if generateStructInfo gets invalid data, return null, do not throw: possibly duplicate struct names, and it is ok to return null

src/runtime.js

@@ -280,7 +280,10 @@ var Runtime = {
       offset = offset || 0;
       type = (typeof Types === 'undefined' ? Runtime.typeInfo : Types.types)[typeName];
       if (!type) return null;
-      assert(type.fields.length === struct.length, 'Number of named fields must match the type for ' + typeName);
+      if (type.fields.length != struct.length) {
+        printErr('Number of named fields must match the type for ' + typeName + ': possibly duplicate struct names. Cannot return structInfo');
+        return null;
+      }
       alignment = type.flatIndexes;
     } else {
       var type = { fields: struct.map(function(item) { return item[0] }) };

tests/runner.py

@@ -5143,6 +5143,19 @@ int main(int argc, char **argv) {
         }
       '''
       self.do_run(src, 'value:10')
+
+    def test_fakestat(self):
+      src = r'''
+        #include <stdio.h>
+        struct stat { int x, y; };
+        int main() {
+          stat s;
+          s.x = 10;
+          s.y = 22;
+          printf("*%d,%d*\n", s.x, s.y);
+        }
+      '''
+      self.do_run(src, '*10,22*')
       
     def test_mmap(self):
       src = '''