38 changes: 29 additions & 9 deletions src/path.cpp
View file
Expand Up @@ -198,20 +198,30 @@ BOOST_FILESYSTEM_DECL void path::append_v4(path const& p)
size_type that_root_name_size = 0;
size_type that_root_dir_pos = find_root_directory_start(p.m_pathname.c_str(), that_size, that_root_name_size);

// if (p.is_absolute())
if
(
#if defined(BOOST_WINDOWS_API) && !defined(UNDER_CE)
that_root_name_size > 0 &&
#endif
that_root_dir_pos < that_size
)
{
return_assign:
assign(p);
return;
}

size_type this_root_name_size = 0;
find_root_directory_start(m_pathname.c_str(), m_pathname.size(), this_root_name_size);

// Unlike C++20 std::filesystem, do not assign p if it is absolute. This breaks support for UNC paths on POSIX,
// where `path("//net/foo") / "/bar"` would result in "/bar" instead of "//net/bar".

if
(
that_root_name_size > 0 &&
(that_root_name_size != this_root_name_size || std::memcmp(m_pathname.c_str(), p.m_pathname.c_str(), this_root_name_size * sizeof(value_type)) != 0)
)
{
operator=(p);
return;
goto return_assign;
}

if (that_root_dir_pos < that_size)
Expand Down Expand Up @@ -244,8 +254,19 @@ BOOST_FILESYSTEM_DECL void path::append_v4(const value_type* begin, const value_
size_type that_root_name_size = 0;
size_type that_root_dir_pos = find_root_directory_start(begin, that_size, that_root_name_size);

// Unlike C++20 std::filesystem, do not assign path(begin, end) if it is absolute. This breaks support
// for UNC paths on POSIX, where `path("//net/foo") / "/bar"` would result in "/bar" instead of "//net/bar".
// if (p.is_absolute())
if
(
#if defined(BOOST_WINDOWS_API) && !defined(UNDER_CE)
that_root_name_size > 0 &&
#endif
that_root_dir_pos < that_size
)
{
return_assign:
assign(begin, end);
return;
}

size_type this_root_name_size = 0;
find_root_directory_start(m_pathname.c_str(), m_pathname.size(), this_root_name_size);
Expand All @@ -256,8 +277,7 @@ BOOST_FILESYSTEM_DECL void path::append_v4(const value_type* begin, const value_
(that_root_name_size != this_root_name_size || std::memcmp(m_pathname.c_str(), begin, this_root_name_size * sizeof(value_type)) != 0)
)
{
m_pathname.assign(begin, end);
return;
goto return_assign;
}

if (that_root_dir_pos < that_size)
Expand Down
2 changes: 1 addition & 1 deletion test/path_test.cpp
View file
Expand Up @@ -695,7 +695,7 @@ void non_member_tests()
PATH_TEST_EQ(path("//net1/foo") / "/bar", "//net1/foo/bar");
#else
PATH_TEST_EQ(path("//net1/foo") / "//net2/bar", "//net2/bar");
PATH_TEST_EQ(path("//net1/foo") / "/bar", "//net1/bar");
PATH_TEST_EQ(path("//net1/foo") / "/bar", "/bar");
#endif
PATH_TEST_EQ(path("//net1/foo") / "bar", "//net1/foo/bar");
}
Expand Down