Keep the query string across the about redirects

The hop to the trailing-slash form of the about page, and the hop back
to the summary of a repository without a readme, were built from the
path alone, so a request for the about page of another branch landed
on the default one. The query goes into the Location line as the
client sent it, with any byte a header cannot carry percent-encoded.

1 file changed, 9 insertions, 4 deletions

diff --git a/source/cmd.c b/source/cmd.c
index 38fe596..49c1eb4 100644
--- a/source/cmd.c
+++ b/source/cmd.c
@@ -34,7 +34,7 @@ static void head_fn(void)
 
 static void about_fn(void)
 {
-	char *currenturl, *redirect;
+	char *currenturl, *query, *redirect;
 	size_t path_info_len;
 
 	if (!ctx.repo) {
@@ -43,23 +43,28 @@ static void about_fn(void)
 	}
 
 	// The about page resolves relative links against its own URL, so it
-	// only works with a trailing slash.
+	// only works with a trailing slash. The branch and the rest of the
+	// query travel along with either redirect.
 	path_info_len = ctx.env.path_info ? strlen(ctx.env.path_info) : 0;
 	if (!ctx.qry.path &&
 		(!ctx.qry.url || !*ctx.qry.url || ctx.qry.url[strlen(ctx.qry.url) - 1] != '/') &&
 		(!path_info_len || ctx.env.path_info[path_info_len - 1] != '/')) {
 		currenturl = cgit_currenturl();
+		query = cgit_currentquery();
 		redirect = cgit_fmtalloc("%s/", currenturl);
-		cgit_redirect(redirect, true);
+		cgit_redirect(redirect, query, true);
 		free(currenturl);
+		free(query);
 		free(redirect);
 	} else if (ctx.repo->readme.nr) {
 		cgit_print_repo_readme(ctx.qry.path);
 	} else {
 		currenturl = cgit_currenturl();
+		query = cgit_currentquery();
 		redirect = cgit_fmtalloc("%s../", currenturl);
-		cgit_redirect(redirect, false);
+		cgit_redirect(redirect, query, false);
 		free(currenturl);
+		free(query);
 		free(redirect);
 	}
 }