Fix Bug 19678 - libc++ does not correctly handle the regex: '[^\0]*'

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@209307 91177308-0d34-0410-b5e6-96231b3b80d8

include/regex

@@ -4541,6 +4541,13 @@ basic_regex<_CharT, _Traits>::__parse_character_escape(_ForwardIterator __first,
                 __push_char(_CharT(__sum));
             ++__first;
             break;
+        case '0':
+            if (__str)
+                *__str = _CharT(0);
+            else
+                __push_char(_CharT(0));
+            ++__first;
+            break;
         default:
             if (*__first != '_' && !__traits_.isctype(*__first, ctype_base::alnum))
             {

test/re/re.alg/re.alg.match/ecma.pass.cpp

@@ -608,6 +608,18 @@ int main()
         assert(m.position(0) == 0);
         assert(m.str(0) == s);
     }
+    {
+        std::cmatch m;
+        const char s[] = "foobar";
+        assert(std::regex_match(s, m, std::regex("[^\\0]*")));
+        assert(m.size() == 1);
+    }
+    {
+        std::cmatch m;
+        const char s[] = "foo\0bar";
+        assert(std::regex_match(s, s+7, m, std::regex("[abfor\\0]*")));
+        assert(m.size() == 1);
+    }
     std::locale::global(std::locale("C"));
     {
         std::cmatch m;