--- a/XWorkstation.st	Mon Feb 03 11:30:41 2014 +0100
+++ b/XWorkstation.st	Mon Feb 03 11:33:05 2014 +0100
@@ -29,7 +29,8 @@
 		stxDeviceAtom uuidAtom primaryBuffer windowGroupWindow
 		maxOperationsUntilFlush operationsUntilFlush'
 	classVariableNames:'RawKeySymTranslation ConservativeSync MaxStringLength
-		DefaultXLibTimeout DefaultXLibTimeoutForWindowCreation'
+		DefaultXLibTimeout DefaultXLibTimeoutForWindowCreation
+		ErrorDBCache'
 	poolDictionaries:''
 	category:'Interface-Graphics'
 !
@@ -614,25 +615,41 @@
      when buffering is on, this may be
      an error for a long-ago operation"
 
-    |string s match line|
+    |string s match line requestCode|
 
     string := self errorStringOfLastError.
+    requestCode := self requestCodeOfLastError.
+
     "
      X specific: search the requestCode in '/usr/lib/X11/XErrorDB',
      and append the name of the corresponding X-request
     "
-    match := 'XRequest.' , self requestCodeOfLastError printString.
-    s := '/usr/lib/X11/XErrorDB' asFilename readStreamOrNil.
-    s notNil ifTrue:[
-        line := s peekForLineStartingWith:match.
-        s close.
-    ].
+    match := 'XRequest.' , requestCode printString.
+    ErrorDBCache isNil ifTrue:[
+        ErrorDBCache := IdentityDictionary new.
+    ].
+
+    "if there is no XErrorDB or no entry, the line for the requestCode is cached as nil"    
+    line := ErrorDBCache at:requestCode ifAbsentPut:[
+            |errorLine|
+
+            s := '/usr/share/X11/XErrorDB' asFilename readStreamOrNil.
+            s notNil ifTrue:[
+                errorLine := s peekForLineStartingWith:match.
+                errorLine := errorLine copyFrom:(errorLine indexOf:$:)+1.
+                s close.
+            ].
+            errorLine
+        ].
+
     line isNil ifTrue:[
-        string := string, ' in ', match
-    ] ifFalse:[
-        string := string , ' in ' , (line copyFrom:(line indexOf:$:)+1)
-    ].
-    ^ string
+        line := match
+    ].
+    ^ string , ' in ' , line.
+
+    "
+        Screen lastErrorString
+    "
 !
 
 minorCodeOfLastError
@@ -13027,11 +13044,11 @@
 !XWorkstation class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libview/XWorkstation.st,v 1.579 2013-12-20 10:03:12 vrany Exp $'
+    ^ '$Header: /cvs/stx/stx/libview/XWorkstation.st,v 1.580 2014-02-03 10:33:05 stefan Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libview/XWorkstation.st,v 1.579 2013-12-20 10:03:12 vrany Exp $'
+    ^ '$Header: /cvs/stx/stx/libview/XWorkstation.st,v 1.580 2014-02-03 10:33:05 stefan Exp $'
 !
 
 version_SVN