fixup! sparse-index: make non-mixed reset sparse-aware

Fix an edge case where the cache tree is constructed improperly because invalid
cone-mode patterns are manually set in the sparse definition. Also fix test bug
(would not report error without `|| return 1`).

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

cache-tree.c

@@ -800,6 +800,17 @@ int write_index_as_tree(struct object_id *oid, struct index_state *index_state,
 	return ret;
 }
 
+static void prime_cache_tree_sparse_dir(struct repository *r,
+					struct cache_tree *it,
+					struct tree *tree,
+					struct strbuf *tree_path)
+{
+
+	oidcpy(&it->oid, &tree->object.oid);
+	it->entry_count = 1;
+	return;
+}
+
 static void prime_cache_tree_rec(struct repository *r,
 				 struct cache_tree *it,
 				 struct tree *tree,
@@ -812,21 +823,6 @@ static void prime_cache_tree_rec(struct repository *r,
 
 	oidcpy(&it->oid, &tree->object.oid);
 
-	/*
-	 * If this entry is outside the sparse-checkout cone, then it might be
-	 * a sparse directory entry. Check the index to ensure it is by looking
-	 * for an entry with the exact same name as the tree. If no matching sparse
-	 * entry is found, a staged or conflicted entry is preventing this
-	 * directory from collapsing to a sparse directory entry, so the cache
-	 * tree expansion should continue.
-	 */
-	if (r->index->sparse_index &&
-	    !path_in_cone_modesparse_checkout(tree_path->buf, r->index) &&
-	    index_name_pos(r->index, tree_path->buf, tree_path->len) >= 0) {
-		it->entry_count = 1;
-		return;
-	}
-
 	init_tree_desc(&desc, tree->buffer, tree->size);
 	cnt = 0;
 	while (tree_entry(&desc, &entry)) {
@@ -846,7 +842,18 @@ static void prime_cache_tree_rec(struct repository *r,
 			strbuf_add(&subtree_path, entry.path, entry.pathlen);
 			strbuf_addch(&subtree_path, '/');
 
-			prime_cache_tree_rec(r, sub->cache_tree, subtree, &subtree_path);
+			/*
+			* If a sparse index is in use, the directory being processed may be
+			* sparse. To confirm that, we can check whether an entry with that
+			* exact name exists in the index. If it does, the created subtree
+			* should be sparse. Otherwise, cache tree expansion should continue
+			* as normal.
+			*/
+			if (r->index->sparse_index &&
+			    index_entry_exists(r->index, subtree_path.buf, subtree_path.len))
+				prime_cache_tree_sparse_dir(r, sub->cache_tree, subtree, &subtree_path);
+			else
+				prime_cache_tree_rec(r, sub->cache_tree, subtree, &subtree_path);
 			cnt += sub->cache_tree->entry_count;
 		}
 	}

cache.h

@@ -833,6 +833,16 @@ struct cache_entry *index_file_next_match(struct index_state *istate, struct cac
  */
 int index_name_pos(struct index_state *, const char *name, int namelen);
 
+/*
+ * Determines whether an entry with the given name exists within the
+ * given index. The return value is 1 if an exact match is found, otherwise
+ * it is 0. Note that, unlike index_name_pos, this function does not expand
+ * the index if it is sparse. If an item exists within the full index but it
+ * is contained within a sparse directory (and not in the sparse index), 0 is
+ * returned.
+ */
+int index_entry_exists(struct index_state *, const char *name, int namelen);
+
 /*
  * Some functions return the negative complement of an insert position when a
  * precise match was not found but a position was found where the entry would

read-cache.c

@@ -564,7 +564,10 @@ int cache_name_stage_compare(const char *name1, int len1, int stage1, const char
 	return 0;
 }
 
-static int index_name_stage_pos(struct index_state *istate, const char *name, int namelen, int stage)
+static int index_name_stage_pos(struct index_state *istate,
+				const char *name, int namelen,
+				int stage,
+				int search_sparse)
 {
 	int first, last;
 
@@ -583,7 +586,7 @@ static int index_name_stage_pos(struct index_state *istate, const char *name, in
 		first = next+1;
 	}
 
-	if (istate->sparse_index &&
+	if (search_sparse && istate->sparse_index &&
 	    first > 0) {
 		/* Note: first <= istate->cache_nr */
 		struct cache_entry *ce = istate->cache[first - 1];
@@ -599,7 +602,7 @@ static int index_name_stage_pos(struct index_state *istate, const char *name, in
 		    ce_namelen(ce) < namelen &&
 		    !strncmp(name, ce->name, ce_namelen(ce))) {
 			ensure_full_index(istate);
-			return index_name_stage_pos(istate, name, namelen, stage);
+			return index_name_stage_pos(istate, name, namelen, stage, search_sparse);
 		}
 	}
 
@@ -608,7 +611,12 @@ static int index_name_stage_pos(struct index_state *istate, const char *name, in
 
 int index_name_pos(struct index_state *istate, const char *name, int namelen)
 {
-	return index_name_stage_pos(istate, name, namelen, 0);
+	return index_name_stage_pos(istate, name, namelen, 0, 1);
+}
+
+int index_entry_exists(struct index_state *istate, const char *name, int namelen)
+{
+	return index_name_stage_pos(istate, name, namelen, 0, 0) >= 0;
 }
 
 int remove_index_entry_at(struct index_state *istate, int pos)
@@ -1235,7 +1243,7 @@ static int has_dir_name(struct index_state *istate,
 			 */
 		}
 
-		pos = index_name_stage_pos(istate, name, len, stage);
+		pos = index_name_stage_pos(istate, name, len, stage, 1);
 		if (pos >= 0) {
 			/*
 			 * Found one, but not so fast.  This could
@@ -1332,7 +1340,7 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
 		strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0)
 		pos = index_pos_to_insert_pos(istate->cache_nr);
 	else
-		pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
+		pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce), 1);
 
 	/*
 	 * Cache tree path should be invalidated only after index_name_stage_pos,
@@ -1374,7 +1382,7 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
 		if (!ok_to_replace)
 			return error(_("'%s' appears as both a file and as a directory"),
 				     ce->name);
-		pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
+		pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce), 1);
 		pos = -pos-1;
 	}
 	return pos + 1;

t/t1092-sparse-checkout-compatibility.sh

@@ -1050,7 +1050,7 @@ test_expect_success 'sparse-index is not expanded' '
 	do
 		echo >>sparse-index/README.md &&
 		ensure_not_expanded reset --mixed $ref
-		ensure_not_expanded reset --hard $ref
+		ensure_not_expanded reset --hard $ref || return 1
 	done &&
 
 	ensure_not_expanded reset --hard update-deep &&