--- a/UserPreferences.st	Tue May 28 16:19:05 2019 +0200
+++ b/UserPreferences.st	Tue May 28 17:44:04 2019 +0200
@@ -1384,14 +1384,14 @@
     "the external command to use for diff"
 
     ^ self
-	at:#externalDiffCommandTemplate
-	ifAbsent:[
-	    OperatingSystem isMSDOSlike ifTrue:[
-		'diff %1 %2'
-	    ] ifFalse:[
-		'diff -b %1 %2'
-	    ]
-	]
+        at:#externalDiffCommandTemplate
+        ifAbsent:[
+            OperatingSystem isMSDOSlike ifTrue:[
+                'diff "%1" "%2"'
+            ] ifFalse:[
+                'diff -b "%1" "%2"'
+            ]
+        ]
 
     "
      UserPreferences current externalDiffCommandTemplate
@@ -1399,6 +1399,7 @@
 
     "Modified: / 13-10-1998 / 15:53:05 / cg"
     "Created: / 26-07-2012 / 15:06:31 / cg"
+    "Modified: / 28-05-2019 / 17:31:55 / Stefan Reise"
 !
 
 externalDiffCommandTemplate:aString