On 12/14/2020 11:21 AM, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <newren@xxxxxxxxx>
>
> Implement rename/delete conflicts, i.e. one side renames a file and the
> other deletes the file. This code replaces the following from
> merge-recurisve.c:
>
> * the code relevant to RENAME_DELETE in process_renames()
> * the RENAME_DELETE case of process_entry()
> * handle_rename_delete()
>
> Also, there is some shared code from merge-recursive.c for multiple
> different rename cases which we will no longer need for this case (or
> other rename cases):
>
> * handle_change_delete()
> * setup_rename_conflict_info()
>
> The consolidation of five separate codepaths into one is made possible
> by a change in design: process_renames() tweaks the conflict_info
> entries within opt->priv->paths such that process_entry() can then
> handle all the non-rename conflict types (directory/file, modify/delete,
> etc.) orthogonally. This means we're much less likely to miss special
> implementation of some kind of combination of conflict types (see
> commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
> 2020-11-18), especially commit ef52778708 ("merge tests: expect improved
> directory/file conflict handling in ort", 2020-10-26) for more details).
> That, together with letting worktree/index updating be handled
> orthogonally in the merge_switch_to_result() function, dramatically
> simplifies the code for various special rename cases.
>
> To be fair, there is a _slight_ tweak to process_entry() here, because
> rename/delete cases will also trigger the modify/delete codepath.
> However, we only want a modify/delete message to be printed for a
> rename/delete conflict if there is a content change in the renamed file
> in addition to the rename. So process_renames() and process_entry()
> aren't quite fully orthogonal, but they are pretty close.
Thanks for adding this warning about the change to process_entry().
> @@ -657,6 +657,7 @@ static int process_renames(struct merge_options *opt,
> unsigned int old_sidemask;
> int target_index, other_source_index;
> int source_deleted, collision, type_changed;
> + const char *rename_branch = NULL, *delete_branch = NULL;
Ah, here they are!
> + if (source_deleted) {
> + if (target_index == 1) {
> + rename_branch = opt->branch1;
> + delete_branch = opt->branch2;
> + } else {
> + rename_branch = opt->branch2;
> + delete_branch = opt->branch1;
> + }
> }
>
> assert(source_deleted || oldinfo->filemask & old_sidemask);
> @@ -838,13 +847,26 @@ static int process_renames(struct merge_options *opt,
> "to %s in %s, but deleted in %s."),
> oldpath, newpath, rename_branch, delete_branch);
This context line is the previous use of rename_branch and delete_branch.
Perhaps the declarations, initialization, and first-use here are worth
their own patch?
> } else {
> + /*
> + * a few different cases...start by copying the
> + * existing stage(s) from oldinfo over the newinfo
> + * and update the pathname(s).
> + */
> + memcpy(&newinfo->stages[0], &oldinfo->stages[0],
> + sizeof(newinfo->stages[0]));
> + newinfo->filemask |= (1 << MERGE_BASE);
> + newinfo->pathnames[0] = oldpath;
> if (type_changed) {
> /* rename vs. typechange */
> die("Not yet implemented");
> } else if (source_deleted) {
> /* rename/delete */
> + newinfo->path_conflict = 1;
> + path_msg(opt, newpath, 0,
> + _("CONFLICT (rename/delete): %s renamed"
> + " to %s in %s, but deleted in %s."),
> + oldpath, newpath,
> + rename_branch, delete_branch);
Since the primary purpose of rename_branch and delete_branch appears to
be for these error messages, then likely the previous error message about
a rename/delete should just be promoted into this patch instead of the
previous.
In fact, the error messages are the exact same, but with slightly different
lines due to wrapping:
path_msg(opt, newpath, 0,
_("CONFLICT (rename/delete): %s renamed "
"to %s in %s, but deleted in %s."),
oldpath, newpath, rename_branch, delete_branch);
and
path_msg(opt, newpath, 0,
_("CONFLICT (rename/delete): %s renamed"
" to %s in %s, but deleted in %s."),
oldpath, newpath,
rename_branch, delete_branch);
I wonder if there is a way to group these together? Perhaps the nested
if/else if/else blocks could store a "conflict state" value that says
which CONFLICT message to print after the complicated branching is done.
Alternatively, this message appears to be written in the following case:
source_deleted && !type_changed
your if/else if/else block could be rearranged as follows:
if (collision && !source_deleted)
/* collision: rename/add or rename/rename(2to1) */
else if (!type_change && source_deleted)
/* rename/delete or rename/add/delete or rename/rename(2to1)/delete */
else if (!collision)
/* a few different cases */
Of course, the thing I am missing is that copy of oldinfo->stages[0] into
newinfo->stages[0] along with changes to the filemask and pathnames! That
is likely why you need the two different markers, because the cases truly
are different in that subtle way.
> /* normal rename */
> die("Not yet implemented");
> @@ -1380,12 +1402,21 @@ static void process_entry(struct merge_options *opt,
> modify_branch = (side == 1) ? opt->branch1 : opt->branch2;
> delete_branch = (side == 1) ? opt->branch2 : opt->branch1;
>
> - path_msg(opt, path, 0,
> - _("CONFLICT (modify/delete): %s deleted in %s "
> - "and modified in %s. Version %s of %s left "
> - "in tree."),
> - path, delete_branch, modify_branch,
> - modify_branch, path);
> + if (ci->path_conflict &&
> + oideq(&ci->stages[0].oid, &ci->stages[side].oid)) {
> + /*
> + * This came from a rename/delete; no action to take,
> + * but avoid printing "modify/delete" conflict notice
> + * since the contents were not modified.
> + */
> + } else {
> + path_msg(opt, path, 0,
> + _("CONFLICT (modify/delete): %s deleted in %s "
> + "and modified in %s. Version %s of %s left "
> + "in tree."),
> + path, delete_branch, modify_branch,
> + modify_branch, path);
> + }
Thanks,
-Stolee
