[PATCH 2/4] ref-filter: simplify lstrip_ref_components() memory handling

From: Jeff King <peff@peff.net>
Date: Feb 15, 2026, 09:02 UTC
Message-ID: <20260215090223.GB695631@coredump.intra.peff.net>
In-Reply-To: <20260215085755.GA86262@coredump.intra.peff.net>

We're walking forward in the string, skipping path components from left-to-right. So when we've stripped as much as we want, the pointer we have is a complete NUL-terminated string and we can just return it (after duplicating it, of course). So there is no need for a temporary allocated string.

But we do make an extra temporary copy due to f0062d3b74 (ref-filter: free item->value and item->value->s, 2018-10-18). This is probably from cargo-culting the technique used in rstrip_ref_components(), which _does_ need a separate string (since it is stripping from the end and ties off the temporary string with a NUL).

Let's drop the extra allocation. This is slightly more efficient, but more importantly makes the code much simpler.

Signed-off-by: Jeff King <peff@peff.net>
---
 ref-filter.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index 9153331f42..eb09fda21b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2196,23 +2196,18 @@ static int normalize_component_count(const char *refname, int len)
 static const char *lstrip_ref_components(const char *refname, int len)
 {
 	int remaining = normalize_component_count(refname, len);
-	const char *start = xstrdup(refname);
-	const char *to_free = start;
 
 	while (remaining > 0) {
-		switch (*start++) {
+		switch (*refname++) {
 		case '\0':
-			free((char *)to_free);
 			return xstrdup("");
 		case '/':
 			remaining--;
 			break;
 		}
 	}
 
-	start = xstrdup(start);
-	free((char *)to_free);
-	return start;
+	return xstrdup(refname);
 }
 
 static const char *rstrip_ref_components(const char *refname, int len)

-- 
2.53.0.438.gad17e1cd28