cache-tree: allow writing in-memory index as tree

The function `write_in_core_index_as_tree()` takes a repository and writes its index into a tree object. What this function cannot do though is to take an _arbitrary_ in-memory index. Introduce a new `struct index_state` parameter so that the caller can pass a different index than the one belonging to the repository. This will be used in a subsequent commit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Mar 2, 2026 at 13:13 UTC a021e4f92cbacdb028b3efa49f619b076e72c9a6
3 files changed +6 -4
builtin/checkout.c
+2 -1
index a8863277f2..f8b3a7b08c 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -891,7 +891,8 @@ static int merge_working_tree(const struct checkout_opts *opts, 0); init_ui_merge_options(&o, the_repository); o.verbosity = 0; - work = write_in_core_index_as_tree(the_repository); + work = write_in_core_index_as_tree(the_repository, + the_repository->index); ret = reset_tree(new_tree, opts, 1,
cache-tree.c
+2 -2
index 16c3a36b48..60bcc07c3b 100644 --- a/cache-tree.c +++ b/cache-tree.c @@ -723,11 +723,11 @@ static int write_index_as_tree_internal(struct object_id *oid, return 0; } -struct tree* write_in_core_index_as_tree(struct repository *repo) { +struct tree *write_in_core_index_as_tree(struct repository *repo, + struct index_state *index_state) { struct object_id o; int was_valid, ret; - struct index_state *index_state = repo->index; was_valid = index_state->cache_tree && cache_tree_fully_valid(index_state->cache_tree);
cache-tree.h
+2 -1
index b82c4963e7..f8bddae523 100644 --- a/cache-tree.h +++ b/cache-tree.h @@ -47,7 +47,8 @@ int cache_tree_verify(struct repository *, struct index_state *); #define WRITE_TREE_UNMERGED_INDEX (-2) #define WRITE_TREE_PREFIX_ERROR (-3) -struct tree* write_in_core_index_as_tree(struct repository *repo); +struct tree *write_in_core_index_as_tree(struct repository *repo, + struct index_state *index_state); int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix); void prime_cache_tree(struct repository *, struct index_state *, struct tree *);