string.c: clear env self in symbol proc

* string.c (sym_to_proc), proc.c (rb_block_clear_env_self): clear
  caller's self which is useless, so that it can get collected.
  [Fixes GH-592]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45576 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 0 deletions

diff --git a/proc.c b/proc.c
index b36c7aa865..1271a3ba42 100644
--- a/proc.c
+++ b/proc.c
@@ -710,6 +710,17 @@ rb_block_lambda(void)
 }
 
 VALUE
+rb_block_clear_env_self(VALUE proc)
+{
+    rb_proc_t *po;
+    rb_env_t *env;
+    GetProcPtr(proc, po);
+    GetEnvPtr(po->envval, env);
+    env->env[0] = Qnil;
+    return proc;
+}
+
+VALUE
 rb_f_lambda(void)
 {
     rb_warn("rb_f_lambda() is deprecated; use rb_block_proc() instead");