Merge branch 'patch/JAL-4298_synchronize_consoledoc' into bug/JAL-4298_java_console_c...

diff --cc src/jalview/gui/Console.java
index 631e0a2,9fe7195..7e8cbc6
--- 1/src/jalview/gui/Console.java
--- 2/src/jalview/gui/Console.java
+++ b/src/jalview/gui/Console.java
@@@ -713,12 -683,16 +713,16 @@@ public class Console extends WindowAdap
                displayPipe = tmp;
              }
              // simply append whole buffer
-             textArea.append(replace.toString()); // ##### implicated BLOCKED
-             count += replace.length();
-             if (count > byteslim)
+             synchronized (textArea.getDocument())
              {
-               trimBuffer(false);
+               textArea.append(replace.toString());
+               count += replace.length();
+               if (count > byteslim)
+               {
+                 trimBuffer(false);
+               }
              }
 -            
++
            }
            if (displayPipe.length() == 0)
            {