tdf#83531 Opening WebDAV URL WebDav fails if write is restricted

Happened because LOCK method was not allowed without credentials.

Change-Id: I7b204e67079791a08211410ced4b0b4f015d524a
Reviewed-on: https://gerrit.libreoffice.org/17856
Reviewed-by: Jan Holesovsky <kendy@collabora.com>
Tested-by: Jan Holesovsky <kendy@collabora.com>

sfx2/source/doc/docfile.cxx

@@ -42,6 +42,7 @@
 #include <com/sun/star/ucb/CommandFailedException.hpp>
 #include <com/sun/star/ucb/CommandAbortedException.hpp>
 #include <com/sun/star/ucb/InteractiveLockingLockedException.hpp>
+#include <com/sun/star/ucb/InteractiveNetworkWriteException.hpp>
 #include <com/sun/star/ucb/Lock.hpp>
 #include <com/sun/star/ucb/XCommandEnvironment.hpp>
 #include <com/sun/star/ucb/XContentIdentifierFactory.hpp>
@@ -1010,6 +1011,19 @@ void SfxMedium::LockOrigFileOnDemand( bool bLoading, bool bNoUI )
                                 bUIStatus = ShowLockedDocumentDialog( aLockData, bLoading, false );
                             }
                         }
+                        catch( ucb::InteractiveNetworkWriteException& )
+                        {
+                            // This catch it's not really needed, here just for the sake of documentation on the behaviour.
+                            // This is the most likely reason:
+                            // - the remote site is a WebDAV with special configuration: read/only for read operations
+                            //   and read/write for write operations, the user is not allowed to lock/write and
+                            //   she cancelled the credentials request.
+                            //   this is not actually an error, but the exception is sent directly from ucb, avoiding the automatic
+                            //   management that takes part in cancelCommandExecution()
+                            // Unfortunately there is no InteractiveNetwork*Exception available to signal this more correctly
+                            // since it mostly happens on read/only part of webdav, this can be the most correct
+                            // exception available
+                        }
                         catch( uno::Exception& )
                         {}
                     }

ucb/source/ucp/webdav-neon/webdavcontent.cxx

@@ -2990,6 +2990,28 @@ void Content::lock(
                         false );
             }
             break;
+            case DAVException::DAV_HTTP_AUTH:
+            {
+                SAL_WARN( "ucb.ucp.webdav", "lock: DAVException Authentication error - URL: <"
+                          << m_xIdentifier->getContentIdentifier() << ">" );
+                // this could mean:
+                // - interaction handler for credential management not present (happens, depending
+                //   on the LO framework processing)
+                // - the remote site is a WebDAV with special configuration: read/only for read operations
+                //   and read/write for write operations, the user is not allowed to lock/write and
+                //   she cancelled the credentials request.
+                //   this is not actually an error, but the exception is sent directly from here, avoiding the automatic
+                //   management that takes part in cancelCommandExecution() below
+                // Unfortunately there is no InteractiveNetwork*Exception available to signal this
+                // since it mostly happens on read/only part of webdav, this appears to be the most correct exception available
+                throw
+                    ucb::InteractiveNetworkWriteException(
+                        OUString( "Authentication error while tring to lock! Write only WebDAV perhaps?" ),
+                        static_cast< cppu::OWeakObject * >( this ),
+                        task::InteractionClassification_ERROR,
+                        e.getData() );
+            }
+            break;
             case DAVException::DAV_HTTP_ERROR:
                 //grab the error code
                 switch( e.getStatus() )