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, 15 insertions, 6 deletions

diff --git a/source/ui-shared.c b/source/ui-shared.c
index 0f2f1e3..147472e 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -828,16 +828,15 @@ char *cgit_currenturl(void)
 	return cgit_fmtalloc("%s/%s", root, ctx.qry.url);
 }
 
-char *cgit_currentfullurl(void)
+char *cgit_currentquery(void)
 {
-	const char *root = root_url();
 	const char *orig_query = ctx.env.query_string ? ctx.env.query_string : "";
 	size_t len = strlen(orig_query);
 	char *query = xmalloc(len + 2);
-	char *match, *ret;
+	char *match;
 
-	// The url argument carried the path into this request and the path is
-	// spelled out again below, so it is dropped here. The copy keeps a
+	// The url argument carried the path into this request and every caller
+	// spells the path out again, so it is dropped here. The copy keeps a
 	// leading question mark so that every match has a character before it,
 	// which is what tells the argument itself from the tail of another one.
 	memcpy(query + 1, orig_query, len + 1);
@@ -856,6 +855,14 @@ char *cgit_currentfullurl(void)
 	}
 	if (!query[1])
 		query[0] = '\0';
+	return query;
+}
+
+char *cgit_currentfullurl(void)
+{
+	const char *root = root_url();
+	char *query = cgit_currentquery();
+	char *ret;
 
 	if (!ctx.qry.url)
 		ret = cgit_fmtalloc("%s%s", root, query);
@@ -1453,11 +1460,13 @@ void cgit_print_http_headers(void)
 		exit(0);
 }
 
-void cgit_redirect(const char *url, bool permanent)
+void cgit_redirect(const char *url, const char *query, bool permanent)
 {
 	htmlf("Status: %d %s\n", permanent ? 301 : 302, permanent ? "Moved Permanently" : "Found");
 	html("Location: ");
 	html_url_path(url);
+	if (query)
+		html_header_query(query);
 	html("\n\n");
 }