libstdc++: Use non-throwing increment in recursive_directory_iterator [PR 97731]

As described in the PR, the recursive_directory_iterator constructor
calls advance(ec), but ec is a pointer so it calls _Dir::advance(bool).
The intention was to either call advance() or advance(*ec) depending
whether the pointer is null or not.

This fixes the bug and renames the parameter to ecptr to make similar
mistakes less likely in future.

libstdc++-v3/ChangeLog:

	PR libstdc++/97731
	* src/filesystem/dir.cc (recursive_directory_iterator): Call the
	right overload of _Dir::advance.
	* testsuite/experimental/filesystem/iterators/97731.cc: New test.

1 files changed, 11 insertions, 7 deletions

diff --git a/libstdc++-v3/src/filesystem/dir.cc b/libstdc++-v3/src/filesystem/dir.cc
index 86aee2d..5109897 100644
--- a/libstdc++-v3/src/filesystem/dir.cc
+++ b/libstdc++-v3/src/filesystem/dir.cc
@@ -187,16 +187,16 @@ struct fs::recursive_directory_iterator::_Dir_stack : std::stack<_Dir>
 
 fs::recursive_directory_iterator::
 recursive_directory_iterator(const path& p, directory_options options,
-                             error_code* ec)
+                             error_code* ecptr)
 : _M_options(options), _M_pending(true)
 {
-  if (ec)
-    ec->clear();
   if (posix::DIR* dirp = posix::opendir(p.c_str()))
     {
+      if (ecptr)
+	ecptr->clear();
       auto sp = std::make_shared<_Dir_stack>();
       sp->push(_Dir{ dirp, p });
-      if (sp->top().advance(ec))
+      if (ecptr ? sp->top().advance(*ecptr) : sp->top().advance())
 	_M_dirs.swap(sp);
     }
   else
@@ -204,14 +204,18 @@ recursive_directory_iterator(const path& p, directory_options options,
       const int err = errno;
       if (err == EACCES
 	  && is_set(options, fs::directory_options::skip_permission_denied))
-	return;
+	{
+	  if (ecptr)
+	    ecptr->clear();
+	  return;
+	}
 
-      if (!ec)
+      if (!ecptr)
 	_GLIBCXX_THROW_OR_ABORT(filesystem_error(
 	      "recursive directory iterator cannot open directory", p,
 	      std::error_code(err, std::generic_category())));
 
-      ec->assign(err, std::generic_category());
+      ecptr->assign(err, std::generic_category());
     }
 }