repository: initialize index in `repo_init()`

When Git starts, one of the first things it will do is to call
`initialize_the_repository()`. This function sets up both the global
`the_repository` and `the_index` variables as required. Part of that
setup is also to set `the_repository.index = &the_index` so that the
index can be accessed via the repository.

When calling `repo_init()` on a repository though we set the complete
struct to all-zeroes, which will also cause us to unset the `index`
pointer. And as we don't re-initialize the index in that function, we
will end up with a `NULL` pointer here.

This has been fine until now becaues this function is only used to
create a new repository. git-init(1) does not access the index at all
after initializing the repository, whereas git-checkout(1) only uses
`the_index` directly. We are about to remove `the_index` though, which
will uncover this partially-initialized repository structure.

Refactor the code and create a common `initialize_repository()` function
that gets called from `repo_init()` and `initialize_the_repository()`.
This function sets up both the repository and the index as required.
Like this, we can easily special-case when `repo_init()` gets called
with `the_repository`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/repository.c b/repository.c
index e15b416944dfb21f752093fab777fabf475d4f31..d64d15d952879c7ced1183e7b8109f40dc1e1d5a 100644 (file)
--- a/repository.c
+++ b/repository.c
@@ -25,17 +25,20 @@ static struct repository the_repo;
 struct repository *the_repository;
 struct index_state the_index;
 
+static void initialize_repository(struct repository *repo,
+                                 struct index_state *index)
+{
+       repo->index = index;
+       repo->objects = raw_object_store_new();
+       repo->remote_state = remote_state_new();
+       repo->parsed_objects = parsed_object_pool_new();
+       index_state_init(index, repo);
+}
+
 void initialize_the_repository(void)
 {
        the_repository = &the_repo;
-
-       the_repo.index = &the_index;
-       the_repo.objects = raw_object_store_new();
-       the_repo.remote_state = remote_state_new();
-       the_repo.parsed_objects = parsed_object_pool_new();
-
-       index_state_init(&the_index, the_repository);
-
+       initialize_repository(the_repository, &the_index);
        repo_set_hash_algo(&the_repo, GIT_HASH_SHA1);
 }
 
@@ -188,9 +191,12 @@ int repo_init(struct repository *repo,
        struct repository_format format = REPOSITORY_FORMAT_INIT;
        memset(repo, 0, sizeof(*repo));
 
-       repo->objects = raw_object_store_new();
-       repo->parsed_objects = parsed_object_pool_new();
-       repo->remote_state = remote_state_new();
+       if (repo == the_repository) {
+               initialize_repository(the_repository, &the_index);
+       } else {
+               ALLOC_ARRAY(repo->index, 1);
+               initialize_repository(repo, repo->index);
+       }
 
        if (repo_init_gitdir(repo, gitdir))
                goto error;