[libcxx-commits] [libcxx] [regex] fix uncaught exception when string is like "\\_" (PR #129348)

[Mark de Wever via libcxx-commits]

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@@ -3954,7 +3954,7 @@ _ForwardIterator basic_regex<_CharT, _Traits>::__parse_character_escape(
       ++__first;
       break;
     default:
-      if (*__first != '_' && !__traits_.isctype(*__first, ctype_base::alnum)) {
+      if (!__traits_.isctype(*__first, ctype_base::alnum)) {
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mordante wrote:

Can you explain why this is correct and no other changes are required?

Please add this information to the pull request too.

https://github.com/llvm/llvm-project/pull/129348