Throw the proper exception on a regex range error

[Mordante]

Summary

While looking at bug 39575 I noticed the wrong exception was thrown. This fixes the exception thrown and adds a unit test.

[mclow.lists]

LGTM - thanks!
Do you need me to commit this?

[Mordante]

Thanks for the review.
Yes, please commit it for me since I don't have commit access.

[mclow.lists]

Landed as revision 361887.

libcxx/include/regex

void __add_range(string_type __b, string_type __e)
                 }
                 __ranges_.push_back(make_pair(
                                   __traits_.transform(__b.begin(), __b.end()),
                                   __traits_.transform(__e.begin(), __e.end())));
             }
             else
             {
                 if (__b.size() != 1 || __e.size() != 1)
-                    __throw_regex_error<regex_constants::error_collate>();
+                    __throw_regex_error<regex_constants::error_range>();
                 if (__icase_)
                 {
                     __b[0] = __traits_.translate_nocase(__b[0]);
                     __e[0] = __traits_.translate_nocase(__e[0]);
                 }
                 __ranges_.push_back(make_pair(_VSTD::move(__b), _VSTD::move(__e)));
             }
         }

libcxx/test/std/re/re.regex/re.regex.construct/bad_range.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: libcpp-no-exceptions
+// <regex>
+
+// template <class charT, class traits = regex_traits<charT>> class basic_regex;
+
+// template <class ST, class SA>
+//    basic_regex(const basic_string<charT, ST, SA>& s);
+
+#include <regex>
+#include <cassert>
+#include "test_macros.h"
+
+static bool error_range_thrown(const char *pat)
+{
+    bool result = false;
+    try {
+        std::regex re(pat);
+    } catch (const std::regex_error &ex) {
+        result = (ex.code() == std::regex_constants::error_range);
+    }
+    return result;
+}
+
+int main(int, char**)
+{
+    assert(error_range_thrown(R"([\w-a])"));
+    assert(error_range_thrown(R"([a-\w])"));
+
+  return 0;
+}