Merge branch 'ab/cache-api-cleanup'

Code clean-up to tighten the use of in-core index in the API.

* ab/cache-api-cleanup:
  cache API: add a "INDEX_STATE_INIT" macro/function, add release_index()
  read-cache.c: refactor set_new_index_sparsity() for subsequent commit
  sparse-index API: BUG() out on NULL ensure_full_index()
  sparse-index.c: expand_to_path() can assume non-NULL "istate"
  builtin/difftool.c: { 0 }-initialize rather than using memset()

4 files changed, 11 insertions, 12 deletions

diff --git a/builtin/difftool.c b/builtin/difftool.c
index d9b76226f6..758e7bd3b6 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -361,7 +361,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 	struct hashmap symlinks2 = HASHMAP_INIT(pair_cmp, NULL);
 	struct hashmap_iter iter;
 	struct pair_entry *entry;
-	struct index_state wtindex;
+	struct index_state wtindex = INDEX_STATE_INIT;
 	struct checkout lstate, rstate;
 	int err = 0;
 	struct child_process cmd = CHILD_PROCESS_INIT;
@@ -387,8 +387,6 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 	mkdir(ldir.buf, 0700);
 	mkdir(rdir.buf, 0700);
 
-	memset(&wtindex, 0, sizeof(wtindex));
-
 	memset(&lstate, 0, sizeof(lstate));
 	lstate.base_dir = lbase_dir = xstrdup(ldir.buf);
 	lstate.base_dir_len = ldir.len;
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 58a22503f0..dc332c6d05 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -217,6 +217,7 @@ static int update_working_directory(struct pattern_list *pl)
 	o.head_idx = -1;
 	o.src_index = r->index;
 	o.dst_index = r->index;
+	index_state_init(&o.result);
 	o.skip_sparse_checkout = 0;
 	o.pl = pl;
 
diff --git a/builtin/stash.c b/builtin/stash.c
index bb0fd86143..a5f13fb1e9 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -1137,7 +1137,7 @@ static int save_untracked_files(struct stash_info *info, struct strbuf *msg,
 	int ret = 0;
 	struct strbuf untracked_msg = STRBUF_INIT;
 	struct child_process cp_upd_index = CHILD_PROCESS_INIT;
-	struct index_state istate = { NULL };
+	struct index_state istate = INDEX_STATE_INIT;
 
 	cp_upd_index.git_cmd = 1;
 	strvec_pushl(&cp_upd_index.args, "update-index", "-z", "--add",
@@ -1165,7 +1165,7 @@ static int save_untracked_files(struct stash_info *info, struct strbuf *msg,
 	}
 
 done:
-	discard_index(&istate);
+	release_index(&istate);
 	strbuf_release(&untracked_msg);
 	remove_path(stash_index_path.buf);
 	return ret;
@@ -1176,7 +1176,7 @@ static int stash_staged(struct stash_info *info, struct strbuf *out_patch,
 {
 	int ret = 0;
 	struct child_process cp_diff_tree = CHILD_PROCESS_INIT;
-	struct index_state istate = { NULL };
+	struct index_state istate = INDEX_STATE_INIT;
 
 	if (write_index_as_tree(&info->w_tree, &istate, the_repository->index_file,
 				0, NULL)) {
@@ -1199,7 +1199,7 @@ static int stash_staged(struct stash_info *info, struct strbuf *out_patch,
 	}
 
 done:
-	discard_index(&istate);
+	release_index(&istate);
 	return ret;
 }
 
@@ -1209,7 +1209,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	int ret = 0;
 	struct child_process cp_read_tree = CHILD_PROCESS_INIT;
 	struct child_process cp_diff_tree = CHILD_PROCESS_INIT;
-	struct index_state istate = { NULL };
+	struct index_state istate = INDEX_STATE_INIT;
 	char *old_index_env = NULL, *old_repo_index_file;
 
 	remove_path(stash_index_path.buf);
@@ -1260,7 +1260,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	}
 
 done:
-	discard_index(&istate);
+	release_index(&istate);
 	remove_path(stash_index_path.buf);
 	return ret;
 }
@@ -1271,7 +1271,7 @@ static int stash_working_tree(struct stash_info *info, const struct pathspec *ps
 	struct rev_info rev;
 	struct child_process cp_upd_index = CHILD_PROCESS_INIT;
 	struct strbuf diff_output = STRBUF_INIT;
-	struct index_state istate = { NULL };
+	struct index_state istate = INDEX_STATE_INIT;
 
 	init_revisions(&rev, NULL);
 	copy_pathspec(&rev.prune_data, ps);
@@ -1319,7 +1319,7 @@ static int stash_working_tree(struct stash_info *info, const struct pathspec *ps
 	}
 
 done:
-	discard_index(&istate);
+	release_index(&istate);
 	release_revisions(&rev);
 	strbuf_release(&diff_output);
 	remove_path(stash_index_path.buf);
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 591d659fae..311d6e9075 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -923,7 +923,7 @@ static int unlock_worktree(int ac, const char **av, const char *prefix)
 
 static void validate_no_submodules(const struct worktree *wt)
 {
-	struct index_state istate = { NULL };
+	struct index_state istate = INDEX_STATE_INIT;
 	struct strbuf path = STRBUF_INIT;
 	int i, found_submodules = 0;