Null pointer dereference in mrb_class

PoC === The following demonstrates a crash: if def class A ensure e rescue 0 end end [].map.a Debug info ========== The crash happens due to a null pointer dereference in `mrb_class`, class.h:50. 50├> return mrb_obj_ptr(v)->c; Valgrind shows several reads inside free'd blocks. Test platform ============= * Linux Mint 17.3 (Cinnamon 64-bit), built with gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.3 mruby SHA: 051e40c0493f2de332f5439e3230c9fe6958bf1a Thank you, Dinko Galetic Denis Kasak