Fix FS#11829 - %?xx<....> Crashes on targets where the %xx feature tag isnt avilable. rather hacky fix though better than crashing.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28890 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 45 insertions, 27 deletions

diff --git a/lib/skin_parser/skin_parser.c b/lib/skin_parser/skin_parser.c
index 80f5f61699..e9f0bf8b47 100644
--- a/lib/skin_parser/skin_parser.c
+++ b/lib/skin_parser/skin_parser.c
@@ -969,37 +969,55 @@ static int skin_parse_conditional(struct skin_element* element, const char** doc
     cursor = bookmark;
 #endif
     /* Parsing the children */
-    element->children = skin_alloc_children(children);
-    if (!element->children)
-        return 0;
-    element->children_count = children;
-
-    for(i = 0; i < children; i++)
+    
+    /* Feature tags could end up having 0 children which breaks
+     * the render in dangerous ways. Minor hack, but insert an empty
+     * child.  (e.g %?xx<foo> when xx isnt available ) */
+    
+    if (children == 0)
     {
-        element->children[i] = skin_parse_code_as_arg(&cursor);
-        if (element->children[i] == NULL)
-            return 0;
-        skip_whitespace(&cursor);
+                const char* emptyline= "";
+                children = 1;
+                element->children = skin_alloc_children(children);
+                if (!element->children)
+                        return 0;
+                element->children_count = children;
+                element->children[0] = skin_parse_code_as_arg(&emptyline);
+        }
+        else
+        {       
+                element->children = skin_alloc_children(children);
+                if (!element->children)
+                        return 0;
+                element->children_count = children;
+
+                for(i = 0; i < children; i++)
+                {
+                        element->children[i] = skin_parse_code_as_arg(&cursor);
+                        if (element->children[i] == NULL)
+                                return 0;
+                        skip_whitespace(&cursor);
 #ifdef ROCKBOX
-        if ((element->tag->flags&FEATURE_TAG) && feature_available)
-            cursor = conditional_end;
+                        if ((element->tag->flags&FEATURE_TAG) && feature_available)
+                                cursor = conditional_end;
 #endif
 
-        if(i < children - 1 && *cursor != ENUMLISTSEPARATESYM)
-        {
-            skin_error(SEPARATOR_EXPECTED, cursor);
-            return 0;
-        }
-        else if(i == children - 1 && *cursor != ENUMLISTCLOSESYM)
-        {
-            skin_error(CLOSE_EXPECTED, cursor);
-            return 0;
-        }
-        else
-        {
-            cursor++;
-        }
-    }
+                        if(i < children - 1 && *cursor != ENUMLISTSEPARATESYM)
+                        {
+                                skin_error(SEPARATOR_EXPECTED, cursor);
+                                return 0;
+                        }
+                        else if(i == children - 1 && *cursor != ENUMLISTCLOSESYM)
+                        {
+                                skin_error(CLOSE_EXPECTED, cursor);
+                                return 0;
+                        }
+                        else
+                        {
+                                cursor++;
+                        }
+                }
+        }
     *document = cursor;
 
     return 1;