tdf#116420: Windows: Test if a filepath redirects to a WebDAV resource

In Windows, filesystem redirectors can map WebDAV resources to UNC
paths, or to drive-based "local" paths; so a WebDAV URI of the form
"http://WebDADServer/root/directory/File.ext" may be accessed using
"\\WebDADServer\root\directory\File.ext" or "Z:\directory\File.ext".

When using these paths, failure to create a lockfile aside the opened
document should not be considered an error; so this patch checks for
this.

Regression from commit 6ca3b364.

Change-Id: I1de55b66447dc91d22b6d2b5b121de96bf32e4ee
Reviewed-on: https://gerrit.libreoffice.org/53070Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

include/tools/fileutil.hxx

+/* -*- 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/.
+ */
+
+#ifndef INCLUDED_TOOLS_FILEUTIL_HXX
+#define INCLUDED_TOOLS_FILEUTIL_HXX
+
+#include <tools/toolsdllapi.h>
+
+class INetURLObject;
+
+namespace tools
+{
+// Tests if the path is a UNC or local (drive-based) path that redirects to
+// a WebDAV resource (e.g., using redirectors on Windows).
+// Currently only implemented for Windows; on other platforms, returns false.
+TOOLS_DLLPUBLIC bool IsMappedWebDAVPath(const INetURLObject& aURL);
+}
+
+#endif // INCLUDED_TOOLS_FILEUTIL_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sfx2/source/doc/docfile.cxx

@@ -72,6 +72,7 @@
 #include <com/sun/star/security/DocumentDigitalSignatures.hpp>
 #include <o3tl/make_unique.hxx>
 #include <tools/urlobj.hxx>
+#include <tools/fileutil.hxx>
 #include <unotools/configmgr.hxx>
 #include <unotools/tempfile.hxx>
 #include <comphelper/fileurl.hxx>
@@ -1305,7 +1306,13 @@ SfxMedium::LockFileResult SfxMedium::LockOrigFileOnDemand( bool bLoading, bool b
                                 }
                                 catch (const uno::Exception&)
                                 {
-                                    if (bLoading && !bNoUI)
+                                    if (tools::IsMappedWebDAVPath(GetURLObject()))
+                                    {
+                                        // This is a path that redirects to a WebDAV resource;
+                                        // so failure creating lockfile is not an error here.
+                                        bResult = true;
+                                    }
+                                    else if (bLoading && !bNoUI)
                                     {
                                         bIoErr = true;
                                         ShowLockFileProblemDialog(MessageDlg::LockFileIgnore);

tools/Library_tl.mk

@@ -47,6 +47,7 @@ $(eval $(call gb_Library_add_exception_objects,tl,\
     tools/source/datetime/tdate \
     tools/source/datetime/ttime \
     tools/source/debug/debug \
+    tools/source/fsys/fileutil \
     tools/source/fsys/urlobj \
     tools/source/fsys/wldcrd \
     tools/source/generic/b3dtrans \

tools/source/fsys/fileutil.cxx

+/* -*- 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/.
+ */
+
+#include <tools/fileutil.hxx>
+#include <tools/urlobj.hxx>
+#if defined _WIN32
+#include <osl/file.hxx>
+#include <string.h>
+#include <o3tl/char16_t2wchar_t.hxx>
+#include <o3tl/make_unique.hxx>
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#endif
+
+namespace tools
+{
+bool IsMappedWebDAVPath(const INetURLObject& aURL)
+{
+#if defined _WIN32
+    if (aURL.GetProtocol() == INetProtocol::File)
+    {
+        OUString sURL = aURL.GetMainURL(INetURLObject::DecodeMechanism::NONE);
+        OUString aSystemPath;
+        if (osl::FileBase::getSystemPathFromFileURL(sURL, aSystemPath) == osl::FileBase::E_None)
+        {
+            DWORD nSize = MAX_PATH;
+            auto bufUNC(o3tl::make_unique<char[]>(nSize));
+            DWORD nResult = WNetGetUniversalNameW(o3tl::toW(aSystemPath.getStr()),
+                                                  UNIVERSAL_NAME_INFO_LEVEL, bufUNC.get(), &nSize);
+            if (nResult == ERROR_MORE_DATA)
+            {
+                bufUNC = o3tl::make_unique<char[]>(nSize);
+                nResult = WNetGetUniversalNameW(o3tl::toW(aSystemPath.getStr()),
+                                                UNIVERSAL_NAME_INFO_LEVEL, bufUNC.get(), &nSize);
+            }
+            if (nResult == NO_ERROR || nResult == ERROR_BAD_DEVICE)
+            {
+                NETRESOURCEW aReq{};
+                if (nResult == ERROR_BAD_DEVICE) // The path could already be an UNC
+                    aReq.lpRemoteName = const_cast<LPWSTR>(o3tl::toW(aSystemPath.getStr()));
+                else
+                {
+                    auto pInfo = reinterpret_cast<LPUNIVERSAL_NAME_INFOW>(bufUNC.get());
+                    aReq.lpRemoteName = pInfo->lpUniversalName;
+                }
+                nSize = 1024;
+                auto bufInfo(o3tl::make_unique<char[]>(nSize));
+                LPWSTR pSystem = nullptr;
+                nResult = WNetGetResourceInformationW(&aReq, bufInfo.get(), &nSize, &pSystem);
+                if (nResult == ERROR_MORE_DATA)
+                {
+                    bufInfo = o3tl::make_unique<char[]>(nSize);
+                    nResult = WNetGetResourceInformationW(&aReq, bufInfo.get(), &nSize, &pSystem);
+                }
+                if (nResult == NO_ERROR)
+                {
+                    LPNETRESOURCEW pInfo = reinterpret_cast<LPNETRESOURCEW>(bufInfo.get());
+                    if (wcscmp(pInfo->lpProvider, L"Web Client Network") == 0)
+                        return true;
+                }
+            }
+        }
+    }
+#else
+    (void)aURL;
+#endif
+    return false;
+}
+
+} // namespace tools
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */