Add macro MRB_ENV_UNSHARE_STACK instead of assigning -1 directly.

3 files changed, 3 insertions, 2 deletions

diff --git a/include/mruby/proc.h b/include/mruby/proc.h
index 6d2cf516a..e72e8f7e4 100644
--- a/include/mruby/proc.h
+++ b/include/mruby/proc.h
@@ -21,6 +21,7 @@ struct REnv {
 };
 
 #define MRB_ENV_STACK_LEN(e) ((e)->flags)
+#define MRB_ENV_UNSHARE_STACK(e) ((e)->cioff = -1)
 
 struct RProc {
   MRB_OBJECT_HEADER;
diff --git a/mrbgems/mruby-proc-ext/src/proc.c b/mrbgems/mruby-proc-ext/src/proc.c
index b4744fa1b..8b6ee4740 100644
--- a/mrbgems/mruby-proc-ext/src/proc.c
+++ b/mrbgems/mruby-proc-ext/src/proc.c
@@ -17,7 +17,7 @@ mrb_proc_new_cfunc_with_env(mrb_state *mrb, mrb_func_t f, mrb_int argc, const mr
   p->env = e;
   mrb_gc_arena_restore(mrb, ai);
 
-  e->cioff = -1;
+  MRB_ENV_UNSHARE_STACK(e);
   MRB_ENV_STACK_LEN(e) = argc;
   e->stack = (mrb_value*)mrb_malloc(mrb, sizeof(mrb_value) * argc);
   for (i = 0; i < argc; ++i) {
diff --git a/src/vm.c b/src/vm.c
index e2b02a4ce..4aa9b9460 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -248,7 +248,7 @@ cipop(mrb_state *mrb)
     size_t len = (size_t)MRB_ENV_STACK_LEN(e);
     mrb_value *p = (mrb_value *)mrb_malloc(mrb, sizeof(mrb_value)*len);
 
-    e->cioff = -1;
+    MRB_ENV_UNSHARE_STACK(e);
     stack_copy(p, e->stack, len);
     e->stack = p;
   }