cache-tree: drop `the_repository` in `cache_tree_fully_valid()`

The function `cache_tree_fully_valid()` verifies whether the cache tree
owned by the index is valid or not. As part of that, the function checks
whether the objects referenced by the cache all exist. But because the
function has no repository available, it is using the object database of
`the_repository` instead.

We could of course adapt callers to pass in a repository as parameter
explicitly to get rid of this implicit dependency on global state. But
all of them pass the cache tree owned by a `struct index_state`, and
that structure already has a reference to its owning repository.

So instead, adapt the function to accept a `struct index_state`, which
ensures that callers will implicitly always pass the correct repository.
Adapt callers accordingly.

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

builtin/checkout.c

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 55e3a89..505d3f7 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -921,7 +921,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		}
 	}
 
-	if (!cache_tree_fully_valid(the_repository->index->cache_tree))
+	if (!cache_tree_fully_valid(the_repository->index))
 		cache_tree_update(the_repository->index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 
 	if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))

builtin/commit.c

diff --git a/builtin/commit.c b/builtin/commit.c
index 28f6174..840b6b4 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -484,7 +484,7 @@ static const char *prepare_index(const char **argv, const char *prefix,
 				       LOCK_DIE_ON_ERROR);
 		refresh_cache_or_die(refresh_flags);
 		if (the_repository->index->cache_changed
-		    || !cache_tree_fully_valid(the_repository->index->cache_tree))
+		    || !cache_tree_fully_valid(the_repository->index))
 			cache_tree_update(the_repository->index, WRITE_TREE_SILENT);
 		if (write_locked_index(the_repository->index, &index_lock,
 				       COMMIT_LOCK | SKIP_IF_UNCHANGED))

cache-tree.c

diff --git a/cache-tree.c b/cache-tree.c
index a220372..6103b3f 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -275,22 +275,29 @@ static void discard_unused_subtrees(struct cache_tree *it)
 	}
 }
 
-int cache_tree_fully_valid(struct cache_tree *it)
+static int cache_tree_fully_valid_recursive(struct object_database *odb,
+					    struct cache_tree *it)
 {
 	int i;
 	if (!it)
 		return 0;
 	if (it->entry_count < 0 ||
-	    !odb_has_object(the_repository->objects, &it->oid,
+	    !odb_has_object(odb, &it->oid,
 			    ODB_HAS_OBJECT_RECHECK_PACKED | ODB_HAS_OBJECT_FETCH_PROMISOR))
 		return 0;
 	for (i = 0; i < it->subtree_nr; i++) {
-		if (!cache_tree_fully_valid(it->down[i]->cache_tree))
+		if (!cache_tree_fully_valid_recursive(odb, it->down[i]->cache_tree))
 			return 0;
 	}
 	return 1;
 }
 
+int cache_tree_fully_valid(struct index_state *istate)
+{
+	return cache_tree_fully_valid_recursive(istate->repo->objects,
+						istate->cache_tree);
+}
+
 static int must_check_existence(const struct cache_entry *ce)
 {
 	return !(repo_has_promisor_remote(the_repository) && ce_skip_worktree(ce));
@@ -775,7 +782,7 @@ struct tree *write_in_core_index_as_tree(struct repository *repo,
 	int was_valid, ret;
 
 	was_valid = index_state->cache_tree &&
-		    cache_tree_fully_valid(index_state->cache_tree);
+		    cache_tree_fully_valid(index_state);
 
 	ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 	if (ret == WRITE_TREE_UNMERGED_INDEX) {
@@ -811,7 +818,7 @@ int write_index_as_tree(struct object_id *oid, struct index_state *index_state,
 
 	was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 		    index_state->cache_tree &&
-		    cache_tree_fully_valid(index_state->cache_tree);
+		    cache_tree_fully_valid(index_state);
 
 	ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 					   prefix);

cache-tree.h

diff --git a/cache-tree.h b/cache-tree.h
index f8bddae..4b3f60d 100644
--- a/cache-tree.h
+++ b/cache-tree.h
@@ -31,7 +31,7 @@ int cache_tree_subtree_pos(struct cache_tree *it, const char *path, int pathlen)
 void cache_tree_write(struct strbuf *, struct cache_tree *root);
 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
 
-int cache_tree_fully_valid(struct cache_tree *);
+int cache_tree_fully_valid(struct index_state *);
 int cache_tree_update(struct index_state *, int);
 int cache_tree_verify(struct repository *, struct index_state *);
 

sequencer.c

diff --git a/sequencer.c b/sequencer.c
index 65afd10..11a95c0 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -814,7 +814,7 @@ static int do_recursive_merge(struct repository *r,
 
 static struct object_id *get_cache_tree_oid(struct index_state *istate)
 {
-	if (!cache_tree_fully_valid(istate->cache_tree))
+	if (!cache_tree_fully_valid(istate))
 		if (cache_tree_update(istate, 0)) {
 			error(_("unable to update cache tree"));
 			return NULL;

sparse-index.c

diff --git a/sparse-index.c b/sparse-index.c
index c1fa231..3d77dad 100644
--- a/sparse-index.c
+++ b/sparse-index.c
@@ -228,7 +228,7 @@ int convert_to_sparse(struct index_state *istate, int flags)
 	if (index_has_unmerged_entries(istate))
 		return 0;
 
-	if (!cache_tree_fully_valid(istate->cache_tree)) {
+	if (!cache_tree_fully_valid(istate)) {
 		/* Clear and recompute the cache-tree */
 		cache_tree_free(&istate->cache_tree);
 

unpack-trees.c

diff --git a/unpack-trees.c b/unpack-trees.c
index 154d6d4..f6bb1e6 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -2086,7 +2086,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 			}
 
 			if (!o->skip_cache_tree_update &&
-			    !cache_tree_fully_valid(o->internal.result.cache_tree))
+			    !cache_tree_fully_valid(&o->internal.result))
 				cache_tree_update(&o->internal.result,
 						  WRITE_TREE_SILENT |
 						  WRITE_TREE_REPAIR);