On Tue, May 10, 2022 at 4:32 PM Victoria Dye via GitGitGadget
<gitgitgadget@xxxxxxxxx> wrote:
>
> From: Victoria Dye <vdye@xxxxxxxxxx>
>
> Update 'stash' to use 'merge_ort_nonrecursive()' to apply a stash to the
> current working tree. When 'git stash apply' was converted from its shell
> script implementation to a builtin in 8a0fc8d19d (stash: convert apply to
> builtin, 2019-02-25), 'merge_recursive_generic()' was used to merge a stash
> into the working tree as part of 'git stash (apply|pop)'. However, with the
> single merge base used in 'do_apply_stash()', the commit wrapping done by
> 'merge_recursive_generic()' is not only unnecessary, but misleading (the
> *real* merge base is labeled "constructed merge base"). Therefore, a
> non-recursive merge of the working tree, stashed tree, and stash base tree
> is more appropriate.
>
> There are two options for a non-recursive merge-then-update-worktree
> function: 'merge_trees()' and 'merge_ort_nonrecursive()'. Use
> 'merge_ort_nonrecursive()' to align with the default merge strategy used by
> 'git merge' (6a5fb96672 (Change default merge backend from recursive to ort,
> 2021-08-04)) and, because merge-ort does not operate in-place on the index,
> avoid unnecessary index expansion. Update tests in 't1092' verifying index
> expansion for 'git stash' accordingly.
>
> Signed-off-by: Victoria Dye <vdye@xxxxxxxxxx>
> ---
> builtin/stash.c | 30 +++++++++++++++++++-----
> t/t1092-sparse-checkout-compatibility.sh | 4 ++--
> 2 files changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/builtin/stash.c b/builtin/stash.c
> index 1bfba532044..3fe549f7d3c 100644
> --- a/builtin/stash.c
> +++ b/builtin/stash.c
> @@ -7,6 +7,7 @@
> #include "cache-tree.h"
> #include "unpack-trees.h"
> #include "merge-recursive.h"
> +#include "merge-ort-wrappers.h"
> #include "strvec.h"
> #include "run-command.h"
> #include "dir.h"
> @@ -492,13 +493,13 @@ static void unstage_changes_unless_new(struct object_id *orig_tree)
> static int do_apply_stash(const char *prefix, struct stash_info *info,
> int index, int quiet)
> {
> - int ret;
> + int clean, ret;
> int has_index = index;
> struct merge_options o;
> struct object_id c_tree;
> struct object_id index_tree;
> - struct commit *result;
> - const struct object_id *bases[1];
> + struct tree *head, *merge, *merge_base;
> + struct lock_file lock = LOCK_INIT;
>
> read_cache_preload(NULL);
> if (refresh_and_write_cache(REFRESH_QUIET, 0, 0))
> @@ -541,6 +542,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
>
> o.branch1 = "Updated upstream";
> o.branch2 = "Stashed changes";
> + o.ancestor = "Stash base";
>
> if (oideq(&info->b_tree, &c_tree))
> o.branch1 = "Version stash was based on";
> @@ -551,10 +553,26 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
> if (o.verbosity >= 3)
> printf_ln(_("Merging %s with %s"), o.branch1, o.branch2);
>
> - bases[0] = &info->b_tree;
> + head = lookup_tree(o.repo, &c_tree);
> + merge = lookup_tree(o.repo, &info->w_tree);
> + merge_base = lookup_tree(o.repo, &info->b_tree);
> +
> + repo_hold_locked_index(o.repo, &lock, LOCK_DIE_ON_ERROR);
> + clean = merge_ort_nonrecursive(&o, head, merge, merge_base);
A very minor nit: I actually have a minor dislike for the
merge-ort-wrappers, but I included them in case people objected to the
slightly more verbose real API. I assumed it'd only be used to
convert existing calls to merge_trees() and merge_recursive(); in this
case you were converting a call to merge_recursive_generic(), so I
would have preferred using merge_incore_nonrecursive(). That might
have answered Jonathan's question better too when he saw the explicit
merge_switch_to_result() call. However, it's a minor point; I'm not
sure it's worth a re-roll.
This series looks good to me:
Reviewed-by: Elijah Newren <newren@xxxxxxxxx>
