The way match_pathspec_item() handles names and pathspecs with trailing
slash characters, in conjunction with special options like
DO_MATCH_DIRECTORY and DO_MATCH_LEADING_PATHSPEC were non-obvious, and
broken until this patch series. Add a table in a comment explaining the
intent of how these work.
Signed-off-by: Elijah Newren <newren@xxxxxxxxx>
---
dir.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/dir.c b/dir.c
index 47c0a99cb5..3b2fe1701c 100644
--- a/dir.c
+++ b/dir.c
@@ -276,16 +276,27 @@ static int do_read_blob(const struct object_id *oid, struct oid_stat *oid_stat,
#define DO_MATCH_LEADING_PATHSPEC (1<<2)
/*
- * Does 'match' match the given name?
- * A match is found if
+ * Does the given pathspec match the given name? A match is found if
*
- * (1) the 'match' string is leading directory of 'name', or
- * (2) the 'match' string is a wildcard and matches 'name', or
- * (3) the 'match' string is exactly the same as 'name'.
+ * (1) the pathspec string is leading directory of 'name' ("RECURSIVELY"), or
+ * (2) the pathspec string has a leading part matching 'name' ("LEADING"), or
+ * (3) the pathspec string is a wildcard and matches 'name' ("WILDCARD"), or
+ * (4) the pathspec string is exactly the same as 'name' ("EXACT").
*
- * and the return value tells which case it was.
+ * Return value tells which case it was (1-4), or 0 when there is no match.
*
- * It returns 0 when there is no match.
+ * It may be instructive to look at a small table of concrete examples
+ * to understand the differences between 1, 2, and 4:
+ *
+ * Pathspecs
+ * | a/b | a/b/ | a/b/c
+ * ------+-----------+-----------+------------
+ * a/b | EXACT | EXACT[1] | LEADING[2]
+ * Names a/b/ | RECURSIVE | EXACT | LEADING[2]
+ * a/b/c | RECURSIVE | RECURSIVE | EXACT
+ *
+ * [1] Only if DO_MATCH_DIRECTORY is passed; otherwise, this is NOT a match.
+ * [2] Only if DO_MATCH_LEADING_PATHSPEC is passed; otherwise, not a match.
*/
static int match_pathspec_item(const struct index_state *istate,
const struct pathspec_item *item, int prefix,
@@ -353,7 +364,7 @@ static int match_pathspec_item(const struct index_state *istate,
item->nowildcard_len - prefix))
return MATCHED_FNMATCH;
- /* Perform checks to see if "name" is a super set of the pathspec */
+ /* Perform checks to see if "name" is a leading string of the pathspec */
if (flags & DO_MATCH_LEADING_PATHSPEC) {
/* name is a literal prefix of the pathspec */
int offset = name[namelen-1] == '/' ? 1 : 0;
--
2.22.1.11.g45a39ee867
