win32: use NT-prefixed "\\?\" paths

When turning UTF-8 paths into UCS-2 paths for Windows, always use
the \\?\-prefixed paths.  Because this bypasses the system's
path canonicalization, handle the canonicalization functions ourselves.

We must:
 1. always use a backslash as a directory separator
 2. only use a single backslash between directories
 3. not rely on the system to translate "." and ".." in paths
 4. remove trailing backslashes, except at the drive root (C:\)

1 files changed, 190 insertions, 0 deletions

diff --git a/tests/path/win32.c b/tests/path/win32.c
new file mode 100644
index 000000000..ef0b5d2f2
--- /dev/null
+++ b/tests/path/win32.c
@@ -0,0 +1,190 @@
+
+#include "clar_libgit2.h"
+#include "path.h"
+
+#ifdef GIT_WIN32
+#include "win32/path_w32.h"
+#endif
+
+void test_utf8_to_utf16(const char *utf8_in, const wchar_t *utf16_expected)
+{
+#ifdef GIT_WIN32
+	git_win32_path path_utf16;
+	int path_utf16len;
+
+	cl_assert((path_utf16len = git_win32_path_from_utf8(path_utf16, utf8_in)) >= 0);
+	cl_assert_equal_wcs(utf16_expected, path_utf16);
+	cl_assert_equal_i(wcslen(utf16_expected), path_utf16len);
+#else
+	GIT_UNUSED(utf8_in);
+	GIT_UNUSED(utf16_expected);
+#endif
+}
+
+void test_path_win32__utf8_to_utf16(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("C:\\", L"\\\\?\\C:\\");
+	test_utf8_to_utf16("c:\\", L"\\\\?\\c:\\");
+	test_utf8_to_utf16("C:/", L"\\\\?\\C:\\");
+	test_utf8_to_utf16("c:/", L"\\\\?\\c:\\");
+#endif
+}
+
+void test_path_win32__removes_trailing_slash(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("C:\\Foo\\", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:\\Foo\\\\", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:\\Foo\\\\", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:/Foo/", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:/Foo///", L"\\\\?\\C:\\Foo");
+#endif
+}
+
+void test_path_win32__squashes_multiple_slashes(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("C:\\\\Foo\\Bar\\\\Foobar", L"\\\\?\\C:\\Foo\\Bar\\Foobar");
+	test_utf8_to_utf16("C://Foo/Bar///Foobar", L"\\\\?\\C:\\Foo\\Bar\\Foobar");
+#endif
+}
+
+void test_path_win32__unc(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("\\\\server\\c$\\unc\\path", L"\\\\?\\UNC\\server\\c$\\unc\\path");
+	test_utf8_to_utf16("//server/git/style/unc/path", L"\\\\?\\UNC\\server\\git\\style\\unc\\path");
+#endif
+}
+
+void test_path_win32__honors_max_path(void)
+{
+#ifdef GIT_WIN32
+	git_win32_path path_utf16;
+
+	test_utf8_to_utf16("C:\\This path is 259 chars and is the max length in windows\\0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij",
+		L"\\\\?\\C:\\This path is 259 chars and is the max length in windows\\0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij");
+	test_utf8_to_utf16("\\\\unc\\paths may also be 259 characters including the server\\123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij",
+		L"\\\\?\\UNC\\unc\\paths may also be 259 characters including the server\\123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij");
+
+	cl_check_fail(git_win32_path_from_utf8(path_utf16, "C:\\This path is 260 chars and is sadly too long for windows\\0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij"));
+	cl_check_fail(git_win32_path_from_utf8(path_utf16, "\\\\unc\\paths are also bound by 260 character restrictions\\including the server name portion\\bcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij0123456789abcdefghij"));
+#endif
+}
+
+void test_path_win32__dot_and_dotdot(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("C:\\Foo\\..\\Foobar", L"\\\\?\\C:\\Foobar");
+	test_utf8_to_utf16("C:\\Foo\\Bar\\..\\Foobar", L"\\\\?\\C:\\Foo\\Foobar");
+	test_utf8_to_utf16("C:\\Foo\\Bar\\..\\Foobar\\..", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:\\Foobar\\..", L"\\\\?\\C:\\");
+	test_utf8_to_utf16("C:/Foo/Bar/../Foobar", L"\\\\?\\C:\\Foo\\Foobar");
+	test_utf8_to_utf16("C:/Foo/Bar/../Foobar/../Asdf/", L"\\\\?\\C:\\Foo\\Asdf");
+	test_utf8_to_utf16("C:/Foo/Bar/../Foobar/..", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("C:/Foo/..", L"\\\\?\\C:\\");
+
+	test_utf8_to_utf16("C:\\Foo\\Bar\\.\\Foobar", L"\\\\?\\C:\\Foo\\Bar\\Foobar");
+	test_utf8_to_utf16("C:\\.\\Foo\\.\\Bar\\.\\Foobar\\.\\", L"\\\\?\\C:\\Foo\\Bar\\Foobar");
+	test_utf8_to_utf16("C:/Foo/Bar/./Foobar", L"\\\\?\\C:\\Foo\\Bar\\Foobar");
+	test_utf8_to_utf16("C:/Foo/../Bar/./Foobar/../", L"\\\\?\\C:\\Bar");
+
+	test_utf8_to_utf16("C:\\Foo\\..\\..\\Bar", L"\\\\?\\C:\\Bar");
+#endif
+}
+
+void test_path_win32__absolute_from_no_drive_letter(void)
+{
+#ifdef GIT_WIN32
+	test_utf8_to_utf16("\\Foo", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("\\Foo\\Bar", L"\\\\?\\C:\\Foo\\Bar");
+	test_utf8_to_utf16("/Foo/Bar", L"\\\\?\\C:\\Foo\\Bar");
+#endif
+}
+
+void test_path_win32__absolute_from_relative(void)
+{
+#ifdef GIT_WIN32
+	char cwd_backup[MAX_PATH];
+
+	cl_must_pass(p_getcwd(cwd_backup, MAX_PATH));
+	cl_must_pass(p_chdir("C:/"));
+
+	test_utf8_to_utf16("Foo", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("..\\..\\Foo", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("Foo\\..", L"\\\\?\\C:\\");
+	test_utf8_to_utf16("Foo\\..\\..", L"\\\\?\\C:\\");
+	test_utf8_to_utf16("", L"\\\\?\\C:\\");
+
+	cl_must_pass(p_chdir("C:/Windows"));
+
+	test_utf8_to_utf16("Foo", L"\\\\?\\C:\\Windows\\Foo");
+	test_utf8_to_utf16("Foo\\Bar", L"\\\\?\\C:\\Windows\\Foo\\Bar");
+	test_utf8_to_utf16("..\\Foo", L"\\\\?\\C:\\Foo");
+	test_utf8_to_utf16("Foo\\..\\Bar", L"\\\\?\\C:\\Windows\\Bar");
+	test_utf8_to_utf16("", L"\\\\?\\C:\\Windows");
+
+	cl_must_pass(p_chdir(cwd_backup));
+#endif
+}
+
+void test_canonicalize(const wchar_t *in, const wchar_t *expected)
+{
+#ifdef GIT_WIN32
+	git_win32_path canonical;
+
+	cl_assert(wcslen(in) < MAX_PATH);
+	wcscpy(canonical, in);
+
+	cl_must_pass(git_win32_path_canonicalize(canonical));
+	cl_assert_equal_wcs(expected, canonical);
+#else
+	GIT_UNUSED(in);
+	GIT_UNUSED(expected);
+#endif
+}
+
+void test_path_win32__canonicalize(void)
+{
+#ifdef GIT_WIN32
+	test_canonicalize(L"C:\\Foo\\Bar", L"C:\\Foo\\Bar");
+	test_canonicalize(L"C:\\Foo\\", L"C:\\Foo");
+	test_canonicalize(L"C:\\Foo\\\\", L"C:\\Foo");
+	test_canonicalize(L"C:\\Foo\\..\\Bar", L"C:\\Bar");
+	test_canonicalize(L"C:\\Foo\\..\\..\\Bar", L"C:\\Bar");
+	test_canonicalize(L"C:\\Foo\\..\\..\\..\\..\\", L"C:\\");
+	test_canonicalize(L"C:/Foo/Bar", L"C:\\Foo\\Bar");
+	test_canonicalize(L"C:/", L"C:\\");
+
+	test_canonicalize(L"Foo\\\\Bar\\\\Asdf\\\\", L"Foo\\Bar\\Asdf");
+	test_canonicalize(L"Foo\\\\Bar\\\\..\\\\Asdf\\", L"Foo\\Asdf");
+	test_canonicalize(L"Foo\\\\Bar\\\\.\\\\Asdf\\", L"Foo\\Bar\\Asdf");
+	test_canonicalize(L"Foo\\\\..\\Bar\\\\.\\\\Asdf\\", L"Bar\\Asdf");
+	test_canonicalize(L"\\", L"");
+	test_canonicalize(L"", L"");
+	test_canonicalize(L"Foo\\..\\..\\..\\..", L"");
+	test_canonicalize(L"..\\..\\..\\..", L"");
+	test_canonicalize(L"\\..\\..\\..\\..", L"");
+
+	test_canonicalize(L"\\\\?\\C:\\Foo\\Bar", L"\\\\?\\C:\\Foo\\Bar");
+	test_canonicalize(L"\\\\?\\C:\\Foo\\Bar\\", L"\\\\?\\C:\\Foo\\Bar");
+	test_canonicalize(L"\\\\?\\C:\\\\Foo\\.\\Bar\\\\..\\", L"\\\\?\\C:\\Foo");
+	test_canonicalize(L"\\\\?\\C:\\\\", L"\\\\?\\C:\\");
+	test_canonicalize(L"//?/C:/", L"\\\\?\\C:\\");
+	test_canonicalize(L"//?/C:/../../Foo/", L"\\\\?\\C:\\Foo");
+	test_canonicalize(L"//?/C:/Foo/../../", L"\\\\?\\C:\\");
+
+	test_canonicalize(L"\\\\?\\UNC\\server\\C$\\folder", L"\\\\?\\UNC\\server\\C$\\folder");
+	test_canonicalize(L"\\\\?\\UNC\\server\\C$\\folder\\", L"\\\\?\\UNC\\server\\C$\\folder");
+	test_canonicalize(L"\\\\?\\UNC\\server\\C$\\folder\\", L"\\\\?\\UNC\\server\\C$\\folder");
+	test_canonicalize(L"\\\\?\\UNC\\server\\C$\\folder\\..\\..\\..\\..\\share\\", L"\\\\?\\UNC\\server\\share");
+
+	test_canonicalize(L"\\\\server\\share", L"\\\\server\\share");
+	test_canonicalize(L"\\\\server\\share\\", L"\\\\server\\share");
+	test_canonicalize(L"\\\\server\\share\\\\foo\\\\bar", L"\\\\server\\share\\foo\\bar");
+	test_canonicalize(L"\\\\server\\\\share\\\\foo\\\\bar", L"\\\\server\\share\\foo\\bar");
+	test_canonicalize(L"\\\\server\\share\\..\\foo", L"\\\\server\\foo");
+	test_canonicalize(L"\\\\server\\..\\..\\share\\.\\foo", L"\\\\server\\share\\foo");
+#endif
+}