From: Jonathan Wakely <jwakely@redhat.com>
Date: Wed, 4 Jan 2023 20:49:59 +0000 (+0000)
Subject: libstdc++: Support single components in name of chrono::current_zone() [PR108211]
X-Git-Tag: basepoints/gcc-14~2203
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=56be1970765b6302de19977790a537d6feaaa34b;p=thirdparty%2Fgcc.git

libstdc++: Support single components in name of chrono::current_zone() [PR108211]

We currently only handle the case where /etc/localtime is a symlink to a
path like ".../Etc/UTC" and fail for ".../UTC". This makes both work.

libstdc++-v3/ChangeLog:

	PR libstdc++/108211
	* src/c++20/tzdb.cc (chrono::current_zone()): Check for zone
	using only last component of the name.
---

diff --git a/libstdc++-v3/src/c++20/tzdb.cc b/libstdc++-v3/src/c++20/tzdb.cc
index 6772517d55ae..9103b1594009 100644
--- a/libstdc++-v3/src/c++20/tzdb.cc
+++ b/libstdc++-v3/src/c++20/tzdb.cc
@@ -1501,8 +1501,11 @@ namespace std::chrono
 	if (std::distance(first, last) > 2)
 	  {
 	    --last;
-	    string name = std::prev(last)->string() + '/';
-	    name += last->string();
+	    string name = last->string();
+	    if (auto tz = do_locate_zone(this->zones, this->links, name))
+	      return tz;
+	    --last;
+	    name = last->string() + '/' + name;
 	    if (auto tz = do_locate_zone(this->zones, this->links, name))
 	      return tz;
 	  }