Merge pull request #3087 from kou/fix-segv-on-rerasing-no-memory-error

Fix SEGV on re-raising NoMemoryError

src/gc.c

@@ -215,6 +215,7 @@ mrb_realloc(mrb_state *mrb, void *p, size_t len)
   p2 = mrb_realloc_simple(mrb, p, len);
   if (!p2 && len) {
     if (mrb->gc.out_of_memory) {
+      mrb_exc_raise(mrb, mrb_obj_value(mrb->nomem_err));
       /* mrb_panic(mrb); */
     }
     else {

src/vm.c

@@ -256,12 +256,13 @@ static void
 cipop(mrb_state *mrb)
 {
   struct mrb_context *c = mrb->c;
-
-  if (c->ci->env) {
-    mrb_env_unshare(mrb, c->ci->env);
-  }
+  struct REnv *env = c->ci->env;
 
   c->ci--;
+
+  if (env) {
+    mrb_env_unshare(mrb, env);
+  }
 }
 
 void mrb_exc_set(mrb_state *mrb, mrb_value exc);