gui: rapidxml: Bail out if detecting ABX header

The parser is supposed to parse plain XMLs, ABX format is not yet supported.
Continuing to parse ABX XMLs would be spamming /tmp/recovery.log until triggering OOM.

Change-Id: I5c01045d6efef0b2ac497b40d78410c2b75d30d0
(cherry picked from commit 0a352091b39cb62f919af0fbed1097194d3188bf)

gui/rapidxml.hpp

@@ -1390,7 +1390,15 @@ namespace rapidxml
             
             // Parse BOM, if any
             parse_bom<Flags>(text);
-            
+
+            // Abort if it's ABX format
+            if (text[0] == Ch('A') &&
+                text[1] == Ch('B') &&
+                text[2] == Ch('X')) {
+                RAPIDXML_PARSE_ERROR("ABX Format Unsupported by RapidXML", text);
+                return;
+            }
+
             // Parse children
             while (1)
             {