Re: [PATCH v5] merge-tree: add -X strategy option
- From
- Phillip Wood <phillip.wood123@gmail.com>
- Date
- Sep 18, 2023, 09:53 UTC
- Message-ID
- <67638fd7-ad63-4e20-87e1-bef121fef197@gmail.com>
- In-Reply-To
- <pull.1565.v5.git.1694853437494.gitgitgadget@gmail.com>
On 16/09/2023 09:37, Izzy via GitGitGadget wrote:
> From: Tang Yuyi <winglovet@gmail.com> > > Add merge strategy option to produce more customizable merge result such > as automatically resolving conflicts.
I think adding a merge strategy option to merge-tree is a good idea, but have you tested this with anything apart from -Xours or -Xtheirs? It looks to me like those are the only two that this patch supports. If you look at parse_merge_opt() in merge-recursive.c you will see that there are many other options. In order to support all the merge options I think this patch needs a bit of refactoring.
Show 11 quoted lines
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c > index 0de42aecf4b..97d0fe6c952 100644 > --- a/builtin/merge-tree.c > +++ b/builtin/merge-tree.c > static int real_merge(struct merge_tree_options *o, > @@ -439,6 +441,8 @@ static int real_merge(struct merge_tree_options *o, > > init_merge_options(&opt, the_repository); > > + opt.recursive_variant = o->merge_options.recursive_variant; > +
Rather that copying across individual members I think you should initialize o->merge_options properly in cmd_merge_tree() by calling init_merge_options() and then use o->merge_options instead of "opt" in this function. That way all the strategy options will be supported.
Show 21 quoted lines
> opt.show_rename_progress = 0;
>
> opt.branch1 = branch1;
> @@ -513,6 +517,7 @@ static int real_merge(struct merge_tree_options *o,
> int cmd_merge_tree(int argc, const char **argv, const char *prefix)
> {
> struct merge_tree_options o = { .show_messages = -1 };
> + struct strvec xopts = STRVEC_INIT;
> int expected_remaining_argc;
> int original_argc;
> const char *merge_base = NULL;
> @@ -548,6 +553,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
> &merge_base,
> N_("commit"),
> N_("specify a merge-base for the merge")),
> + OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
> + N_("option for selected merge strategy")),
> OPT_END()
> };
>
> @@ -556,6 +563,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)You should add
init_merge_options(&o.merge_options);
here to ensure it is properly initialized.
> argc = parse_options(argc, argv, prefix, mt_options, > merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
This is the right place to call parse_merge_opt() but I think we should first check that the user has requested a real merge rather than a trivial merge.
if (xopts.nr && o.mode == MODE_TRIVIAL)
die(_("--trivial-merge is incompatible with all other options"));Otherwise if the user passes in invalid strategy option to a trivial merge they'll get an error about an invalid strategy option rather than being told --strategy-option is not supported with --trivial-merge.
Ideally there would be a preparatory patch that moves the switch statement that is below the "if(o.use_stdin)" block up to this point so we'd always have set o.mode before checking if it is a trivial merge. (I think you'd to change the code slightly when it is moved to add a check for o.use_stdin)
Best Wishes
Phillip
Show 57 quoted lines
> + for (int x = 0; x < xopts.nr; x++)
> + if (parse_merge_opt(&o.merge_options, xopts.v[x]))
> + die(_("unknown strategy option: -X%s"), xopts.v[x]);
> +
> /* Handle --stdin */
> if (o.use_stdin) {
> struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..b2c8a43fce3 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
> git branch side1 &&
> git branch side2 &&
> git branch side3 &&
> + git branch side4 &&
>
> git checkout side1 &&
> test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
> test_tick &&
> git commit -m rename-numbers &&
>
> + git checkout side4 &&
> + test_write_lines 0 1 2 3 4 5 >numbers &&
> + echo yo >greeting &&
> + git add numbers greeting &&
> + test_tick &&
> + git commit -m other-content-modifications &&
> +
> git switch --orphan unrelated &&
> >something-else &&
> git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
> test_cmp expect actual
> '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> + git checkout side1^0 &&
> +
> + # make sure merge conflict exists
> + test_must_fail git merge side4 &&
> + git merge --abort &&
> +
> + git merge -X ours side4 &&
> + git rev-parse HEAD^{tree} >expected &&
> +
> + git merge-tree -X ours side1 side4 >actual &&
> +
> + test_cmp expected actual
> +'
> +
> test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
> # Mis-spell with single "s" instead of double "s"
> test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb