1 files changed, 109 insertions, 0 deletions
diff --git a/tools/source/misc/pathutils.cxx b/tools/source/misc/pathutils.cxx
new file mode 100644
index 0000000000..706740a320
--- /dev/null
+++ b/tools/source/misc/pathutils.cxx
@@ -0,0 +1,109 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/config.h>
+
+#if defined(_WIN32)
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <o3tl/safeint.hxx>
+#include <sal/types.h>
+#include <tools/pathutils.hxx>
+
+namespace tools {
+
+WCHAR * filename(WCHAR * path) {
+    WCHAR * f = path;
+    for (WCHAR * p = path;;) {
+        switch (*p++) {
+        case L'\0':
+            return f;
+        case L'\\':
+            f = p;
+            break;
+        }
+    }
+}
+
+WCHAR * buildPath(
+    WCHAR * path, WCHAR const * frontBegin, WCHAR const * frontEnd,
+    WCHAR const * backBegin, std::size_t backLength)
+{
+    // Remove leading ".." segments in the second path together with matching
+    // segments in the first path that are neither empty nor "." nor ".." nor
+    // end in ":" (which is not foolproof, as it can erroneously erase the start
+    // of a UNC path, but only if the input is bad data):
+    while (backLength >= 2 && backBegin[0] == L'.' && backBegin[1] == L'.' &&
+           (backLength == 2 || backBegin[2] == L'\\'))
+    {
+        if (frontEnd - frontBegin < 2 || frontEnd[-1] != L'\\' ||
+            frontEnd[-2] == L'\\' || frontEnd[-2] == L':' ||
+            (frontEnd[-2] == L'.' &&
+             (frontEnd - frontBegin < 3 || frontEnd[-3] == L'\\' ||
+              (frontEnd[-3] == L'.' &&
+               (frontEnd - frontBegin < 4 || frontEnd[-4] == L'\\')))))
+        {
+            break;
+        }
+        WCHAR const * p = frontEnd - 1;
+        while (p != frontBegin && p[-1] != L'\\') {
+            --p;
+        }
+        if (p == frontBegin) {
+            break;
+        }
+        frontEnd = p;
+        if (backLength == 2) {
+            backBegin += 2;
+            backLength -= 2;
+        } else {
+            backBegin += 3;
+            backLength -= 3;
+        }
+    }
+    if (backLength <
+        o3tl::make_unsigned(MAX_PATH - (frontEnd - frontBegin)))
+    {
+        WCHAR * p;
+        if (frontBegin == path) {
+            p = const_cast< WCHAR * >(frontEnd);
+        } else {
+            p = path;
+            while (frontBegin != frontEnd) {
+                *p++ = *frontBegin++;
+            }
+        }
+        for (; backLength > 0; --backLength) {
+            *p++ = *backBegin++;
+        }
+        *p = L'\0';
+        return p;
+    } else {
+        SetLastError(ERROR_FILENAME_EXCED_RANGE);
+        return nullptr;
+    }
+}
+
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */