--- ./promenade.c~	2010-08-10 00:14:16.000000000 +0900
+++ ./promenade.c	2010-08-17 17:39:24.000000000 +0900
@@ -413,9 +413,9 @@
     p_userlang = lang;
   }
   if(*p_format == '\0'){
-    if(!strcmp(g_mimerule, "xhtml")) {
+    if(g_mimerule && !strcmp(g_mimerule, "xhtml")) {
       p_format = "xhtml";
-    } else if(!strcmp(g_mimerule, "html")) {
+    } else if(g_mimerule && !strcmp(g_mimerule, "html")) {
       p_format = "html";
     } else {
       rp = getenv("HTTP_ACCEPT");