[PATCH v3 1/9] cache-tree: clean up cache_tree_update()

From: Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date: Jan 23, 2021, 19:58 UTC
Message-ID: <bdc8ecca3d2a2fbdb1d8bf10222382c14986aa56.1611431899.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.839.v3.git.1611431899.gitgitgadget@gmail.com>

From: Derrick Stolee <dstolee@microsoft.com>

Make the method safer by allocating a cache_tree member for the given index_state if it is not already present. This is preferrable to a BUG() statement or returning with an error because future callers will want to populate an empty cache-tree using this method.

Callers can also remove their conditional allocations of cache_tree.

Also drop local variables that can be found directly from the 'istate' parameter.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 builtin/checkout.c |  3 ---
 cache-tree.c       | 17 +++++++++--------
 sequencer.c        |  3 ---
 unpack-trees.c     |  2 --
 4 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index c9ba23c2794..2d6550bc3c8 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -821,9 +821,6 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		}
 	}
 
-	if (!active_cache_tree)
-		active_cache_tree = cache_tree();
-
 	if (!cache_tree_fully_valid(active_cache_tree))
 		cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
 
diff --git a/cache-tree.c b/cache-tree.c
index 3f1a8d4f1b7..60b6aefbf51 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -436,16 +436,20 @@ static int update_one(struct cache_tree *it,
 
 int cache_tree_update(struct index_state *istate, int flags)
 {
-	struct cache_tree *it = istate->cache_tree;
-	struct cache_entry **cache = istate->cache;
-	int entries = istate->cache_nr;
-	int skip, i = verify_cache(cache, entries, flags);
+	int skip, i;
+
+	i = verify_cache(istate->cache, istate->cache_nr, flags);
 
 	if (i)
 		return i;
+
+	if (!istate->cache_tree)
+		istate->cache_tree = cache_tree();
+
 	trace_performance_enter();
 	trace2_region_enter("cache_tree", "update", the_repository);
-	i = update_one(it, cache, entries, "", 0, &skip, flags);
+	i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
+		       "", 0, &skip, flags);
 	trace2_region_leave("cache_tree", "update", the_repository);
 	trace_performance_leave("cache_tree_update");
 	if (i < 0)
@@ -635,9 +639,6 @@ static int write_index_as_tree_internal(struct object_id *oid,
 		cache_tree_valid = 0;
 	}
 
-	if (!index_state->cache_tree)
-		index_state->cache_tree = cache_tree();
-
 	if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 		return WRITE_TREE_UNMERGED_INDEX;
 
diff --git a/sequencer.c b/sequencer.c
index 8909a467700..aa3e4c81cf0 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -679,9 +679,6 @@ static int do_recursive_merge(struct repository *r,
 
 static struct object_id *get_cache_tree_oid(struct index_state *istate)
 {
-	if (!istate->cache_tree)
-		istate->cache_tree = cache_tree();
-
 	if (!cache_tree_fully_valid(istate->cache_tree))
 		if (cache_tree_update(istate, 0)) {
 			error(_("unable to update cache tree"));
diff --git a/unpack-trees.c b/unpack-trees.c
index af6e9b9c2fd..a810b79657e 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1726,8 +1726,6 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 		if (!ret) {
 			if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0))
 				cache_tree_verify(the_repository, &o->result);
-			if (!o->result.cache_tree)
-				o->result.cache_tree = cache_tree();
 			if (!cache_tree_fully_valid(o->result.cache_tree))
 				cache_tree_update(&o->result,
 						  WRITE_TREE_SILENT |

-- 
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