From 3bc8ffe276d13346b51a2d07ebcbeffefdd7bf1a Mon Sep 17 00:00:00 2001
From: Edward Thomson <ethomson@edwardthomson.com>
Date: Tue, 26 May 2026 20:53:50 +0100
Subject: [PATCH] regexp: update pcre2 for type safety

---
 src/util/regexp.c | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/src/util/regexp.c b/src/util/regexp.c
index 84d5b607c..ca0d043ec 100644
--- a/src/util/regexp.c
+++ b/src/util/regexp.c
@@ -84,8 +84,9 @@ int git_regexp_compile(git_regexp *r, const char *pattern, int flags)
 	if (flags & GIT_REGEXP_ICASE)
 		cflags |= PCRE2_CASELESS;
 
-	if ((*r = pcre2_compile((const unsigned char *) pattern, PCRE2_ZERO_TERMINATED,
-				cflags, &error, &erroff, NULL)) == NULL) {
+	if ((*r = pcre2_compile((const unsigned char *) pattern,
+			PCRE2_ZERO_TERMINATED,
+			cflags, &error, &erroff, NULL)) == NULL) {
 		pcre2_get_error_message(error, errmsg, sizeof(errmsg));
 		git_error_set_str(GIT_ERROR_REGEX, (char *) errmsg);
 		return GIT_EINVALIDSPEC;
@@ -110,37 +111,51 @@ int git_regexp_match(const git_regexp *r, const char *string)
 
 	error = pcre2_match(*r, (const unsigned char *) string, strlen(string), 0, 0, data, NULL);
 	pcre2_match_data_free(data);
+
 	if (error < 0)
 		return (error == PCRE2_ERROR_NOMATCH) ? GIT_ENOTFOUND : GIT_EINVALIDSPEC;
 
 	return 0;
 }
 
-int git_regexp_search(const git_regexp *r, const char *string, size_t nmatches, git_regmatch *matches)
+int git_regexp_search(
+	const git_regexp *r,
+	const char *string,
+	size_t given_nmatches,
+	git_regmatch *matches)
 {
 	pcre2_match_data *data = NULL;
 	PCRE2_SIZE *ovec;
+	size_t i, captures;
+	uint32_t nmatches;
 	int error;
-	size_t i;
+
+	GIT_ASSERT(given_nmatches <= UINT32_MAX);
+
+	nmatches = (uint32_t) given_nmatches;
 
 	if ((data = pcre2_match_data_create(nmatches, NULL)) == NULL) {
 		git_error_set_oom();
 		return -1;
 	}
 
-	if ((error = pcre2_match(*r, (const unsigned char *) string, strlen(string),
-			     0, 0, data, NULL)) < 0)
+	if ((error = pcre2_match(*r, (const unsigned char *) string,
+			strlen(string), 0, 0, data, NULL)) < 0)
 		goto out;
 
-	if (error == 0 || (unsigned int) error  > nmatches)
-		error = nmatches;
+	captures = (size_t) error;
+
+	if (!captures || captures > nmatches)
+		captures = nmatches;
+
 	ovec = pcre2_get_ovector_pointer(data);
 
-	for (i = 0; i < (unsigned int) error; i++) {
+	for (i = 0; i < captures; i++) {
 		matches[i].start = (ovec[i * 2] == PCRE2_UNSET) ? -1 : (ssize_t) ovec[i * 2];
 		matches[i].end = (ovec[i * 2 + 1] == PCRE2_UNSET) ? -1 :  (ssize_t) ovec[i * 2 + 1];
 	}
-	for (i = (unsigned int) error; i < nmatches; i++)
+
+	for (i = captures; i < nmatches; i++)
 		matches[i].start = matches[i].end = -1;
 
 out: