CONFLICT (file/directory)",
>  	[CONFLICT_DISTINCT_MODES] = "CONFLICT (distinct modes)",
>  	[CONFLICT_MODIFY_DELETE] = "CONFLICT (modify/delete)",
> -	[CONFLICT_PRESENT_DESPITE_SKIPPED] =
> -		"CONFLICT (upgrade your version of git)",
>
>  	/*** Regular rename ***/
>  	[CONFLICT_RENAME_RENAME] = "CONFLICT (rename/rename)",
> @@ -748,8 +745,7 @@ static void path_msg(struct merge_options *opt,
>  	/* Sanity checks */
>  	assert(omittable_hint ==
>  	       !starts_with(type_short_descriptions[type], "CONFLICT") ||
> -	       type == CONFLICT_DIR_RENAME_SUGGESTED ||
> -	       type == CONFLICT_PRESENT_DESPITE_SKIPPED);
> +	       type == CONFLICT_DIR_RENAME_SUGGESTED);
>  	if (opt->record_conflict_msgs_as_headers && omittable_hint)
>  		return; /* Do not record mere hints in headers */
>  	if (opt->priv->call_depth && opt->verbosity < 5)
> @@ -4377,22 +4373,8 @@ static int record_conflicted_index_entries(struct merge_options *opt)
>  			 * the CE_SKIP_WORKTREE bit and manually write those
>  			 * files to the working disk here.
>  			 */
> -			if (ce_skip_worktree(ce)) {
> -				struct stat st;
> -
> -				if (!lstat(path, &st)) {
> -					char *new_name = unique_path(opt,
> -								     path,
> -								     "cruft");
> -
> -					path_msg(opt, CONFLICT_PRESENT_DESPITE_SKIPPED, 1,
> -						 path, NULL, NULL, NULL,
> -						 _("Note: %s not up to date and in way of checking out conflicted version; old copy renamed to %s"),
> -						 path, new_name);
> -					errs |= rename(path, new_name);
> -				}
> +			if (ce_skip_worktree(ce))
>  				errs |= checkout_entry(ce, &state, NULL, NULL);
> -			}
>
>  			/*
>  			 * Mark this cache entry for removal and instead add
>
> base-commit: 6a475b71f8c4ce708d69fdc9317aefbde3769e25
> --
> gitgitgadget
>

>
> Hi Elijah,
>
> On Fri, 19 Aug 2022, Elijah Newren via GitGitGadget wrote:
>
> > From: Elijah Newren <newren@gmail.com>
> >
> > Commit 66b209b86a ("merge-ort: implement CE_SKIP_WORKTREE handling with
> > conflicted entries", 2021-03-20) added some code for merge-ort to handle
> > conflicted and skip_worktree entries in general.  Included in this was
> > an ugly hack for dealing with present-despite-skipped entries and a
> > testcase (t6428.2) specific to that hack, since at that time users could
> > accidentally get files into that state when using a sparse checkout.
> >
> > However, with the merging of 82386b4496 ("Merge branch
> > 'en/present-despite-skipped'", 2022-03-09), that class of problems was
> > addressed globally and in a much cleaner way.  As such, the
> > present-despite-skipped hack in merge-ort is no longer needed and can
> > simply be removed.
> >
> > No additional testcase is needed here; t6428.2 was written to test the
> > necessary functionality and is being kept.  The fact that this test
> > continues to pass despite the code being removed shows that the extra
> > code is no longer necessary.
> >
> > Signed-off-by: Elijah Newren <newren@gmail.com>
> > ---
> >     merge-ort: remove code obsoleted by other changes
> >
> > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1302%2Fnewren%2Fnuke-present-despite-skipped-hack-v1
> > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1302/newren/nuke-present-despite-skipped-hack-v1
> > Pull-Request: https://github.com/git/git/pull/1302
> >
> >  merge-ort.c | 22 ++--------------------
> >  1 file changed, 2 insertions(+), 20 deletions(-)
>
> Nice!
>
> Since I have been in the `merge-ort` code quite a bit as of late, I deem
> myself familiar enough with the code to dare offering my ACK.

> What is _particularly_ nice is that this patch removes an `lstat()` call
> that was a bit of a concern for me when using `merge-ort` in a
> worktree-less scenario. After some reasoning about the code, it turned out
> that it is not hit in that use case, nevertheless it is much easier to
> reason about `lstat()` calls that simply are not in the code.