OO-1970 fix nullpointer for non existing company logo

src/main/java/org/olat/user/HomePageDisplayController.java

@@ -125,10 +125,12 @@ public class HomePageDisplayController extends BasicController {
 
 		if(UserModule.isLogoByProfileEnabled()) {
 			File logo = DisplayPortraitManager.getInstance().getBigLogo(homeIdentity.getName());
-			ImageComponent logoCmp = new ImageComponent(ureq.getUserSession(), "logo");
-			logoCmp.setMedia(logo);
-			logoCmp.setMaxWithAndHeightToFitWithin(300, 66);
-			mainVC.put("logo", logoCmp);
+			if (logo != null) {
+				ImageComponent logoCmp = new ImageComponent(ureq.getUserSession(), "logo");
+				logoCmp.setMedia(logo);
+				logoCmp.setMaxWithAndHeightToFitWithin(300, 66);
+				mainVC.put("logo", logoCmp);				
+			}
 		}
 		
 		putInitialPanel(mainVC);

src/main/resources/serviceconfig/olat.properties

@@ -674,6 +674,8 @@ userinfos.tunnelcoursebuildingblock=disabled
 userDisplayName=userDisplayName_lastname_firstname
 userDisplayName.values=userDisplayName_firstname_lastname, userDisplayName_lastname_firstname
 
+# An additional image attached to the user profile, eg. for the company logo. 
+# Diplayed on the users vising card
 user.logoByProfile=disabled
 user.logoByProfile.values=enabled,disabled