[gcc r11-9921] libstdc++: Fix filesystem::temp_directory_path [PR101709]

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:df783ecbaaea340297df8a3bd6666068ce131a33

commit r11-9921-gdf783ecbaaea340297df8a3bd6666068ce131a33
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Aug 2 15:52:41 2021 +0100

    libstdc++: Fix filesystem::temp_directory_path [PR101709]
    
    Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/101709
            * src/filesystem/ops-common.h (get_temp_directory_from_env):
            Add error_code parameter.
            * src/c++17/fs_ops.cc (fs::temp_directory_path): Pass error_code
            argument to get_temp_directory_from_env and check it.
            * src/filesystem/ops.cc (fs::temp_directory_path): Likewise.
    
    (cherry picked from commit 38fb24ba4d67254cea78731fc8d961903dad9646)

Diff:
---
 libstdc++-v3/src/c++17/fs_ops.cc         |  4 +++-
 libstdc++-v3/src/filesystem/ops-common.h | 13 +++++++------
 libstdc++-v3/src/filesystem/ops.cc       |  4 +++-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
index 3d437cd0634..2eac9977785 100644
--- a/libstdc++-v3/src/c++17/fs_ops.cc
+++ b/libstdc++-v3/src/c++17/fs_ops.cc
@@ -1597,7 +1597,9 @@ fs::temp_directory_path()
 fs::path
 fs::temp_directory_path(error_code& ec)
 {
-  path p = fs::get_temp_directory_from_env();
+  path p = fs::get_temp_directory_from_env(ec);
+  if (ec)
+    return p;
   auto st = status(p, ec);
   if (ec)
     p.clear();
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index 714514bc116..a76a2e6198d 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -571,7 +571,7 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
   // Caller must check that the path is an accessible directory.
 #ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
   inline wstring
-  get_temp_directory_from_env()
+  get_temp_directory_from_env(error_code& ec)
   {
     unsigned len = 1024;
     std::wstring buf;
@@ -582,17 +582,18 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
       } while (len > buf.size());
 
     if (len == 0)
-      {
-	ec.assign((int)GetLastError(), std::system_category());
-	return p;
-      }
+      ec.assign((int)GetLastError(), std::system_category());
+    else
+      ec.clear();
+
     buf.resize(len);
     return buf;
   }
 #else
   inline const char*
-  get_temp_directory_from_env() noexcept
+  get_temp_directory_from_env(error_code& ec) noexcept
   {
+    ec.clear();
     for (auto env : { "TMPDIR", "TMP", "TEMP", "TEMPDIR" })
       {
 #if _GLIBCXX_HAVE_SECURE_GETENV
diff --git a/libstdc++-v3/src/filesystem/ops.cc b/libstdc++-v3/src/filesystem/ops.cc
index f4ebf789078..1ee22967a4f 100644
--- a/libstdc++-v3/src/filesystem/ops.cc
+++ b/libstdc++-v3/src/filesystem/ops.cc
@@ -1302,7 +1302,9 @@ fs::temp_directory_path()
 fs::path
 fs::temp_directory_path(error_code& ec)
 {
-  path p = fs::get_temp_directory_from_env();
+  path p = fs::get_temp_directory_from_env(ec);
+  if (ec)
+    return p;
   auto st = status(p, ec);
   if (ec)
     p.clear();