Derrick Stolee wrote:

On 5/10/2023 4:30 PM, Felipe Contreras wrote:

quoted

Derrick Stolee via GitGitGadget wrote:

quoted

From: Derrick Stolee <redacted>

The 'git merge-tree' command handles creating root trees for merges
without using the worktree. This is a critical operation in many Git
hosts, as they typically store bare repositories.

This builtin does not load the default Git config, which can have
several important ramifications.

For the record, I had already sent a better version of this patch almost 2
years ago [1], not just for `git merge-tree`, but other commands as well.

The obvious fix was completely ignored by the maintainer.

The reason why it should be git_xmerge_config and not git_default_config, is
that merge.conflictstyle would not be parsed if you call git_default_config.

As mentioned by Elijah in a different thread, the merge machinery loads
the merge config as needed. I confirmed by creating this test, which I
may submit as an independent patch:

I wrote my patches before Elijah wrote the real merge implementation, and in
his function he does `init_merge_options()`, which eventually calls
`git_config(git_xmerge_config, NULL)`.

But if `git_config()` is already called, you shouldn't need to add yet another
`git_config()` call.

The problem is that he added `init_merge_options()` *after* the
`get_merge_parent()` calls, that's why the configuration is ignored.

If we move `init_merge_options()` to the right place, the problem is fixed:

--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c

@@ -424,6 +424,8 @@ static int real_merge(struct merge_tree_options *o,
 	struct merge_result result = { 0 };
 	int show_messages = o->show_messages;
 
+	init_merge_options(&opt, the_repository);
+
 	parent1 = get_merge_parent(branch1);
 	if (!parent1)
 		help_unknown_ref(branch1, "merge-tree",

@@ -434,8 +436,6 @@ static int real_merge(struct merge_tree_options *o,
 		help_unknown_ref(branch2, "merge-tree",
 				 _("not something we can merge"));
 
-	init_merge_options(&opt, the_repository);
-
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;

I ran your test case, and it passes.

I sent a patch for that here:

https://lore.kernel.org/git/20230511215608.1297686-1-felipe.contreras@gmail.com/ (local)

This is a more proper fix because a) it doesn't add any new line of code, b) it
doesn't add a new include, and c) it doesn't call `git_config()` twice.

Cheers.

-- 
Felipe Contreras