* Indicate when a preview is unavailable/failed

* Show a little progress "spinner" during the AJAX request

includes/DefaultSettings.php

@@ -1201,7 +1201,7 @@ $wgCacheEpoch = '20030516000000';
  * to ensure that client-side caches don't keep obsolete copies of global
  * styles.
  */
-$wgStyleVersion = '83';
+$wgStyleVersion = '84';
 
 
 # Server-side caching:

includes/Skin.php

@@ -1652,5 +1652,5 @@ END;
 		wfProfileOut( $fname );
 		return $bar;
 	}
-}
-
+	
+}

includes/SpecialUpload.php

@@ -572,7 +572,7 @@ class UploadForm {
 			$output = $wgParser->parse( $revision->getText(), $title, new ParserOptions() );
 			return $output->getText();					
 		}	
-		return '';
+		return wfMsgHtml( 'license-nopreview' );
 	}
 
 	/**
@@ -890,7 +890,8 @@ EOT
 			<tr>" );
 			if( $useAjaxLicencePreview ) {
 				$wgOut->addHtml( "
-					<td id=\"mw-licence-preview\" colspan=\"2\"></td>
+					<td></td>
+					<td id=\"mw-licence-preview\"></td>
 				</tr>
 				<tr>" );
 			}

languages/messages/MessagesEn.php

@@ -1417,6 +1417,7 @@ If you have this image in full resolution upload this one, otherwise change the
 'license'            => 'Licensing',
 'nolicense'          => 'None selected',
 'licenses'           => '-', # don't translate or duplicate this message to other languages
+'license-nopreview' => '(Preview not available)',
 'upload_source_url'  => ' (a valid, publicly accessible URL)',
 'upload_source_file' => ' (a file on your computer)',
 

maintenance/language/messages.inc

@@ -827,6 +827,7 @@ $wgMessageStructure = array(
 		'license',
 		'nolicense',
 		'licenses',
+		'license-nopreview',
 		'upload_source_url',
 		'upload_source_file',
 	),

skins/common/upload.js

@@ -147,6 +147,7 @@ var wgUploadLicenceObj = {
 		if( licence in this.responseCache ) {
 			this.showPreview( this.responseCache[licence] );
 		} else {
+			injectSpinner( document.getElementById( 'wpLicense' ), 'licence' );
 			sajax_do_call( 'UploadForm::ajaxGetLicencePreview', [licence],
 				function( result ) {
 					wgUploadLicenceObj.processResult( result, licence );
@@ -156,17 +157,17 @@ var wgUploadLicenceObj = {
 	},
 
 	'processResult' : function( result, licence ) {
+		removeSpinner( 'licence' );
 		this.showPreview( result.responseText );
 		this.responseCache[licence] = result.responseText;
 	},
 
 	'showPreview' : function( preview ) {
 		var previewPanel = document.getElementById( 'mw-licence-preview' );
-		if( previewPanel.innerHTML != preview ) {
+		if( previewPanel.innerHTML != preview )
 			previewPanel.innerHTML = preview;
-		}
 	}
-
+	
 }
 
 addOnloadHook( licenseSelectorFixup );

skins/common/wikibits.js

@@ -1243,6 +1243,36 @@ function jsMsg( message, className ) {
 	return true;
 }
 
+/**
+ * Inject a cute little progress spinner after the specified element
+ *
+ * @param element Element to inject after
+ * @param id Identifier string (for use with removeSpinner(), below)
+ */
+function injectSpinner( element, id ) {
+	var spinner = document.createElement( "img" );
+	spinner.id = "mw-spinner-" + id;
+	spinner.src = stylepath + "/common/images/spinner.gif";
+	spinner.alt = spinner.title = "...";
+	if( element.nextSibling ) {
+		element.parentNode.insertBefore( spinner, element.nextSibling );
+	} else {
+		element.parentNode.appendChild( spinner );
+	}
+}
+
+/**
+ * Remove a progress spinner added with injectSpinner()
+ *
+ * @param id Identifier string
+ */
+function removeSpinner( id ) {
+	var spinner = document.getElementById( "mw-spinner-" + id );
+	if( spinner ) {
+		spinner.parentNode.removeChild( spinner );
+	}
+}
+
 function runOnloadHook() {
 	// don't run anything below this for non-dom browsers
 	if (doneOnloadHook || !(document.getElementById && document.getElementsByTagName)) {