re.c: consider the case of RMatch::regexp is nil

Follow r49675, r57098 and r57110. Don't assume RMatch::regexp always
contains a valid Regexp instance; it will be Qnil if the MatchData is
created by rb_backref_set_string().  [ruby-core:78741] [Bug #13054]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57123 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

re.c

@@ -1089,6 +1089,8 @@ static VALUE
 match_names(VALUE match)
 {
     match_check(match);
+    if (NIL_P(RMATCH(match)->regexp))
+	return rb_ary_new_capa(0);
     return rb_reg_names(RMATCH(match)->regexp);
 }
 
@@ -2078,6 +2080,8 @@ match_named_captures(VALUE match)
     struct MEMO *memo;
 
     match_check(match);
+    if (NIL_P(RMATCH(match)->regexp))
+	return rb_hash_new();
 
     hash = rb_hash_new();
     memo = MEMO_NEW(hash, match, 0);
@@ -2948,7 +2952,7 @@ match_hash(VALUE match)
 
     match_check(match);
     hashval = rb_hash_start(rb_str_hash(RMATCH(match)->str));
-    hashval = rb_hash_uint(hashval, reg_hash(RMATCH(match)->regexp));
+    hashval = rb_hash_uint(hashval, reg_hash(match_regexp(match)));
     regs = RMATCH_REGS(match);
     hashval = rb_hash_uint(hashval, regs->num_regs);
     hashval = rb_hash_uint(hashval, rb_memhash(regs->beg, regs->num_regs * sizeof(*regs->beg)));
@@ -2970,11 +2974,12 @@ static VALUE
 match_equal(VALUE match1, VALUE match2)
 {
     const struct re_registers *regs1, *regs2;
+
     if (match1 == match2) return Qtrue;
     if (!RB_TYPE_P(match2, T_MATCH)) return Qfalse;
     if (!RMATCH(match1)->regexp || !RMATCH(match2)->regexp) return Qfalse;
     if (!rb_str_equal(RMATCH(match1)->str, RMATCH(match2)->str)) return Qfalse;
-    if (!rb_reg_equal(RMATCH(match1)->regexp, RMATCH(match2)->regexp)) return Qfalse;
+    if (!rb_reg_equal(match_regexp(match1), match_regexp(match2))) return Qfalse;
     regs1 = RMATCH_REGS(match1);
     regs2 = RMATCH_REGS(match2);
     if (regs1->num_regs != regs2->num_regs) return Qfalse;

test/ruby/test_regexp.rb

@@ -644,14 +644,30 @@ class TestRegexp < Test::Unit::TestCase
   end
 
   def test_match_without_regexp
+    # create a MatchData for each assertion because the internal state may change
+    test = proc {|&blk| "abc".sub("a", ""); blk.call($~) }
+
     bug10877 = '[ruby-core:68209] [Bug #10877]'
-    "abc".sub("a", "")
-    assert_raise_with_message(IndexError, /foo/, bug10877) {$~["foo"]}
+    test.call {|m| assert_raise_with_message(IndexError, /foo/, bug10877) {m["foo"]} }
     key = "\u{3042}"
     [Encoding::UTF_8, Encoding::Shift_JIS, Encoding::EUC_JP].each do |enc|
       idx = key.encode(enc)
-      assert_raise_with_message(IndexError, /#{idx}/, bug10877) {$~[idx]}
+      test.call {|m| assert_raise_with_message(IndexError, /#{idx}/, bug10877) {m[idx]} }
     end
+    test.call {|m| assert_equal(/a/, m.regexp) }
+    test.call {|m| assert_equal("abc", m.string) }
+    test.call {|m| assert_equal(1, m.size) }
+    test.call {|m| assert_equal(0, m.begin(0)) }
+    test.call {|m| assert_equal(1, m.end(0)) }
+    test.call {|m| assert_equal([0, 1], m.offset(0)) }
+    test.call {|m| assert_equal([], m.captures) }
+    test.call {|m| assert_equal([], m.names) }
+    test.call {|m| assert_equal({}, m.named_captures) }
+    test.call {|m| assert_equal(/a/.match("abc"), m) }
+    test.call {|m| assert_equal(/a/.match("abc").hash, m.hash) }
+    test.call {|m| assert_equal("bc", m.post_match) }
+    test.call {|m| assert_equal("", m.pre_match) }
+    test.call {|m| assert_equal(["a", nil], m.values_at(0, 1)) }
   end
 
   def test_last_match