--- a/ExternalLibraryFunction.st	Thu Feb 22 17:07:47 2018 +0100
+++ b/ExternalLibraryFunction.st	Sat Feb 24 13:13:46 2018 +0100
@@ -605,43 +605,43 @@
     "let this execute in a separate thread, in par with the other execution thread(s).
      Ignored under unix/linux (until those support multiple threads too)."
 
-    flags := (flags ? 0) bitOr: FLAG_ASYNC.
+    flags := flags bitOr: FLAG_ASYNC.
 
     "Created: / 01-08-2006 / 13:42:38 / cg"
 !
 
 beCallTypeAPI
-    flags := (flags ? 0) bitOr: CALLTYPE_API.
+    flags := flags bitOr: CALLTYPE_API.
 
     "Created: / 01-08-2006 / 15:12:40 / cg"
 !
 
 beCallTypeC
-    flags := (flags ? 0) bitOr: CALLTYPE_C.
+    flags := flags bitOr: CALLTYPE_C.
 
     "Created: / 01-08-2006 / 15:12:40 / cg"
 !
 
 beCallTypeOLE
-    flags := (flags ? 0) bitOr: FLAG_VIRTUAL.
+    flags := flags bitOr: FLAG_VIRTUAL.
 
     "Created: / 01-08-2006 / 15:12:40 / cg"
 !
 
 beCallTypeUNIX64
-    flags := (flags ? 0) bitOr: CALLTYPE_UNIX64.
+    flags := flags bitOr: CALLTYPE_UNIX64.
 
     "Created: / 01-08-2006 / 15:13:38 / cg"
 !
 
 beCallTypeV8
-    flags := (flags ? 0) bitOr: CALLTYPE_V8.
+    flags := flags bitOr: CALLTYPE_V8.
 
     "Created: / 01-08-2006 / 15:13:28 / cg"
 !
 
 beCallTypeV9
-    flags := (flags ? 0) bitOr: CALLTYPE_V9.
+    flags := flags bitOr: CALLTYPE_V9.
 
     "Created: / 01-08-2006 / 15:13:31 / cg"
 !
@@ -656,7 +656,7 @@
     "specify that a pointer return value is not to be finalized
      (i.e. points to static data or data which is freed by c)"
 
-    flags := (flags ? 0) bitOr: FLAG_RETVAL_IS_CONST.
+    flags := flags bitOr: FLAG_RETVAL_IS_CONST.
 
     "Created: / 01-08-2006 / 13:56:48 / cg"
 !
@@ -665,7 +665,7 @@
     "specify that a pointer return value is to be freed explicitly by st/x
      (i.e. points to mallocd data which is not freed by c)"
 
-    flags := (flags ? 0) bitOr: FLAG_RETVAL_MUST_FREE.
+    flags := flags bitOr: FLAG_RETVAL_MUST_FREE.
 
     "Created: / 12-02-2017 / 23:41:48 / cg"
 !
@@ -673,7 +673,7 @@
 beNonVirtualCPP
     "specify this as a non-virtual c++-function"
 
-    flags := (flags ? 0) bitOr: FLAG_NONVIRTUAL.
+    flags := flags bitOr: FLAG_NONVIRTUAL.
 
     "Created: / 01-08-2006 / 13:56:44 / cg"
 !
@@ -681,7 +681,7 @@
 beObjectiveC
     "specify this as an objective-c message send"
 
-    flags := (flags ? 0) bitOr: FLAG_OBJECTIVEC.
+    flags := flags bitOr: FLAG_OBJECTIVEC.
 
     "Created: / 01-08-2006 / 13:56:48 / cg"
 !
@@ -691,7 +691,7 @@
      for unlimited auto-sized-stack under unix/linux.
      Ignored under windows."
 
-    flags := (flags ? 0) bitOr: FLAG_UNLIMITEDSTACK.
+    flags := flags bitOr: FLAG_UNLIMITEDSTACK.
 
     "Created: / 01-08-2006 / 13:41:54 / cg"
 !
@@ -699,13 +699,13 @@
 beVirtualCPP
     "specify this as a virtual c++-function"
 
-    flags := (flags ? 0) bitOr: FLAG_VIRTUAL.
+    flags := flags bitOr: FLAG_VIRTUAL.
 
     "Created: / 01-08-2006 / 13:56:48 / cg"
 !
 
 callTypeNumber
-    ^ (flags ? 0) bitAnd: CALLTYPE_MASK.
+    ^ flags bitAnd: CALLTYPE_MASK.
 
     "Created: / 01-08-2006 / 15:12:10 / cg"
 !
@@ -713,7 +713,7 @@
 isAsync
     "is this executed in a separate thread, in par with the other execution thread(s) ?"
 
-    ^ (flags ? 0) bitTest: FLAG_ASYNC.
+    ^ flags bitTest: FLAG_ASYNC.
 
     "Created: / 01-08-2006 / 13:46:53 / cg"
 !
@@ -721,7 +721,7 @@
 isCPPFunction
     "is this a virtual or non-virtual c++-function ?"
 
-    ^ (flags ? 0) bitTest: (FLAG_VIRTUAL bitOr: FLAG_NONVIRTUAL).
+    ^ flags bitTest: (FLAG_VIRTUAL bitOr: FLAG_NONVIRTUAL).
 
     "Created: / 01-08-2006 / 13:56:54 / cg"
 !
@@ -732,7 +732,7 @@
      and MUST be declared as such for many Kernel functions.
      The calltype API is one of the worst historic garbage kept by MS..."
 
-    ^ ((flags ? 0) bitAnd: CALLTYPE_MASK) == CALLTYPE_API.
+    ^ (flags bitAnd: CALLTYPE_MASK) == CALLTYPE_API.
 
     "Created: / 01-08-2006 / 15:21:16 / cg"
 !
@@ -740,7 +740,7 @@
 isCallTypeC
     "is this a regular C-call (attention: on windows, there are two kinds of calls)"
 
-    ^ ((flags ? 0) bitAnd: CALLTYPE_MASK) == CALLTYPE_C.
+    ^ (flags bitAnd: CALLTYPE_MASK) == CALLTYPE_C.
 
     "Created: / 01-08-2006 / 15:21:23 / cg"
 !
@@ -748,7 +748,7 @@
 isCallTypeOLE
     "is this an OLE-object call ? (eg. a virtual c++ call; same as isCallTypeCPP)"
 
-    ^ (flags ? 0) bitTest: FLAG_VIRTUAL.
+    ^ flags bitTest: FLAG_VIRTUAL.
 
     "Created: / 01-08-2006 / 15:21:23 / cg"
     "Modified (format): / 12-11-2016 / 11:37:38 / cg"
@@ -758,7 +758,7 @@
     "is the pointer return value not to be finalized
      (i.e. points to static data or data which is freed by c)"
 
-    ^ (flags ? 0) bitTest: FLAG_RETVAL_IS_CONST.
+    ^ flags bitTest: FLAG_RETVAL_IS_CONST.
 
     "Created: / 01-08-2006 / 13:56:48 / cg"
 !
@@ -766,7 +766,7 @@
 isNonVirtualCPP
     "is this a non-virtual c++-function ?"
 
-    ^ (flags ? 0) bitTest: FLAG_NONVIRTUAL.
+    ^ flags bitTest: FLAG_NONVIRTUAL.
 
     "Created: / 01-08-2006 / 13:56:51 / cg"
 !
@@ -774,7 +774,7 @@
 isObjectiveC
     "is this an objective-C message?"
 
-    ^ (flags ? 0) bitTest: FLAG_OBJECTIVEC.
+    ^ flags bitTest: FLAG_OBJECTIVEC.
 !
 
 isUnlimitedStack
@@ -782,7 +782,7 @@
      for unlimited auto-sized-stack under unix/linux.
      Ignored under windows."
 
-    ^ (flags ? 0) bitTest: FLAG_UNLIMITEDSTACK.
+    ^ flags bitTest: FLAG_UNLIMITEDSTACK.
 
     "Created: / 01-08-2006 / 14:17:07 / cg"
 !
@@ -790,7 +790,7 @@
 isVirtualCPP
     "is this a virtual c++-function (same as isCallTypeOLE) ?"
 
-    ^ (flags ? 0) bitTest: FLAG_VIRTUAL.
+    ^ flags bitTest: FLAG_VIRTUAL.
 
     "Created: / 01-08-2006 / 13:56:54 / cg"
 !
@@ -800,10 +800,10 @@
 !
 
 mustFreeReturnValue
-    "specify that a pointer to some C-datum is returned, which must be freed by ST/X.
+    "answer true, if a pointer to some C-datum is returned, which must be freed by ST/X.
      (i.e. points to malloc'd data which is NOT freed by c)"
 
-    flags := (flags ? 0) bitOr: FLAG_RETVAL_MUST_FREE.
+    ^ flags bitTest: FLAG_RETVAL_MUST_FREE.
 
     "Created: / 12-02-2017 / 23:31:27 / cg"
 !
@@ -919,7 +919,7 @@
             self isCallTypeC ifTrue:[
                 'C:' printOn:aStream.
             ] ifFalse:[
-                self error.
+                aStream nextPutAll:'Error: unknown call type '.
             ].
         ].
     ].
@@ -1109,9 +1109,10 @@
 !ExternalLibraryFunction methodsFor:'private-accessing'!
 
 name:functionNameOrVirtualIndex module:aModuleName returnType:aReturnType argumentTypes:argTypes
+    flags := 0.    
     name := functionNameOrVirtualIndex.
     functionNameOrVirtualIndex isNumber ifTrue:[
-	self beVirtualCPP.
+        self beVirtualCPP.
     ].
     moduleName := aModuleName.
     returnType := aReturnType.
@@ -2685,13 +2686,13 @@
         returnValue = __MKEXTERNALBYTES(__returnValue.pointerVal);
     } else if (returnTypeSymbol == @symbol(charPointer)) {
         returnValue = __MKSTRING(__returnValue.pointerVal);
-        if (mustFreeRetVal) {
+        if (mustFreeRetVal == true) {
             free(__returnValue.pointerVal);
             alreadyFreed = true;
         }
     } else if (returnTypeSymbol == @symbol(wcharPointer)) {
         returnValue = __MKU16STRING(__returnValue.pointerVal);
-        if (mustFreeRetVal) {
+        if (mustFreeRetVal == true) {
             free(__returnValue.pointerVal);
             alreadyFreed = true;
         }