Fix:Core:Don't crash with empty displaylist

git-svn-id: https://navit.svn.sourceforge.net/svnroot/navit/trunk/navit@2860 ffa7fe5e-494d-0410-b361-a75ebd5db220

diff --git a/navit/graphics.c b/navit/graphics.c
index 044415e..a391994 100644 (file)
--- a/navit/graphics.c
+++ b/navit/graphics.c
@@ -1929,7 +1929,13 @@ struct displaylist_handle * graphics_displaylist_open(struct displaylist *displa
        struct displaylist_handle *ret;
 
        ret=g_new0(struct displaylist_handle, 1);
+       if (!displaylist->dl)
+               return NULL;
        ret->hl_head=ret->hl=g_hash_to_list(displaylist->dl);
+       if (!ret->hl) {
+               g_free(ret);
+               return NULL;
+       }
        ret->l_head=ret->l=g_hash_to_list_keys(ret->hl->data);
 
        return ret;
@@ -1944,6 +1950,8 @@ struct displaylist_handle * graphics_displaylist_open(struct displaylist *displa
 struct displayitem * graphics_displaylist_next(struct displaylist_handle *dlh)
 {
        struct displayitem *ret;
+       if (!dlh)
+               return NULL;
        if (! dlh->l) {
                dlh->hl=g_list_next(dlh->hl);
                if (!dlh->hl)
@@ -1964,9 +1972,11 @@ struct displayitem * graphics_displaylist_next(struct displaylist_handle *dlh)
 */
 void graphics_displaylist_close(struct displaylist_handle *dlh)
 {
-       g_list_free(dlh->hl_head);
-       g_list_free(dlh->l_head);
-       g_free(dlh);
+       if (dlh) {
+               g_list_free(dlh->hl_head);
+               g_list_free(dlh->l_head);
+               g_free(dlh);
+       }
 }
 
 /**