# HG changeset patch
# User wenzelm
# Date 1473854829 -7200
# Node ID 22037a819276f9f3ab22e716cffde614e7f723b2
# Parent  fb46c031c8416e79136c756355c751afbc4c58ce
more robust;

diff -r fb46c031c841 -r 22037a819276 src/Tools/jEdit/src/isabelle.scala
--- a/src/Tools/jEdit/src/isabelle.scala	Wed Sep 14 12:56:57 2016 +0200
+++ b/src/Tools/jEdit/src/isabelle.scala	Wed Sep 14 14:07:09 2016 +0200
@@ -61,11 +61,13 @@
     }
 
   def buffer_syntax(buffer: JEditBuffer): Option[Outer_Syntax] =
-    (JEdit_Lib.buffer_mode(buffer), PIDE.document_model(buffer)) match {
-      case ("isabelle", Some(model)) =>
-        Some(PIDE.session.recent_syntax(model.node_name))
-      case (mode, _) => mode_syntax(mode)
-    }
+    if (buffer == null) None
+    else
+      (JEdit_Lib.buffer_mode(buffer), PIDE.document_model(buffer)) match {
+        case ("isabelle", Some(model)) =>
+          Some(PIDE.session.recent_syntax(model.node_name))
+        case (mode, _) => mode_syntax(mode)
+      }
 
 
   /* token markers */