diff --git a/SeedDMS_Core/Core/inc.ClassDMS.php b/SeedDMS_Core/Core/inc.ClassDMS.php
index 959057ba6..4f06d1ef9 100644
--- a/SeedDMS_Core/Core/inc.ClassDMS.php
+++ b/SeedDMS_Core/Core/inc.ClassDMS.php
@@ -2210,13 +2210,17 @@ class SeedDMS_Core_DMS {
 
 						// Send the complete search query to the database.
 						$resArr = $this->db->getResultArray($searchQuery);
+						if($resArr === false)
+							return false;
 					} else {
 						$resArr = array();
 					}
 				} else {
 					// Send the complete search query to the database.
 					$resArr = $this->db->getResultArray($searchQuery);
-				}
+					if($resArr === false)
+						return false;
+					}
 
 				// ------------------- Ausgabe der Ergebnisse ----------------------------
 				$numResults = count($resArr);
diff --git a/SeedDMS_Core/package.xml b/SeedDMS_Core/package.xml
index 48138af1b..85277b185 100644
--- a/SeedDMS_Core/package.xml
+++ b/SeedDMS_Core/package.xml
@@ -1582,6 +1582,23 @@ add lots of DocBlocks from merge request #8
 add SeedDMS_Core_AttributeDefinition::removeValue()
    </notes>
   </release>
+  <release>
+   <date>2018-04-11</date>
+   <time>09:19:24</time>
+   <version>
+    <release>5.1.8</release>
+    <api>5.1.8</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <license uri="http://opensource.org/licenses/gpl-license">GPL License</license>
+   <notes>
+SeedDMS_Core_DMS::search() returns false in case of an error
+do not use views in DBAccessPDO by default anymore, use temp. tables
+   </notes>
+  </release>
   <release>
    <date>2017-02-28</date>
    <time>06:34:50</time>
diff --git a/conf/settings.xml.template b/conf/settings.xml.template
index ea35e3c2f..452c847fe 100644
--- a/conf/settings.xml.template
+++ b/conf/settings.xml.template
@@ -71,6 +71,9 @@
       calendarDefaultView = "y"
       firstDayOfWeek = "0"
     />
+    <webdav
+      enableWebdavReplaceDoc="true"
+    />
   </site>
   <system>
     <!--
diff --git a/doc/README.WebDAV b/doc/README.WebDAV
index 4211bae73..12670a283 100644
--- a/doc/README.WebDAV
+++ b/doc/README.WebDAV
@@ -13,17 +13,45 @@ and its content, while a file system knows just files.
 In SeedDMS a document is uniquely identified
 by its document id and not neccessarily by its name. A filesystem
 requires a unique paths for each file. Two identical files in the
-same folder are not possible. SeedDMS can handle identifcally named
+same folder are not possible. SeedDMS can handle identically named
 documents in one folder. In order to prevent any problems arising from
 this, you should always disallow identical document names in the
 settings. By definition a file in WebDAV is mapped on the latest
 version of a document in SeedDMS. There is no way to access previous
-versions of a document via WebDAV. Whenever you modify a file,
+versions of a document via WebDAV. Whenever you modify a file and
+upload it with the web gui,
 a new version will be created. Unfortunately, this has some very
-nasty side effects when you often save a file, because any save
-operation will create a new version. This is because the WebDAV
-server replaces the content of document instead of creating a new
-version if a document is saved again.
+nasty side effects when you edit a document version via WebDAV and
+often save it, because any save
+operation will create a new version. This is why the WebDAV
+server has a configuration option which allows to either replace
+the content of document or creating a new
+version if a document is saved.
+
+Configuring davfs2
+===================
+
+On Linux it is quite simple to mount the SeedDMS WebDAV server with
+davfs2. Just place a line like the following in your /etc/fstab
+
+http://seeddms.your-domain.com/webdav/index.php /media/webdav davfs noauto,user,rw,uid=1000,gid=1000
+
+and mount it as root with
+
+mount /media/webdav davfs
+
+You may as well want to configure davfs2 in /etc/davfs2/davfs2.conf by setting
+
+[/media/webdav]
+use_locks 0
+gui_optimize 1
+
+and possibly add your login data to /etc/davfs2/secrets
+
+/media/webdav admin secret
+
+Making applications work with WebDAV
+=====================================
 
 Various programms have differnt strategies to save files to disk and
 prevent data lost under all circumstances. Those strategies often don't
@@ -35,19 +63,31 @@ VIM
 
 vim does a lot more than just reading and writing the file you want
 to edit. It creates swap and backup files for data recovery if vim crashes
-or is being kill unexpectivly. On a low bandwidth connection this can
+or is being killed unexpectively. On a low bandwidth connection this can
 slow down the editing. For that reason you should either not create the
 swap file at all or create it outside the WebDAV server. A second problem
 arises from how vim modifіes the file you are editing. Before a file
-is saved a backup is created and the new content is written into a new
-file with the name of the original file. On a file system you
-won't see a difference between the file before and after saveing, though
-is actually a new one. In SeedDMS you won't notice a difference either
-if just looking at the document name. It's still the same, but the
+is saved a backup is created by renaming the file to the same name with a
+'~' at the end and writing the file content into a new
+file with the name of the original file. Afterwards vim deleteѕ the backup
+file. On a regular file system you
+won't see a difference between the file before and after saving, though
+it is actually a new one. In SeedDMS you won't notice a difference either
+by just looking at the document name. It's still the same, but the
 document id has changed. So saving a document will delete the
 old document and create a new one instead of creating a new version of
 the old document. If you don't want this behaviour, then tell vim
-to not create the backup. Creating the backup file in a directory
-outside of WebDAV doesn't help in this case.
+to not create the backup file. You can do that by either passing additional
+parameters to vim
 
-vi "+set nobackup" "+set nobackuwrite" -n test.txt
+vi "+set nobackup" "+set nowritebackup" -n test.txt
+
+or by setting them in your .vimrc
+
+set nobackup
+set nowritebackup
+set noswapfile
+
+Creating the backup file in a directory outside of WebDAV doesn't help in
+this case, because it still does the file renaming which is turned of by
+'nowritebackup'.
diff --git a/inc/inc.ClassSettings.php b/inc/inc.ClassSettings.php
index b0750238a..8824acaf5 100644
--- a/inc/inc.ClassSettings.php
+++ b/inc/inc.ClassSettings.php
@@ -204,6 +204,8 @@ class Settings { /* {{{ */
 	var $_maxUploadSize = 0;
 	// enable/disable users images
 	var $_enableUserImage = false;
+	// enable/disable replacing documents by webdav
+	var $_enableWebdavReplaceDoc = true;
 	// enable/disable calendar
 	var $_enableCalendar = true;
 	// calendar default view ("w" for week,"m" for month,"y" for year)
@@ -509,56 +511,67 @@ class Settings { /* {{{ */
 		$this->_libraryFolder = intval($tab["libraryFolder"]);
 		$this->_defaultDocPosition = strval($tab["defaultDocPosition"]);
 
+		// XML Path: /configuration/site/calendar
+		$node = $xml->xpath('/configuration/site/webdav');
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_enableWebdavReplaceDoc = Settings::boolVal($tab["enableWebdavReplaceDoc"]);
+		}
+
 		// XML Path: /configuration/site/calendar
 		$node = $xml->xpath('/configuration/site/calendar');
-		$tab = $node[0]->attributes();
-		$this->_enableCalendar = Settings::boolVal($tab["enableCalendar"]);
-		$this->_calendarDefaultView = strval($tab["calendarDefaultView"]);
-		$this->_firstDayOfWeek = intval($tab["firstDayOfWeek"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_enableCalendar = Settings::boolVal($tab["enableCalendar"]);
+			$this->_calendarDefaultView = strval($tab["calendarDefaultView"]);
+			$this->_firstDayOfWeek = intval($tab["firstDayOfWeek"]);
+		}
 
 		// XML Path: /configuration/system/server
 		$node = $xml->xpath('/configuration/system/server');
-		$tab = $node[0]->attributes();
-		$this->_rootDir = strval($tab["rootDir"]);
-		$this->_httpRoot = strval($tab["httpRoot"]);
-		$this->_contentDir = strval($tab["contentDir"]);
-		if($this->_contentDir && substr($this->_contentDir, -1, 1) != DIRECTORY_SEPARATOR)
-			$this->_contentDir .= DIRECTORY_SEPARATOR;
-		$this->_cacheDir = strval($tab["cacheDir"]);
-		$this->_stagingDir = strval($tab["stagingDir"]);
-		$this->_luceneDir = strval($tab["luceneDir"]);
-		$this->_dropFolderDir = strval($tab["dropFolderDir"]);
-		$this->_backupDir = strval($tab["backupDir"]);
-		$this->_checkOutDir = strval($tab["checkOutDir"]);
-		$this->_createCheckOutDir = Settings::boolVal($tab["createCheckOutDir"]);
-		$this->_repositoryUrl = strval($tab["repositoryUrl"]);
-		$this->_logFileEnable = Settings::boolVal($tab["logFileEnable"]);
-		$this->_logFileRotation = strval($tab["logFileRotation"]);
-		$this->_enableLargeFileUpload = Settings::boolVal($tab["enableLargeFileUpload"]);
-		$this->_partitionSize = strval($tab["partitionSize"]);
-		$this->_maxUploadSize = strval($tab["maxUploadSize"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_rootDir = strval($tab["rootDir"]);
+			$this->_httpRoot = strval($tab["httpRoot"]);
+			$this->_contentDir = strval($tab["contentDir"]);
+			if($this->_contentDir && substr($this->_contentDir, -1, 1) != DIRECTORY_SEPARATOR)
+				$this->_contentDir .= DIRECTORY_SEPARATOR;
+			$this->_cacheDir = strval($tab["cacheDir"]);
+			$this->_stagingDir = strval($tab["stagingDir"]);
+			$this->_luceneDir = strval($tab["luceneDir"]);
+			$this->_dropFolderDir = strval($tab["dropFolderDir"]);
+			$this->_backupDir = strval($tab["backupDir"]);
+			$this->_checkOutDir = strval($tab["checkOutDir"]);
+			$this->_createCheckOutDir = Settings::boolVal($tab["createCheckOutDir"]);
+			$this->_repositoryUrl = strval($tab["repositoryUrl"]);
+			$this->_logFileEnable = Settings::boolVal($tab["logFileEnable"]);
+			$this->_logFileRotation = strval($tab["logFileRotation"]);
+			$this->_enableLargeFileUpload = Settings::boolVal($tab["enableLargeFileUpload"]);
+			$this->_partitionSize = strval($tab["partitionSize"]);
+			$this->_maxUploadSize = strval($tab["maxUploadSize"]);
 
-		// XML Path: /configuration/system/authentication
-		$node = $xml->xpath('/configuration/system/authentication');
-		$tab = $node[0]->attributes();
-		$this->_enableGuestLogin = Settings::boolVal($tab["enableGuestLogin"]);
-		$this->_enableGuestAutoLogin = Settings::boolVal($tab["enableGuestAutoLogin"]);
-		$this->_enable2FactorAuthentication = Settings::boolVal($tab["enable2FactorAuthentication"]);
-		$this->_enablePasswordForgotten = Settings::boolVal($tab["enablePasswordForgotten"]);
-		$this->_passwordStrength = intval($tab["passwordStrength"]);
-		$this->_passwordStrengthAlgorithm = strval($tab["passwordStrengthAlgorithm"]);
-		$this->_passwordExpiration = intval($tab["passwordExpiration"]);
-		$this->_passwordHistory = intval($tab["passwordHistory"]);
-		$this->_loginFailure = intval($tab["loginFailure"]);
-		$this->_autoLoginUser = intval($tab["autoLoginUser"]);
-		$this->_quota = intval($tab["quota"]);
-		$this->_undelUserIds = strval($tab["undelUserIds"]);
-		$this->_encryptionKey = strval($tab["encryptionKey"]);
-		$this->_cookieLifetime = intval($tab["cookieLifetime"]);
-		$this->_defaultAccessDocs = intval($tab["defaultAccessDocs"]);
-		$this->_restricted = Settings::boolVal($tab["restricted"]);
-		$this->_enableUserImage = Settings::boolVal($tab["enableUserImage"]);
-		$this->_disableSelfEdit = Settings::boolVal($tab["disableSelfEdit"]);
+			// XML Path: /configuration/system/authentication
+			$node = $xml->xpath('/configuration/system/authentication');
+			$tab = $node[0]->attributes();
+			$this->_enableGuestLogin = Settings::boolVal($tab["enableGuestLogin"]);
+			$this->_enableGuestAutoLogin = Settings::boolVal($tab["enableGuestAutoLogin"]);
+			$this->_enable2FactorAuthentication = Settings::boolVal($tab["enable2FactorAuthentication"]);
+			$this->_enablePasswordForgotten = Settings::boolVal($tab["enablePasswordForgotten"]);
+			$this->_passwordStrength = intval($tab["passwordStrength"]);
+			$this->_passwordStrengthAlgorithm = strval($tab["passwordStrengthAlgorithm"]);
+			$this->_passwordExpiration = intval($tab["passwordExpiration"]);
+			$this->_passwordHistory = intval($tab["passwordHistory"]);
+			$this->_loginFailure = intval($tab["loginFailure"]);
+			$this->_autoLoginUser = intval($tab["autoLoginUser"]);
+			$this->_quota = intval($tab["quota"]);
+			$this->_undelUserIds = strval($tab["undelUserIds"]);
+			$this->_encryptionKey = strval($tab["encryptionKey"]);
+			$this->_cookieLifetime = intval($tab["cookieLifetime"]);
+			$this->_defaultAccessDocs = intval($tab["defaultAccessDocs"]);
+			$this->_restricted = Settings::boolVal($tab["restricted"]);
+			$this->_enableUserImage = Settings::boolVal($tab["enableUserImage"]);
+			$this->_disableSelfEdit = Settings::boolVal($tab["disableSelfEdit"]);
+		}
 
 		// XML Path: /configuration/system/authentication/connectors/connector
 		// attributs mandatories : type enable
@@ -604,13 +617,15 @@ class Settings { /* {{{ */
 
 		// XML Path: /configuration/system/database
 		$node = $xml->xpath('/configuration/system/database');
-		$tab = $node[0]->attributes();
-		$this->_dbDriver = strval($tab["dbDriver"]);
-		$this->_dbHostname = strval($tab["dbHostname"]);
-		$this->_dbDatabase = strval($tab["dbDatabase"]);
-		$this->_dbUser = strval($tab["dbUser"]);
-		$this->_dbPass = strval($tab["dbPass"]);
-		$this->_doNotCheckDBVersion = Settings::boolVal($tab["doNotCheckDBVersion"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_dbDriver = strval($tab["dbDriver"]);
+			$this->_dbHostname = strval($tab["dbHostname"]);
+			$this->_dbDatabase = strval($tab["dbDatabase"]);
+			$this->_dbUser = strval($tab["dbUser"]);
+			$this->_dbPass = strval($tab["dbPass"]);
+			$this->_doNotCheckDBVersion = Settings::boolVal($tab["doNotCheckDBVersion"]);
+		}
 
 		// XML Path: /configuration/system/smtp
 		$node = $xml->xpath('/configuration/system/smtp');
@@ -639,44 +654,50 @@ class Settings { /* {{{ */
 
 		// XML Path: /configuration/advanced/display
 		$node = $xml->xpath('/configuration/advanced/display');
-		$tab = $node[0]->attributes();
-		$this->_siteDefaultPage = strval($tab["siteDefaultPage"]);
-		$this->_rootFolderID = intval($tab["rootFolderID"]);
-		$this->_titleDisplayHack = Settings::boolval($tab["titleDisplayHack"]);
-		$this->_showMissingTranslations = Settings::boolval($tab["showMissingTranslations"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_siteDefaultPage = strval($tab["siteDefaultPage"]);
+			$this->_rootFolderID = intval($tab["rootFolderID"]);
+			$this->_titleDisplayHack = Settings::boolval($tab["titleDisplayHack"]);
+			$this->_showMissingTranslations = Settings::boolval($tab["showMissingTranslations"]);
+		}
 
 		// XML Path: /configuration/advanced/authentication
 		$node = $xml->xpath('/configuration/advanced/authentication');
-		$tab = $node[0]->attributes();
-		$this->_guestID = intval($tab["guestID"]);
-		$this->_adminIP = strval($tab["adminIP"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_guestID = intval($tab["guestID"]);
+			$this->_adminIP = strval($tab["adminIP"]);
+		}
 
 		// XML Path: /configuration/advanced/edition
 		$node = $xml->xpath('/configuration/advanced/edition');
-		$tab = $node[0]->attributes();
-		$this->_enableAdminRevApp = Settings::boolval($tab["enableAdminRevApp"]);
-		$this->_enableOwnerRevApp = Settings::boolval($tab["enableOwnerRevApp"]);
-		$this->_enableSelfRevApp = Settings::boolval($tab["enableSelfRevApp"]);
-		$this->_enableUpdateRevApp = Settings::boolval($tab["enableUpdateRevApp"]);
-		$this->_enableSelfReceipt = Settings::boolval($tab["enableSelfReceipt"]);
-		$this->_enableAdminReceipt = Settings::boolval($tab["enableAdminReceipt"]);
-		$this->_enableOwnerReceipt = Settings::boolval($tab["enableOwnerReceipt"]);
-		$this->_enableUpdateReceipt = Settings::boolval($tab["enableUpdateReceipt"]);
-		$this->_enableFilterReceipt = Settings::boolval($tab["enableFilterReceipt"]);
-		$this->_presetExpirationDate = strval($tab["presetExpirationDate"]);
-		$this->_initialDocumentStatus = intval($tab["initialDocumentStatus"]);
-		$this->_versioningFileName = strval($tab["versioningFileName"]);
-		$this->_workflowMode = strval($tab["workflowMode"]);
-		$this->_enableReceiptWorkflow = strval($tab["enableReceiptWorkflow"]);
-		$this->_enableRevisionWorkflow = strval($tab["enableRevisionWorkflow"]);
-		$this->_enableRevisionOnVoteReject = strval($tab["enableRevisionOnVoteReject"]);
-		$this->_allowReviewerOnly = Settings::boolval($tab["allowReviewerOnly"]);
-		$this->_enableVersionDeletion = Settings::boolval($tab["enableVersionDeletion"]);
-		$this->_enableVersionModification = Settings::boolval($tab["enableVersionModification"]);
-		$this->_enableDuplicateDocNames = Settings::boolval($tab["enableDuplicateDocNames"]);
-		$this->_overrideMimeType = Settings::boolval($tab["overrideMimeType"]);
-		$this->_advancedAcl = Settings::boolval($tab["advancedAcl"]);
-		$this->_removeFromDropFolder = Settings::boolval($tab["removeFromDropFolder"]);
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_enableAdminRevApp = Settings::boolval($tab["enableAdminRevApp"]);
+			$this->_enableOwnerRevApp = Settings::boolval($tab["enableOwnerRevApp"]);
+			$this->_enableSelfRevApp = Settings::boolval($tab["enableSelfRevApp"]);
+			$this->_enableUpdateRevApp = Settings::boolval($tab["enableUpdateRevApp"]);
+			$this->_enableSelfReceipt = Settings::boolval($tab["enableSelfReceipt"]);
+			$this->_enableAdminReceipt = Settings::boolval($tab["enableAdminReceipt"]);
+			$this->_enableOwnerReceipt = Settings::boolval($tab["enableOwnerReceipt"]);
+			$this->_enableUpdateReceipt = Settings::boolval($tab["enableUpdateReceipt"]);
+			$this->_enableFilterReceipt = Settings::boolval($tab["enableFilterReceipt"]);
+			$this->_presetExpirationDate = strval($tab["presetExpirationDate"]);
+			$this->_initialDocumentStatus = intval($tab["initialDocumentStatus"]);
+			$this->_versioningFileName = strval($tab["versioningFileName"]);
+			$this->_workflowMode = strval($tab["workflowMode"]);
+			$this->_enableReceiptWorkflow = strval($tab["enableReceiptWorkflow"]);
+			$this->_enableRevisionWorkflow = strval($tab["enableRevisionWorkflow"]);
+			$this->_enableRevisionOnVoteReject = strval($tab["enableRevisionOnVoteReject"]);
+			$this->_allowReviewerOnly = Settings::boolval($tab["allowReviewerOnly"]);
+			$this->_enableVersionDeletion = Settings::boolval($tab["enableVersionDeletion"]);
+			$this->_enableVersionModification = Settings::boolval($tab["enableVersionModification"]);
+			$this->_enableDuplicateDocNames = Settings::boolval($tab["enableDuplicateDocNames"]);
+			$this->_overrideMimeType = Settings::boolval($tab["overrideMimeType"]);
+			$this->_advancedAcl = Settings::boolval($tab["advancedAcl"]);
+			$this->_removeFromDropFolder = Settings::boolval($tab["removeFromDropFolder"]);
+		}
 
 		// XML Path: /configuration/advanced/notification
 		$node = $xml->xpath('/configuration/advanced/notification');
@@ -689,18 +710,20 @@ class Settings { /* {{{ */
 
 		// XML Path: /configuration/advanced/server
 		$node = $xml->xpath('/configuration/advanced/server');
-		$tab = $node[0]->attributes();
-		$this->_coreDir = strval($tab["coreDir"]);
-		$this->_luceneClassDir = strval($tab["luceneClassDir"]);
-		$this->_extraPath = strval($tab["extraPath"]);
-		$this->_contentOffsetDir = strval($tab["contentOffsetDir"]);
-		$this->_maxDirID = intval($tab["maxDirID"]);
-		$this->_updateNotifyTime = intval($tab["updateNotifyTime"]);
-		$this->_cmdTimeout = intval($tab["cmdTimeout"]);
-		if (isset($tab["maxExecutionTime"]))
-			$this->_maxExecutionTime = intval($tab["maxExecutionTime"]);
-		else
-			$this->_maxExecutionTime = ini_get("max_execution_time");
+		if($node) {
+			$tab = $node[0]->attributes();
+			$this->_coreDir = strval($tab["coreDir"]);
+			$this->_luceneClassDir = strval($tab["luceneClassDir"]);
+			$this->_extraPath = strval($tab["extraPath"]);
+			$this->_contentOffsetDir = strval($tab["contentOffsetDir"]);
+			$this->_maxDirID = intval($tab["maxDirID"]);
+			$this->_updateNotifyTime = intval($tab["updateNotifyTime"]);
+			$this->_cmdTimeout = intval($tab["cmdTimeout"]);
+			if (isset($tab["maxExecutionTime"]))
+				$this->_maxExecutionTime = intval($tab["maxExecutionTime"]);
+			else
+				$this->_maxExecutionTime = ini_get("max_execution_time");
+		}
 
 		// XML Path: /configuration/system/advanced/converters
 		$convertergroups = $xml->xpath('/configuration/advanced/converters');
@@ -847,6 +870,10 @@ class Settings { /* {{{ */
     $this->setXMLAttributValue($node, "libraryFolder", $this->_libraryFolder);
     $this->setXMLAttributValue($node, "defaultDocPosition", $this->_defaultDocPosition);
 
+    // XML Path: /configuration/site/calendar
+    $node = $this->getXMLNode($xml, '/configuration/site', 'webdav');
+		$this->setXMLAttributValue($node, "enableWebdavReplaceDoc", $this->_enableWebdavReplaceDoc);
+
     // XML Path: /configuration/site/calendar
     $node = $this->getXMLNode($xml, '/configuration/site', 'calendar');
     $this->setXMLAttributValue($node, "enableCalendar", $this->_enableCalendar);
diff --git a/op/op.Settings.php b/op/op.Settings.php
index 8bb128224..277310a5b 100644
--- a/op/op.Settings.php
+++ b/op/op.Settings.php
@@ -105,6 +105,9 @@ if ($action == "saveSettings")
   $settings->_defaultDocPosition = $_POST["defaultDocPosition"];
   $settings->_libraryFolder = intval($_POST["libraryFolder"]);
 
+  // SETTINGS - SITE - WEBDAV
+	$settings->_enableWebdavReplaceDoc = getBoolValue("enableWebdavReplaceDoc");
+
   // SETTINGS - SITE - CALENDAR
   $settings->_enableCalendar = getBoolValue("enableCalendar");
   $settings->_calendarDefaultView = $_POST["calendarDefaultView"];
diff --git a/restapi/index.php b/restapi/index.php
index 5013842d5..39e8ffe9a 100644
--- a/restapi/index.php
+++ b/restapi/index.php
@@ -427,7 +427,7 @@ function createFolder($id) { /* {{{ */
                 if($folder = $parent->addSubFolder($name, $comment, $userobj, 0, $newattrs)) {
 
                     $rec = __getFolderData($folder);
-										$app->response()->status(201);
+                    $app->response()->status(201);
                     $app->response()->header('Content-Type', 'application/json');
                     echo json_encode(array('success'=>true, 'message'=>'', 'data'=>$rec));
                 } else {
@@ -747,10 +747,10 @@ function uploadDocumentFile($documentId) { /* {{{ */
             $app->response()->header('Content-Type', 'application/json');
             echo json_encode(array('success'=>false, 'message'=>'No access', 'data'=>''));
         }
-		} else {
-			  if($document === null)
+    } else {
+        if($document === null)
             $app->response()->status(400);
-				else
+        else
             $app->response()->status(500);
         $app->response()->header('Content-Type', 'application/json');
         echo json_encode(array('success'=>false, 'message'=>'No such document', 'data'=>''));
@@ -1226,6 +1226,10 @@ function doSearch() { /* {{{ */
     if(!$limit = $app->request()->get('limit'))
         $limit = 5;
     $resArr = $dms->search($querystr);
+    if($resArr === false) {
+        $app->response()->header('Content-Type', 'application/json');
+        echo json_encode(array());
+    }
     $entries = array();
     $count = 0;
     if($resArr['folders']) {
@@ -1377,7 +1381,7 @@ function getUsers() { /* {{{ */
     $users = $dms->getAllUsers();
     $data = [];
     foreach($users as $u)
-	    $data[] = __getUserData($u);
+    $data[] = __getUserData($u);
 
     $app->response()->header('Content-Type', 'application/json');
     echo json_encode(array('success'=>true, 'message'=>'', 'data'=>$data));
@@ -1803,12 +1807,12 @@ function changeFolderAccess($id, $operationType, $userOrGroup) { /* {{{ */
 function getCategories() { /* {{{ */
     global $app, $dms, $userobj;
 
-		if(false === ($categories = $dms->getDocumentCategories())) {
+    if(false === ($categories = $dms->getDocumentCategories())) {
         $app->response()->status(500);
-	  		$app->response()->header('Content-Type', 'application/json');
-		  	echo json_encode(array('success'=>false, 'message'=>'Could not get categories', 'data'=>null));
+        $app->response()->header('Content-Type', 'application/json');
+        echo json_encode(array('success'=>false, 'message'=>'Could not get categories', 'data'=>null));
         return;
-		}
+    }
     $data = [];
     foreach($categories as $category)
         $data[] = ['id' => (int)$category->getId(), 'name' => $category->getName()];
diff --git a/views/bootstrap/class.Settings.php b/views/bootstrap/class.Settings.php
index 1b9c9906d..549704f6f 100644
--- a/views/bootstrap/class.Settings.php
+++ b/views/bootstrap/class.Settings.php
@@ -381,6 +381,15 @@ if(!is_writeable($settings->_configFilePath)) {
 				<td><?php $this->printFolderChooserHtml("form1", M_READWRITE, -1, $dms->getFolder($settings->_libraryFolder), 'libraryFolder');?></td>
       </tr>
 
+      <!--
+        -- SETTINGS - SITE - WEBDAV
+      -->
+		 <tr><td></td></tr><tr ><td><b> <?php printMLText("settings_webdav");?></b></td> </tr>
+      <tr title="<?php printMLText("settings_enableWebdavReplaceDoc_desc");?>">
+        <td><?php printMLText("settings_enableWebdavReplaceDoc");?>:</td>
+        <td><input name="enableWebdavReplaceDoc" type="checkbox" <?php if ($settings->_enableWebdavReplaceDoc) echo "checked" ?> /></td>
+      </tr>
+
       <!--
         -- SETTINGS - SITE - CALENDAR
       -->
diff --git a/webdav/webdav.php b/webdav/webdav.php
index c0790d390..e077e4858 100644
--- a/webdav/webdav.php
+++ b/webdav/webdav.php
@@ -91,7 +91,14 @@ class HTTP_WebDAV_Server_SeedDMS extends HTTP_WebDAV_Server
 	 */
 	function log_options($methode, $options) { /* {{{ */
 		if($this->logger) {
-			$this->logger->log($methode.': '.$options['path'], PEAR_LOG_INFO);
+			switch($methode) {
+			case 'MOVE':
+				$msg = $methode.': '.$options['path'].' -> '.$options['dest'];
+				break;
+			default:
+				$msg = $methode.': '.$options['path'];
+			}
+			$this->logger->log($msg, PEAR_LOG_INFO);
 			foreach($options as $key=>$option) {
 				if(is_array($option)) {
 					$this->logger->log($methode.': '.$key.'='.var_export($option, true), PEAR_LOG_DEBUG);
@@ -613,7 +620,8 @@ class HTTP_WebDAV_Server_SeedDMS extends HTTP_WebDAV_Server
 					if($this->user->getID() == $lc->getUser()->getID() &&
 						 $name == $lc->getOriginalFileName() &&
 						 $fileType == $lc->getFileType() &&
-						 $mimetype == $lc->getMimeType()) {
+						 $mimetype == $lc->getMimeType() &&
+						 $settings->_enableWebdavReplaceDoc) {
 						if($this->logger)
 							$this->logger->log('PUT: replacing latest version', PEAR_LOG_INFO);
 						if(!$document->replaceContent($lc->getVersion(), $this->user, $tmpFile, $name, $fileType, $mimetype)) {