From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 26 Apr 2024 10:42:26 +0000 (+0100)
Subject: libstdc++: Do not apply localized formatting to NaN and inf [PR114863]
X-Git-Tag: basepoints/gcc-16~9548
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a0bc71e480132a528a4869c1cd7863f709768c53;p=thirdparty%2Fgcc.git

libstdc++: Do not apply localized formatting to NaN and inf [PR114863]

We don't want to add grouping to strings like "-inf", and there is no
radix character to replace either.

libstdc++-v3/ChangeLog:

	PR libstdc++/114863
	* include/std/format (__formatter_fp::format): Only use
	_M_localized for finite values.
	* testsuite/std/format/functions/format.cc: Check localized
	formatting of NaN and initiny.
---

diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format
index 22dcb5f24bd7..48deba2bcb2d 100644
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -1734,7 +1734,7 @@ namespace __format
 	    }
 #endif
 
-	  if (_M_spec._M_localized)
+	  if (_M_spec._M_localized && __builtin_isfinite(__v))
 	    {
 	      __wstr = _M_localize(__str, __expc, __fc.locale());
 	      if (!__wstr.empty())
diff --git a/libstdc++-v3/testsuite/std/format/functions/format.cc b/libstdc++-v3/testsuite/std/format/functions/format.cc
index 4499397aaf97..78cc1ab482ad 100644
--- a/libstdc++-v3/testsuite/std/format/functions/format.cc
+++ b/libstdc++-v3/testsuite/std/format/functions/format.cc
@@ -248,6 +248,14 @@ test_locale()
   s = std::format(cloc, "{:05L}", -1.0); // PR libstdc++/110968
   VERIFY( s == "-0001" );
 
+  // PR libstdc++/114863 grouping applied to nan and inf
+  double inf = std::numeric_limits<double>::infinity();
+  s = std::format(eloc, "{0:Le} {0:Lf} {0:Lg}", -inf);
+  VERIFY( s == "-inf -inf -inf" );
+  double nan = std::numeric_limits<double>::quiet_NaN();
+  s = std::format(eloc, "{0:Le} {0:Lf} {0:Lg}", -nan);
+  VERIFY( s == "-nan -nan -nan" );
+
   // Restore
   std::locale::global(cloc);
 }