string.c: search by rb_str_index

* re.c (match_regexp): set regexp for MatchData from string.
* re.c (rb_backref_set_string): create MatchData from string and
  set backref.
* string.c (rb_pat_search, rb_str_sub, rb_str_sub_bang, str_gsub),
  (scan_once, rb_str_scan, rb_str_partition): use rb_str_index
  instead of rb_reg_search() when pattern is a String.  based on
  the patch by Sam Rawlins <sam.rawlins@gmail.com> [Fixes GH-579]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45451 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 8 insertions, 0 deletions

diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index 6cf45fd537..5c8c4184a0 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -831,6 +831,8 @@ class TestString < Test::Unit::TestCase
     c.force_encoding Encoding::US_ASCII
 
     assert_equal Encoding::UTF_8, a.gsub(/world/, c).encoding
+
+    assert_equal S("a\u{e9}apos&lt;"), S("a\u{e9}'&lt;").gsub("'", "apos")
   end
 
   def test_gsub!
@@ -1454,6 +1456,12 @@ class TestString < Test::Unit::TestCase
     o = Object.new
     def o.to_s; self; end
     assert_match(/^foo#<Object:0x.*>baz$/, "foobarbaz".sub("bar") { o })
+
+    assert_equal(S("Abc"), S("abc").sub("a", "A"))
+    m = nil
+    assert_equal(S("Abc"), S("abc").sub("a") {m = $~; "A"})
+    assert_equal(S("a"), m[0])
+    assert_equal(/a/, m.regexp)
   end
 
   def test_sub!