[PATCH 17/27] dir.c: accept a directory as part of cone-mode patterns

From: Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date: Jan 25, 2021, 17:42 UTC
Message-ID: <036653cac368c6c04b439f5352d70a5dcc3c5feb.1611596534.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.847.git.1611596533.gitgitgadget@gmail.com>

From: Derrick Stolee <dstolee@microsoft.com>

When we have sparse directory entries in the index, we want to compare that directory against sparse-checkout patterns. Those pattern matching algorithms are built expecting a file path, not a directory path. This is especially important in the "cone mode" patterns which will match files that exist within the "parent directories" as well as the recursive directory matches.

If path_matches_pattern_list() is given a directory, we can add a bogus filename ("-") to the directory and get the same results as before, assuming we are in cone mode. Since sparse index requires cone mode patterns, this is an acceptable assumption.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 dir.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/dir.c b/dir.c
index ad6eb033cb1..c786fa98d0e 100644
--- a/dir.c
+++ b/dir.c
@@ -1384,6 +1384,11 @@ enum pattern_match_result path_matches_pattern_list(
 	strbuf_addch(&parent_pathname, '/');
 	strbuf_add(&parent_pathname, pathname, pathlen);
 
+	/* Directory requests should be added as if they are a file */
+	if (parent_pathname.len > 1 &&
+	    parent_pathname.buf[parent_pathname.len - 1] == '/')
+		strbuf_add(&parent_pathname, "-", 1);
+
 	if (hashmap_contains_path(&pl->recursive_hashmap,
 				  &parent_pathname)) {
 		result = MATCHED_RECURSIVE;

-- 
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