1 files changed, 70 insertions, 32 deletions

diff --git a/sparse-index.c b/sparse-index.c
index affc4048f2..7b7ff79e04 100644
--- a/sparse-index.c
+++ b/sparse-index.c
@@ -33,19 +33,14 @@ static int convert_to_sparse_rec(struct index_state *istate,
 {
 	int i, can_convert = 1;
 	int start_converted = num_converted;
-	enum pattern_match_result match;
-	int dtype = DT_UNKNOWN;
 	struct strbuf child_path = STRBUF_INIT;
-	struct pattern_list *pl = istate->sparse_checkout_patterns;
 
 	/*
 	 * Is the current path outside of the sparse cone?
 	 * Then check if the region can be replaced by a sparse
 	 * directory entry (everything is sparse and merged).
 	 */
-	match = path_matches_pattern_list(ct_path, ct_pathlen,
-					  NULL, &dtype, pl, istate);
-	if (match != NOT_MATCHED)
+	if (path_in_sparse_checkout(ct_path, istate))
 		can_convert = 0;
 
 	for (i = start; can_convert && i < end; i++) {
@@ -116,46 +111,81 @@ int set_sparse_index_config(struct repository *repo, int enable)
 	return res;
 }
 
-int convert_to_sparse(struct index_state *istate)
+static int index_has_unmerged_entries(struct index_state *istate)
+{
+	int i;
+	for (i = 0; i < istate->cache_nr; i++) {
+		if (ce_stage(istate->cache[i]))
+			return 1;
+	}
+
+	return 0;
+}
+
+int convert_to_sparse(struct index_state *istate, int flags)
 {
 	int test_env;
-	if (istate->split_index || istate->sparse_index ||
+	if (istate->sparse_index || !istate->cache_nr ||
 	    !core_apply_sparse_checkout || !core_sparse_checkout_cone)
 		return 0;
 
 	if (!istate->repo)
 		istate->repo = the_repository;
 
+	if (!(flags & SPARSE_INDEX_MEMORY_ONLY)) {
+		/*
+		 * The sparse index is not (yet) integrated with a split index.
+		 */
+		if (istate->split_index)
+			return 0;
+		/*
+		 * The GIT_TEST_SPARSE_INDEX environment variable triggers the
+		 * index.sparse config variable to be on.
+		 */
+		test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
+		if (test_env >= 0)
+			set_sparse_index_config(istate->repo, test_env);
+
+		/*
+		 * Only convert to sparse if index.sparse is set.
+		 */
+		prepare_repo_settings(istate->repo);
+		if (!istate->repo->settings.sparse_index)
+			return 0;
+	}
+
+	if (init_sparse_checkout_patterns(istate))
+		return 0;
+
 	/*
-	 * The GIT_TEST_SPARSE_INDEX environment variable triggers the
-	 * index.sparse config variable to be on.
+	 * We need cone-mode patterns to use sparse-index. If a user edits
+	 * their sparse-checkout file manually, then we can detect during
+	 * parsing that they are not actually using cone-mode patterns and
+	 * hence we need to abort this conversion _without error_. Warnings
+	 * already exist in the pattern parsing to inform the user of their
+	 * bad patterns.
 	 */
-	test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
-	if (test_env >= 0)
-		set_sparse_index_config(istate->repo, test_env);
+	if (!istate->sparse_checkout_patterns->use_cone_patterns)
+		return 0;
 
 	/*
-	 * Only convert to sparse if index.sparse is set.
+	 * NEEDSWORK: If we have unmerged entries, then stay full.
+	 * Unmerged entries prevent the cache-tree extension from working.
 	 */
-	prepare_repo_settings(istate->repo);
-	if (!istate->repo->settings.sparse_index)
+	if (index_has_unmerged_entries(istate))
 		return 0;
 
-	if (!istate->sparse_checkout_patterns) {
-		istate->sparse_checkout_patterns = xcalloc(1, sizeof(struct pattern_list));
-		if (get_sparse_checkout_patterns(istate->sparse_checkout_patterns) < 0)
-			return 0;
-	}
-
-	if (!istate->sparse_checkout_patterns->use_cone_patterns) {
-		warning(_("attempting to use sparse-index without cone mode"));
-		return -1;
-	}
-
-	if (cache_tree_update(istate, 0)) {
-		warning(_("unable to update cache-tree, staying full"));
-		return -1;
-	}
+	/* Clear and recompute the cache-tree */
+	cache_tree_free(&istate->cache_tree);
+	/*
+	 * Silently return if there is a problem with the cache tree update,
+	 * which might just be due to a conflict state in some entry.
+	 *
+	 * This might create new tree objects, so be sure to use
+	 * WRITE_TREE_MISSING_OK.
+	 */
+	if (cache_tree_update(istate, WRITE_TREE_MISSING_OK))
+		return 0;
 
 	remove_fsmonitor(istate);
 
@@ -168,6 +198,10 @@ int convert_to_sparse(struct index_state *istate)
 	cache_tree_free(&istate->cache_tree);
 	cache_tree_update(istate, 0);
 
+	istate->fsmonitor_has_run_once = 0;
+	FREE_AND_NULL(istate->fsmonitor_dirty);
+	FREE_AND_NULL(istate->fsmonitor_last_update);
+
 	istate->sparse_index = 1;
 	trace2_region_leave("index", "convert_to_sparse", istate->repo);
 	return 0;
@@ -195,7 +229,7 @@ static int add_path_to_index(const struct object_id *oid,
 	strbuf_addstr(base, path);
 
 	ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
-	ce->ce_flags |= CE_SKIP_WORKTREE;
+	ce->ce_flags |= CE_SKIP_WORKTREE | CE_EXTENDED;
 	set_index_entry(istate, istate->cache_nr++, ce);
 
 	strbuf_setlen(base, len);
@@ -259,11 +293,15 @@ void ensure_full_index(struct index_state *istate)
 
 	/* Copy back into original index. */
 	memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
+	memcpy(&istate->dir_hash, &full->dir_hash, sizeof(full->dir_hash));
 	istate->sparse_index = 0;
 	free(istate->cache);
 	istate->cache = full->cache;
 	istate->cache_nr = full->cache_nr;
 	istate->cache_alloc = full->cache_alloc;
+	istate->fsmonitor_has_run_once = 0;
+	FREE_AND_NULL(istate->fsmonitor_dirty);
+	FREE_AND_NULL(istate->fsmonitor_last_update);
 
 	strbuf_release(&base);
 	free(full);