PR libstdc++/90557 fix path assignment that alters source

Backport from mainline
2019-05-22  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/90557
	* src/c++17/fs_path.cc (path::_List::operator=(const _List&)): Fix
	reversed arguments to uninitialized_copy_n.
	* testsuite/27_io/filesystem/path/assign/copy.cc: Check that source
	is unchanged by copy assignment.
	* testsuite/util/testsuite_fs.h (compare_paths): Use std::equal to
	compare path components.

From-SVN: r271528

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index e36154d14dc2920779f1194e91d06d730e434291..91bd18d9fc8131685527a025ecc2957ce0418d15 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,16 @@
+2019-05-22  Jonathan Wakely  <jwakely@redhat.com>
+
+       Backport from mainline
+       2019-05-22  Jonathan Wakely  <jwakely@redhat.com>
+
+       PR libstdc++/90557
+       * src/c++17/fs_path.cc (path::_List::operator=(const _List&)): Fix
+       reversed arguments to uninitialized_copy_n.
+       * testsuite/27_io/filesystem/path/assign/copy.cc: Check that source
+       is unchanged by copy assignment.
+       * testsuite/util/testsuite_fs.h (compare_paths): Use std::equal to
+       compare path components.
+
 2019-05-20  Jonathan Wakely  <jwakely@redhat.com>
 
        Backported from mainline

diff --git a/libstdc++-v3/src/c++17/fs_path.cc b/libstdc++-v3/src/c++17/fs_path.cc
index 605f62cbf816aa435712228fa0ac65281ecc1ea4..8e01bf510d3edf847c4a22f444211f58e5b76010 100644 (file)
--- a/libstdc++-v3/src/c++17/fs_path.cc
+++ b/libstdc++-v3/src/c++17/fs_path.cc
@@ -278,8 +278,8 @@ path::_List::operator=(const _List& other)
            to[i]._M_pathname.reserve(from[i]._M_pathname.length());
          if (newsize > oldsize)
            {
-             std::uninitialized_copy_n(to + oldsize, newsize - oldsize,
-                                       from + oldsize);
+             std::uninitialized_copy_n(from + oldsize, newsize - oldsize,
+                                       to + oldsize);
              impl->_M_size = newsize;
            }
          else if (newsize < oldsize)

diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc
index 775dbffad36860374291dbdaf34a334e23a975fd..6aa25ae12ef3498c53f537a14c3b6952e4c6b8e9 100644 (file)
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc
@@ -64,10 +64,25 @@ test03()
   VERIFY( ptr2 == p.begin()->c_str() );
 }
 
+void
+test04()
+{
+  // PR libstdc++/90557
+  path p1 = "a/b/c";
+  const path p2 = "d/e";
+  const path p3 = p2;
+  p1.clear();
+  p1 = p2;
+  __gnu_test::compare_paths(p1, p2);
+  __gnu_test::compare_paths(p1, p3);
+  __gnu_test::compare_paths(p2, p3);
+}
+
 int
 main()
 {
   test01();
   test02();
   test03();
+  test04();
 }

diff --git a/libstdc++-v3/testsuite/util/testsuite_fs.h b/libstdc++-v3/testsuite/util/testsuite_fs.h
index baba90eaa0cca0ffa26c9689f63cf30fc0da4962..b2a5ee6e65528d7f86ffafea27a966d2e82b812c 100644 (file)
--- a/libstdc++-v3/testsuite/util/testsuite_fs.h
+++ b/libstdc++-v3/testsuite/util/testsuite_fs.h
@@ -30,6 +30,7 @@ namespace test_fs = std::filesystem;
 #include <experimental/filesystem>
 namespace test_fs = std::experimental::filesystem;
 #endif
+#include <algorithm>
 #include <fstream>
 #include <string>
 #include <cstdio>
@@ -62,10 +63,15 @@ namespace __gnu_test
     PATH_CHK( p1, p2, is_relative );
     auto d1 = std::distance(p1.begin(), p1.end());
     auto d2 = std::distance(p2.begin(), p2.end());
-    if( d1 != d2 )
+    if (d1 != d2)
       throw test_fs::filesystem_error(
-         "distance(begin, end)", p1, p2,
+         "distance(begin1, end1) != distance(begin2, end2)", p1, p2,
          std::make_error_code(std::errc::invalid_argument) );
+    if (!std::equal(p1.begin(), p1.end(), p2.begin(), p2.end()))
+      throw test_fs::filesystem_error(
+         "!equal(begin1, end1, begin2, end2)", p1, p2,
+         std::make_error_code(std::errc::invalid_argument) );
+
   }
 
   const std::string test_paths[] = {