ucb: webdav-curl: tdf#106955: Open WebDAV resources on which PROPFIND fails

When PROPFIND fails on a WebDAV resource, its IsDocument property
stays undefined, and so stream creation fails. Proposed solution
is to default to IsDocument=true for all WebDAV documents where
we cannot get the property from server.

Such resources also fail to return their locking options, so
defaulting to server properties. When later locking is attempted
on it, the attempt fails with user notification (a dialog saying
that getting information from server failed). Proposed solution
is to check Content-Disposition header in such resources, and in
case it's attachment, disable lock on this resource. The rationale
for this is that "In a regular HTTP response, the Content-Disposition
response header is a header indicating if the content is expected
to be displayed ... as an attachment, that is downloaded and saved
locally" (see MDN:
https://developer.mozilla.org/en/docs/Web/HTTP/Headers/Content-Disposition

Also, Content::getProperties wasn't ready for PROPFIND returning
empty result.

[ port of commit fbc04c97231d629c1b5e9e57203dbe8d8eb06714 ]

Change-Id: If0b4c10ef7b7b108a8779c773c65e25973d32b46
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/123504
Tested-by: Michael Stahl <michael.stahl@allotropia.de>
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

2 files changed, 172 insertions, 108 deletions

diff --git a/ucb/source/ucp/webdav-curl/webdavcontent.cxx b/ucb/source/ucp/webdav-curl/webdavcontent.cxx
index 974867e78685..75f9d0ca2ae9 100644
--- a/ucb/source/ucp/webdav-curl/webdavcontent.cxx
+++ b/ucb/source/ucp/webdav-curl/webdavcontent.cxx
@@ -1260,6 +1260,45 @@ uno::Reference< sdbc::XRow > Content::getPropertyValues(
     return uno::Reference<sdbc::XRow>(xRow);
 }
 
+namespace {
+void GetPropsUsingHeadRequest(DAVResource& resource,
+                              const std::unique_ptr< DAVResourceAccess >& xResAccess,
+                              const std::vector< OUString >& aHTTPNames,
+                              const uno::Reference< ucb::XCommandEnvironment >& xEnv)
+{
+    if (!aHTTPNames.empty())
+    {
+        DAVOptions aDAVOptions;
+        OUString   aTargetURL = xResAccess->getURL();
+        // retrieve the cached options if any
+        aStaticDAVOptionsCache.getDAVOptions(aTargetURL, aDAVOptions);
+
+        // clean cached value of PROPFIND property names
+        // PROPPATCH can change them
+        Content::removeCachedPropertyNames(aTargetURL);
+        // test if HEAD allowed, if not, throw, should be catched immediately
+        // SC_GONE used internally by us, see comment in Content::getPropertyValues
+        // in the catch scope
+        if (aDAVOptions.getHttpResponseStatusCode() != SC_GONE &&
+            !aDAVOptions.isHeadAllowed())
+        {
+            throw DAVException(DAVException::DAV_HTTP_ERROR, "405 Not Implemented", SC_METHOD_NOT_ALLOWED);
+        }
+        // if HEAD is enabled on this site
+        // check if there is a relevant HTTP response status code cached
+        if (aDAVOptions.getHttpResponseStatusCode() != SC_NONE)
+        {
+            // throws exception as if there was a server error, a DAV exception
+            throw DAVException(DAVException::DAV_HTTP_ERROR,
+                aDAVOptions.getHttpResponseStatusText(),
+                aDAVOptions.getHttpResponseStatusCode());
+            // Unreachable
+        }
+
+        xResAccess->HEAD(aHTTPNames, resource, xEnv);
+    }
+}
+}
 
 uno::Reference< sdbc::XRow > Content::getPropertyValues(
                 const uno::Sequence< beans::Property >& rProperties,
@@ -1449,117 +1488,89 @@ uno::Reference< sdbc::XRow > Content::getPropertyValues(
                     aHeaderNames.push_back( "Content-Type" );
                 }
 
-                if ( !aHeaderNames.empty() )
+                if (!aHeaderNames.empty()) try
                 {
-                    DAVOptions aDAVOptions;
-                    OUString   aTargetURL = xResAccess->getURL();
-                    // retrieve the cached options if any
-                    aStaticDAVOptionsCache.getDAVOptions( aTargetURL, aDAVOptions );
-                    try
-                    {
-                        DAVResource resource;
-                        // clean cached value of PROPFIND property names
-                        // PROPPATCH can change them
-                        removeCachedPropertyNames( aTargetURL );
-                        // test if HEAD allowed, if not, throw, will be catched immediately
-                        // SC_GONE used internally by us, see comment below
-                        // in the catch scope
-                        if ( aDAVOptions.getHttpResponseStatusCode() != SC_GONE &&
-                             !aDAVOptions.isHeadAllowed() )
-                        {
-                            throw DAVException( DAVException::DAV_HTTP_ERROR, "405 Not Implemented", SC_METHOD_NOT_ALLOWED );
-                        }
-                        // if HEAD is enabled on this site
-                        // check if there is a relevant HTTP response status code cached
-                        if ( aDAVOptions.getHttpResponseStatusCode() != SC_NONE )
-                        {
-                            // throws exception as if there was a server error, a DAV exception
-                            throw DAVException( DAVException::DAV_HTTP_ERROR,
-                                                aDAVOptions.getHttpResponseStatusText(),
-                                                aDAVOptions.getHttpResponseStatusCode() );
-                            // Unreachable
-                        }
-
-                        xResAccess->HEAD( aHeaderNames, resource, xEnv );
-                        m_bDidGetOrHead = true;
+                    DAVResource resource;
+                    GetPropsUsingHeadRequest(resource, xResAccess, aHeaderNames, xEnv);
+                    m_bDidGetOrHead = true;
 
-                        if (xProps)
-                            xProps->addProperties(
-                                aMissingProps,
-                                ContentProperties( resource ) );
-                        else
-                            xProps.reset ( new ContentProperties( resource ) );
+                    if (xProps)
+                        xProps->addProperties(
+                            aMissingProps,
+                            ContentProperties( resource ) );
+                    else
+                        xProps.reset ( new ContentProperties( resource ) );
 
-                        if ( m_eResourceType == NON_DAV )
-                            xProps->addProperties( aMissingProps,
-                                                   ContentProperties(
-                                                       aUnescapedTitle,
-                                                       false ) );
-                    }
-                    catch ( DAVException const & e )
+                    if (m_eResourceType == NON_DAV)
+                        xProps->addProperties(aMissingProps,
+                            ContentProperties(
+                                aUnescapedTitle,
+                                false));
+                }
+                catch ( DAVException const & e )
+                {
+                    // non "general-purpose servers" may not support HEAD requests
+                    // see http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1.1
+                    // In this case, perform a partial GET only to get the header info
+                    // vid. http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
+                    // WARNING if the server does not support partial GETs,
+                    // the GET will transfer the whole content
+                    bool bError = true;
+                    DAVException aLastException = e;
+                    OUString aTargetURL = xResAccess->getURL();
+
+                    if ( e.getError() == DAVException::DAV_HTTP_ERROR )
                     {
-                        // non "general-purpose servers" may not support HEAD requests
-                        // see http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1.1
-                        // In this case, perform a partial GET only to get the header info
-                        // vid. http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
-                        // WARNING if the server does not support partial GETs,
-                        // the GET will transfer the whole content
-                        bool bError = true;
-                        DAVException aLastException = e;
-
-                        if ( e.getError() == DAVException::DAV_HTTP_ERROR )
+                        // According to the spec. the origin server SHOULD return
+                        // * 405 (Method Not Allowed):
+                        //      the method is known but not allowed for the requested resource
+                        // * 501 (Not Implemented):
+                        //      the method is unrecognized or not implemented
+                        // * 404 (SC_NOT_FOUND)
+                        //      is for google-code server and for MS IIS 10.0 Web server
+                        //      when only GET is enabled
+                        if ( aLastException.getStatus() == SC_NOT_IMPLEMENTED ||
+                             aLastException.getStatus() == SC_METHOD_NOT_ALLOWED ||
+                             aLastException.getStatus() == SC_NOT_FOUND )
                         {
-                            // According to the spec. the origin server SHOULD return
-                            // * 405 (Method Not Allowed):
-                            //      the method is known but not allowed for the requested resource
-                            // * 501 (Not Implemented):
-                            //      the method is unrecognized or not implemented
-                            // * 404 (SC_NOT_FOUND)
-                            //      is for google-code server and for MS IIS 10.0 Web server
-                            //      when only GET is enabled
-                            if ( aLastException.getStatus() == SC_NOT_IMPLEMENTED ||
-                                 aLastException.getStatus() == SC_METHOD_NOT_ALLOWED ||
-                                 aLastException.getStatus() == SC_NOT_FOUND )
-                            {
-                                SAL_WARN( "ucb.ucp.webdav", "HEAD probably not implemented: fall back to a partial GET" );
-                                aStaticDAVOptionsCache.setHeadAllowed( aTargetURL, false );
-                                lcl_sendPartialGETRequest( bError,
-                                                           aLastException,
-                                                           aMissingProps,
-                                                           aHeaderNames,
-                                                           xResAccess,
-                                                           xProps,
-                                                           xEnv );
-                                m_bDidGetOrHead = !bError;
-                            }
+                            SAL_WARN( "ucb.ucp.webdav", "HEAD probably not implemented: fall back to a partial GET" );
+                            aStaticDAVOptionsCache.setHeadAllowed( aTargetURL, false );
+                            lcl_sendPartialGETRequest( bError,
+                                                       aLastException,
+                                                       aMissingProps,
+                                                       aHeaderNames,
+                                                       xResAccess,
+                                                       xProps,
+                                                       xEnv );
+                            m_bDidGetOrHead = !bError;
                         }
+                    }
 
-                        if ( bError )
-                        {
-                            DAVOptions aDAVOptionsException;
-
-                            aDAVOptionsException.setURL( aTargetURL );
-                            // check if the error was SC_NOT_FOUND, meaning that the
-                            // GET fall back didn't succeeded and the element is really missing
-                            // we will consider the resource SC_GONE (410) for some time
-                            // we use SC_GONE because has the same meaning of SC_NOT_FOUND (404)
-                            // see:
-                            // <https://tools.ietf.org/html/rfc7231#section-6.5.9> (retrieved 2016-10-09)
-                            // apparently it's not used to mark the missing HEAD method (so far...)
-                            sal_uInt16 ResponseStatusCode =
-                                ( aLastException.getStatus() == SC_NOT_FOUND ) ?
-                                SC_GONE :
-                                aLastException.getStatus();
-                            aDAVOptionsException.setHttpResponseStatusCode( ResponseStatusCode );
-                            aDAVOptionsException.setHttpResponseStatusText( aLastException.getData() );
-                            aStaticDAVOptionsCache.addDAVOptions( aDAVOptionsException,
-                                                                  m_nOptsCacheLifeNotFound );
+                    if ( bError )
+                    {
+                        DAVOptions aDAVOptionsException;
+
+                        aDAVOptionsException.setURL( aTargetURL );
+                        // check if the error was SC_NOT_FOUND, meaning that the
+                        // GET fall back didn't succeeded and the element is really missing
+                        // we will consider the resource SC_GONE (410) for some time
+                        // we use SC_GONE because has the same meaning of SC_NOT_FOUND (404)
+                        // see:
+                        // <https://tools.ietf.org/html/rfc7231#section-6.5.9> (retrieved 2016-10-09)
+                        // apparently it's not used to mark the missing HEAD method (so far...)
+                        sal_uInt16 ResponseStatusCode =
+                            ( aLastException.getStatus() == SC_NOT_FOUND ) ?
+                            SC_GONE :
+                            aLastException.getStatus();
+                        aDAVOptionsException.setHttpResponseStatusCode( ResponseStatusCode );
+                        aDAVOptionsException.setHttpResponseStatusText( aLastException.getData() );
+                        aStaticDAVOptionsCache.addDAVOptions( aDAVOptionsException,
+                                                              m_nOptsCacheLifeNotFound );
 
-                            if ( !shouldAccessNetworkAfterException( aLastException ) )
-                            {
-                                cancelCommandExecution( aLastException, xEnv );
-                                // unreachable
-                            }
+                        if ( !shouldAccessNetworkAfterException( aLastException ) )
+                        {
+                            cancelCommandExecution( aLastException, xEnv );
+                            // unreachable
                         }
                     }
                 }
@@ -1642,6 +1653,22 @@ uno::Reference< sdbc::XRow > Content::getPropertyValues(
                     uno::makeAny( aDate ),
                     true );
             }
+            // If WebDAV didn't return the resource type, assume default
+            // This happens e.g. for lists exported by SharePoint
+            else if ( (*it) == "IsFolder" )
+            {
+                xProps->addProperty(
+                    (*it),
+                    uno::makeAny( false ),
+                    true );
+            }
+            else if ( (*it) == "IsDocument" )
+            {
+                xProps->addProperty(
+                    (*it),
+                    uno::makeAny( true ),
+                    true );
+            }
         }
     }
 
@@ -2981,8 +3008,6 @@ Content::ResourceType Content::resourceTypeForLocks(
         std::unique_ptr< ContentProperties > xProps;
         if (m_xCachedProps)
         {
-            std::unique_ptr< ContentProperties > xCachedProps;
-            xCachedProps.reset( new ContentProperties(*m_xCachedProps) );
             uno::Sequence< ucb::LockEntry > aSupportedLocks;
             if ( m_xCachedProps->getValue( DAVProperties::SUPPORTEDLOCK )
                  >>= aSupportedLocks )            //get the cached value for supportedlock
@@ -3073,6 +3098,42 @@ Content::ResourceType Content::resourceTypeForLocks(
                                 }
                             }
                         }
+                        else
+                        {
+                            // PROPFIND failed; check if HEAD contains Content-Disposition: attachment (RFC1806, HTTP/1.1 19.5.1),
+                            // which supposedly means no lock for the resource (happens e.g. with SharePoint exported lists)
+                            OUString sContentDisposition;
+                            // First, check cached properties
+                            if (m_xCachedProps)
+                            {
+                                if ((m_xCachedProps->getValue("Content-Disposition") >>= sContentDisposition)
+                                    && sContentDisposition.startsWithIgnoreAsciiCase("attachment"))
+                                {
+                                    eResourceTypeForLocks = DAV_NOLOCK;
+                                    wasSupportedlockFound = true;
+                                }
+                            }
+                            // If no data in cache, try HEAD request
+                            if (sContentDisposition.isEmpty() && !m_bDidGetOrHead) try
+                            {
+                                DAVResource resource;
+                                GetPropsUsingHeadRequest(resource, rResAccess, {"Content-Disposition"}, Environment);
+                                m_bDidGetOrHead = true;
+                                for (const auto& it : resource.properties)
+                                {
+                                    if (it.Name.equalsIgnoreAsciiCase("Content-Disposition"))
+                                    {
+                                        if ((it.Value >>= sContentDisposition) && sContentDisposition.equalsIgnoreAsciiCase("attachment"))
+                                        {
+                                            eResourceTypeForLocks = DAV_NOLOCK;
+                                            wasSupportedlockFound = true;
+                                        }
+                                        break;
+                                    }
+                                }
+                            }
+                            catch (...){}
+                        }
                         // check if this is still only a DAV_NOLOCK
                         // a fallback for resources that do not have DAVProperties::SUPPORTEDLOCK property
                         // we check for the returned OPTION if LOCK is allowed on the resource
diff --git a/ucb/source/ucp/webdav-curl/webdavcontentcaps.cxx b/ucb/source/ucp/webdav-curl/webdavcontentcaps.cxx
index e3ece1b3d8fc..f4bef01c631b 100644
--- a/ucb/source/ucp/webdav-curl/webdavcontentcaps.cxx
+++ b/ucb/source/ucp/webdav-curl/webdavcontentcaps.cxx
@@ -319,10 +319,13 @@ uno::Sequence< beans::Property > Content::getProperties(
                     props = aPropsNames.getPropertiesNames();
                 }
 
-                // Note: vector always contains exactly one resource info, because
+                // Note: vector should contain exactly one resource info, because
                 //       we used a depth of DAVZERO for PROPFIND.
-                aPropSet.insert( (*props.begin()).properties.begin(),
-                                 (*props.begin()).properties.end() );
+                if (props.size() == 1)
+                {
+                    aPropSet.insert( (*props.begin()).properties.begin(),
+                                     (*props.begin()).properties.end() );
+                }
             }
             catch ( DAVException const & )
             {