[Patch, libstdc++/64649] Fix regex_traits::lookup_collatename and regex_traits::lookup_classname

[Tim Shen]

On Mon, Jan 19, 2015 at 3:52 PM, Tim Shen <timshen@google.com> wrote:
> I think it'll be a quick fix.

Here it is :)


-- 
Regards,
Tim Shen
-------------- next part --------------
commit a2058d87f3b9e2f00a11ae55c2598d00829022cd
Author: timshen <timshen@google.com>
Date:   Mon Jan 19 16:21:10 2015 -0800

    	PR libstdc++/64649
    	* include/bits/regex.tcc (regex_traits<>::lookup_collatename,
    	regex_traits<>::lookup_classname): Correctly narrow input chars.
    	* testsuite/28_regex/traits/wchar_t/user_defined.cc: New testcase.

diff --git a/libstdc++-v3/include/bits/regex.tcc b/libstdc++-v3/include/bits/regex.tcc
index 3f16e66..aad56e0 100644
--- a/libstdc++-v3/include/bits/regex.tcc
+++ b/libstdc++-v3/include/bits/regex.tcc
@@ -269,7 +269,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  "DEL",
 	};
 
-      string __s(__first, __last);
+      string __s;
+      for (; __first != __last; ++__first)
+	__s += __fctyp.narrow(*__first, 0);
+
       for (const auto& __it : __collatenames)
 	if (__s == __it)
 	  return string_type(1, __fctyp.widen(
@@ -311,8 +314,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       };
 
       string __s;
-      for (auto __cur = __first; __cur != __last; ++__cur)
-	__s += __fctyp.narrow(__fctyp.tolower(*__cur), '?');
+      for (; __first != __last; ++__first)
+	__s += __fctyp.narrow(__fctyp.tolower(*__first), 0);
 
       for (const auto& __it : __classnames)
 	if (__s == __it.first)
diff --git a/libstdc++-v3/testsuite/28_regex/traits/wchar_t/user_defined.cc b/libstdc++-v3/testsuite/28_regex/traits/wchar_t/user_defined.cc
index 16bcd6a..0f55f74 100644
--- a/libstdc++-v3/testsuite/28_regex/traits/wchar_t/user_defined.cc
+++ b/libstdc++-v3/testsuite/28_regex/traits/wchar_t/user_defined.cc
@@ -55,8 +55,32 @@ test01()
   VERIFY(!regex_match(L"\u2029", re));
 }
 
+struct MyCtype : std::ctype<wchar_t>
+{
+  char
+  do_narrow(wchar_t c, char dflt) const override
+  {
+    if (c >= 256)
+      return dflt;
+    return ((char)c)+1;
+  }
+};
+
+void
+test02()
+{
+  std::locale loc(std::locale(), new MyCtype);
+  std::regex_traits<wchar_t> traits;
+  traits.imbue(loc);
+  wchar_t wch = L'p';
+  VERIFY(traits.lookup_collatename(&wch, &wch+1) == L"q");
+  std::wstring ws = L"`kog`"; // chars of "alpha" shifted by 1.
+  VERIFY(traits.lookup_classname(ws.begin(), ws.end()) != 0);
+}
+
 int main()
 {
   test01();
+  test02();
   return 0;
 }