--- a/FileStream.st	Wed Mar 04 17:00:04 2020 +0100
+++ b/FileStream.st	Wed Mar 04 17:01:08 2020 +0100
@@ -759,13 +759,24 @@
     "return the access rights of the file as opaque data
      (SmallInteger in unix/linux)"
 
-    ^ OperatingSystem accessModeOfFd:self fileDescriptor.
+    |fd|
+
+    "self fileDescriptor sets handle to nil and
+     answers nil, if the handle is no longer valid!!"
+    fd := self fileDescriptor. 
+    fd isNil ifTrue:[
+        self errorNotOpen.
+        ^ nil.
+    ]. 
+    ^ OperatingSystem accessModeOfFd:fd.
 
     "
       'Make.proto' asFilename readingFileDo:[:s|
-	  s accessRights
+          s accessRights
       ]
     "
+
+    "Modified (comment): / 04-03-2020 / 13:11:30 / Stefan Vogel"
 !
 
 accessRights:opaqueData
@@ -773,23 +784,33 @@
      which is normally retrieved by Filename>>#accessRights
      or FileStreamm>>#accessRights."
 
-    (OperatingSystem changeAccessModeOfFd:self fileHandle to:opaqueData) ifFalse:[
-	OperatingSystem accessDeniedErrorSignal
-	    raiseRequestWith:self
-	    errorString:(' - cannot change access rights: ' , self pathName).
+    |fd|
+
+    fd := self fileHandle.
+    fd isNil ifTrue:[
+        self errorNotOpen.
+        ^ self.
+    ].    
+
+    (OperatingSystem changeAccessModeOfFd:fd to:opaqueData) ifFalse:[
+        OperatingSystem accessDeniedErrorSignal
+            raiseRequestWith:self
+            errorString:(' - cannot change access rights: ' , self pathName).
     ].
 
     "
       'Make.proto' asFilename readingFileDo:[:s|
-	  s accessRights:s accessRights
+          s accessRights:s accessRights
       ]
     "
 
     "
       '/' asFilename readingFileDo:[:s|
-	  s accessRights:s accessRights
+          s accessRights:s accessRights
       ]
     "
+
+    "Modified: / 04-03-2020 / 15:00:22 / Stefan Vogel"
 ! !
 
 !FileStream methodsFor:'accessing'!
@@ -919,11 +940,19 @@
      If nuberOfBytesOrNil is nil, copy until the end of myself.
      Redefined to use operating system features to do a fast copy."
 
-    |pos n nWritten|
+    |pos n nWritten fromFd toFd|
 
     outStream isExternalStream ifTrue:[
-        "sendfile() in Linux does not support any combination of file/pipe/socket fds.
-         #copyFromFd:toFd:startIndex:count: is currently not available in windows."
+        fromFd := self fileHandle.
+        fromFd isNil ifTrue:[
+            self errorNotOpen.
+            ^ self.
+        ].    
+        toFd := outStream fileHandle.
+        toFd isNil ifTrue:[
+            outStream errorNotOpen.
+            ^ self.
+        ].    
 
         pos := self position.
         numberOfBytesOrNil isNil ifTrue:[
@@ -931,9 +960,14 @@
         ] ifFalse:[
             n := numberOfBytesOrNil.
         ].
+        
+        "sendfile() in Linux does not support any combination of file/pipe/socket fds.
+         #copyFromFd:toFd:startIndex:count: is currently not available in windows.
+         Both will return 0 and fall through to super."
+
         nWritten := OperatingSystem
-                        copyFromFd:self fileHandle
-                        toFd:outStream fileHandle
+                        copyFromFd:fromFd
+                        toFd:toFd
                         startIndex:pos
                         count:n.
         nWritten > 0 ifTrue:[
@@ -963,6 +997,7 @@
 
     "Created: / 13-03-2019 / 16:27:04 / Stefan Vogel"
     "Modified (format): / 25-05-2019 / 16:47:53 / Claus Gittinger"
+    "Modified (comment): / 04-03-2020 / 15:09:52 / Stefan Vogel"
 !
 
 syncFileSystem