Trim a snapshot name without reading out of bounds

For a url of .git, or an empty one, repo_basename stepped its index to
the byte before its buffer, read it, and would have cleared it had it
held a slash. Git's strbuf trims take the same steps safely, and they
lift the 1024-byte cap that failed the page for a longer url.

2 files changed, 12 insertions, 29 deletions

diff --git a/source/ui-shared.c b/source/ui-shared.cindex 936a6a4..9ad398f 100644--- a/source/ui-shared.c+++ b/source/ui-shared.c@@ -35,33 +35,6 @@ // into a tab title while it still leaves room to spare in that buffer. #define MAX_TITLE_PATH_LEN 256 -static const char *repo_basename(const char *reponame)-{-	// The result lives in a static buffer, so it is only good until the-	// next call.-	static char buf[1024];-	const char *slash;-	size_t len;-	int last;--	len = strlcpy(buf, reponame, sizeof(buf));-	if (len >= sizeof(buf))-		die("Repository name too long: %s", reponame);-	last = len - 1;-	while (last && buf[last] == '/')-		buf[last--] = '\0';-	if (last >= 3 && starts_with(&buf[last - 3], ".git")) {-		last -= 3;-		buf[last--] = '\0';-	}-	while (last && buf[last] == '/')-		buf[last--] = '\0';-	slash = strrchr(buf, '/');-	if (slash)-		return ++slash;-	return buf;-}- static const char *root_url(void) { 	if (ctx.cfg.virtual_root)@@ -955,10 +928,19 @@ void cgit_tree_url(const char *head, struct strbuf *base, struct strbuf *query)  const char *cgit_snapshot_prefix(const struct cgit_repo *repo) {+	static struct strbuf name = STRBUF_INIT;+	const char *slash;+ 	if (repo->snapshot_prefix) 		return repo->snapshot_prefix; -	return repo_basename(repo->url);+	strbuf_reset(&name);+	strbuf_addstr(&name, repo->url);+	strbuf_trim_trailing_dir_sep(&name);+	strbuf_strip_suffix(&name, ".git");+	strbuf_trim_trailing_dir_sep(&name);+	slash = strrchr(name.buf, '/');+	return slash ? slash + 1 : name.buf; }  void cgit_index_link(const char *name, const char *title, const char *class,
diff --git a/source/ui-shared.c b/source/ui-shared.c
index 936a6a4..9ad398f 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -35,33 +35,6 @@
 // into a tab title while it still leaves room to spare in that buffer.
 #define MAX_TITLE_PATH_LEN 256
 
-static const char *repo_basename(const char *reponame)
-{
-	// The result lives in a static buffer, so it is only good until the
-	// next call.
-	static char buf[1024];
-	const char *slash;
-	size_t len;
-	int last;
-
-	len = strlcpy(buf, reponame, sizeof(buf));
-	if (len >= sizeof(buf))
-		die("Repository name too long: %s", reponame);
-	last = len - 1;
-	while (last && buf[last] == '/')
-		buf[last--] = '\0';
-	if (last >= 3 && starts_with(&buf[last - 3], ".git")) {
-		last -= 3;
-		buf[last--] = '\0';
-	}
-	while (last && buf[last] == '/')
-		buf[last--] = '\0';
-	slash = strrchr(buf, '/');
-	if (slash)
-		return ++slash;
-	return buf;
-}
-
 static const char *root_url(void)
 {
 	if (ctx.cfg.virtual_root)
@@ -955,10 +928,19 @@ void cgit_tree_url(const char *head, struct strbuf *base, struct strbuf *query)
 
 const char *cgit_snapshot_prefix(const struct cgit_repo *repo)
 {
+	static struct strbuf name = STRBUF_INIT;
+	const char *slash;
+
 	if (repo->snapshot_prefix)
 		return repo->snapshot_prefix;
 
-	return repo_basename(repo->url);
+	strbuf_reset(&name);
+	strbuf_addstr(&name, repo->url);
+	strbuf_trim_trailing_dir_sep(&name);
+	strbuf_strip_suffix(&name, ".git");
+	strbuf_trim_trailing_dir_sep(&name);
+	slash = strrchr(name.buf, '/');
+	return slash ? slash + 1 : name.buf;
 }
 
 void cgit_index_link(const char *name, const char *title, const char *class,
diff --git a/source/ui-shared.h b/source/ui-shared.hindex da1b889..9abd4c0 100644--- a/source/ui-shared.h+++ b/source/ui-shared.h@@ -125,7 +125,8 @@ extern void cgit_print_snapshot_links(const struct cgit_repo *repo, const char *  /*  * The name a snapshot of this repository is downloaded under, which is the- * configured prefix or the last component of the repository URL.+ * configured prefix or the last component of the repository URL. A name taken+ * from the URL is only good until the next call.  */ extern const char *cgit_snapshot_prefix(const struct cgit_repo *repo); 
diff --git a/source/ui-shared.h b/source/ui-shared.h
index da1b889..9abd4c0 100644
--- a/source/ui-shared.h
+++ b/source/ui-shared.h
@@ -125,7 +125,8 @@ extern void cgit_print_snapshot_links(const struct cgit_repo *repo, const char *
 
 /*
  * The name a snapshot of this repository is downloaded under, which is the
- * configured prefix or the last component of the repository URL.
+ * configured prefix or the last component of the repository URL. A name taken
+ * from the URL is only good until the next call.
  */
 extern const char *cgit_snapshot_prefix(const struct cgit_repo *repo);