merges r20603 from trunk into ruby_1_9_1.

* re.c (rb_reg_initialize): raise RegexpError when encoding
  is dummy encoding. [ruby-dev:37091]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@20690 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 0 deletions

diff --git a/re.c b/re.c
index 3a2aa5d36..a45ae47d9 100644
--- a/re.c
+++ b/re.c
@@ -2312,6 +2312,11 @@ rb_reg_initialize(VALUE obj, const char *s, int len, rb_encoding *enc,
         rb_raise(rb_eTypeError, "already initialized regexp");
     re->ptr = 0;
 
+    if (rb_enc_dummy_p(enc)) {
+	    strcpy(err, "can't make regexp with dummy encoding");
+	    return -1;
+    }
+
     unescaped = rb_reg_preprocess(s, s+len, enc, &fixed_enc, err);
     if (unescaped == Qnil)
         return -1;