dbm.c: yield dup of keystr

* ext/dbm/dbm.c (fdbm_fetch): yield dup of keystr, to make it shared
  and get rid of use of uninitialized variable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44482 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 2 deletions

diff --git a/ext/dbm/dbm.c b/ext/dbm/dbm.c
index 1fdbaa0aca..03616fd4d8 100644
--- a/ext/dbm/dbm.c
+++ b/ext/dbm/dbm.c
@@ -259,8 +259,11 @@ fdbm_fetch(VALUE obj, VALUE keystr, VALUE ifnone)
     value = dbm_fetch(dbm, key);
     if (value.dptr == 0) {
       not_found:
-	if (ifnone == Qnil && rb_block_given_p())
-	    return rb_yield(rb_tainted_str_new(key.dptr, key.dsize));
+	if (NIL_P(ifnone) && rb_block_given_p()) {
+	    keystr = rb_str_dup(keystr);
+	    OBJ_TAINT(keystr);
+	    return rb_yield(keystr);
+	}
 	return ifnone;
     }
     return rb_tainted_str_new(value.dptr, value.dsize);