--- modules/http/http_core.c	Wed Sep 19 14:54:51 2018
+++ modules/http/http_core.c	Wed Dec  5 19:56:20 2018
@@ -115,18 +115,22 @@
     /*
      * The http module shouldn't return anything other than
      * "http" (the default) or "https".
+     * Bug 61355 - DirectorySlash directive should use protocol in X-Forwarded-Proto header when available
      */
+    char *scheme;
     if (r->server->server_scheme &&
         (strcmp(r->server->server_scheme, "https") == 0))
         return "https";
+    if ((scheme = apr_table_get(r->headers_in, "X-Forwarded-Proto")) &&
+        (strcmp(scheme, "https") == 0))
+        return "https";
 
     return "http";
 }
 
 static apr_port_t http_port(const request_rec *r)
 {
-    if (r->server->server_scheme &&
-        (strcmp(r->server->server_scheme, "https") == 0))
+    if (strcmp(http_scheme(r), "https") == 0)
         return DEFAULT_HTTPS_PORT;
 
     return DEFAULT_HTTP_PORT;