gistfile1.diff

diff --git a/src/guiFormSpecMenu.cpp b/src/guiFormSpecMenu.cpp
index 920a7f1..82def74 100644
--- a/src/guiFormSpecMenu.cpp
+++ b/src/guiFormSpecMenu.cpp
@@ -421,6 +421,12 @@ void GUIFormSpecMenu::parseList(parserData* data,std::string element) {
                s32 start_i = 0;
                if(startindex != "")
                        start_i = stoi(startindex);
+
+               if (geom.X < 0 || geom.Y < 0 || start_i < 0) {
+                       errorstream<< "Invalid list element: '" << element << "'"  << std::endl;
+                       return;
+               }
+
                if(data->bp_set != 2)
                        errorstream<<"WARNING: invalid use of list without a size[] element"<<std::endl;
                m_inventorylists.push_back(ListDrawSpec(loc, listname, pos, geom, start_i));