* adjust handling of empty buffer as a valid reference is needed nevertheless

git-svn-id: trunk@37074 -

packages/rtl-objpas/src/inc/rtti.pp

@@ -445,6 +445,8 @@ end;
 
 procedure IntFinalize(APointer, ATypeInfo: Pointer);
   external name 'FPC_FINALIZE';
+procedure IntInitialize(APointer, ATypeInfo: Pointer);
+  external name 'FPC_INITIALIZE';
 procedure IntAddRef(APointer, ATypeInfo: Pointer);
   external name 'FPC_ADDREF';
 function IntCopy(ASource, ADest, ATypeInfo: Pointer): SizeInt;
@@ -457,22 +459,32 @@ begin
   if ALen>0 then
     begin
       Getmem(FBuffer,FDataSize);
-      system.move(ACopyFromBuffer^,FBuffer^,FDataSize);
+      if Assigned(ACopyFromBuffer) then
+        system.move(ACopyFromBuffer^,FBuffer^,FDataSize)
+      else
+        FillChar(FBuffer^, FDataSize, 0);
     end;
   FIsCopy := True;
   FUseAddRef := AAddRef;
-  if AAddRef and (ALen > 0) then
-    IntAddRef(FBuffer, FTypeInfo);
+  if AAddRef and (ALen > 0) then begin
+    if Assigned(ACopyFromBuffer) then
+      IntAddRef(FBuffer, FTypeInfo)
+    else
+      IntInitialize(FBuffer, FTypeInfo);
+  end;
 end;
 
 constructor TValueDataIntImpl.CreateRef(AData: Pointer; ATypeInfo: PTypeInfo; AAddRef: Boolean);
 begin
   FTypeInfo := ATypeInfo;
   FDataSize := SizeOf(Pointer);
-  FBuffer := PPointer(AData)^;
+  if Assigned(AData) then
+    FBuffer := PPointer(AData)^
+  else
+    FBuffer := Nil;
   FIsCopy := False;
   FUseAddRef := AAddRef;
-  if AAddRef then
+  if AAddRef and Assigned(AData) then
     IntAddRef(@FBuffer, FTypeInfo);
 end;
 
@@ -565,10 +577,17 @@ begin
 {$else}
   Result.FData.FAsUInt64 := 0;
 {$endif}
-  if not Assigned(ABuffer) or not Assigned(ATypeInfo) then
+  if not Assigned(ATypeInfo) then
     Exit;
+  { first handle those types that need a TValueData implementation }
   case ATypeInfo^.Kind of
-    tkSString  : result.FData.FValueData := TValueDataIntImpl.CreateCopy(ABuffer, Length(PShortString(ABuffer)^) + 1, ATypeInfo, True);
+    tkSString  : begin
+                   if Assigned(ABuffer) then
+                     size := Length(PShortString(ABuffer)^) + 1
+                   else
+                     size := 256;
+                   result.FData.FValueData := TValueDataIntImpl.CreateCopy(ABuffer, size, ATypeInfo, True);
+                 end;
     tkWString,
     tkUString,
     tkAString  : result.FData.FValueData := TValueDataIntImpl.CreateRef(ABuffer, ATypeInfo, True);
@@ -576,10 +595,26 @@ begin
     tkArray    : result.FData.FValueData := TValueDataIntImpl.CreateCopy(ABuffer, Result.TypeData^.ArrayData.Size, ATypeInfo, False);
     tkObject,
     tkRecord   : result.FData.FValueData := TValueDataIntImpl.CreateCopy(ABuffer, Result.TypeData^.RecSize, ATypeInfo, False);
+    tkInterface: result.FData.FValueData := TValueDataIntImpl.CreateRef(ABuffer, ATypeInfo, True);
+  end;
+  if not Assigned(ABuffer) then
+    Exit;
+  { now handle those that are happy with the variant part of FData }
+  case ATypeInfo^.Kind of
+    tkSString,
+    tkWString,
+    tkUString,
+    tkAString,
+    tkDynArray,
+    tkArray,
+    tkObject,
+    tkRecord,
+    tkInterface:
+      { ignore }
+      ;
     tkClass    : result.FData.FAsObject := PPointer(ABuffer)^;
     tkClassRef : result.FData.FAsClass := PClass(ABuffer)^;
     tkInterfaceRaw : result.FData.FAsPointer := PPointer(ABuffer)^;
-    tkInterface: result.FData.FValueData := TValueDataIntImpl.CreateRef(ABuffer, ATypeInfo, True);
     tkInt64    : result.FData.FAsSInt64 := PInt64(ABuffer)^;
     tkQWord    : result.FData.FAsUInt64 := PQWord(ABuffer)^;
     tkProcVar  : result.FData.FAsMethod.Code := PCodePointer(ABuffer)^;