* Fixed CreateDataset when TBufDataset.Filename is set

 * Clear old fielddefs before reading TBufDataset from file
 * Call bindfields while reading a dataset from file while there are 
   (calculated) fields present + test

git-svn-id: trunk@21756 -

packages/fcl-db/src/base/bufdataset.pas

@@ -2733,26 +2733,30 @@ begin
 end;
 
 procedure TCustomBufDataset.CreateDataset;
+var AStoreFilename: string;
+
 begin
   CheckInactive;
-  if not ((FieldCount=0) or (FieldDefs.Count=0)) then
+  if ((FieldCount=0) or (FieldDefs.Count=0)) then
     begin
-    Open;
-    Exit;
+    if (FieldDefs.Count>0) then
+      CreateFields
+    else if (fields.Count>0) then
+      begin
+      InitFieldDefsFromfields;
+      BindFields(True);
+      end
+    else
+      raise Exception.Create(SErrNoFieldsDefined);
     end;
-  if (FieldDefs.Count>0) then
-    begin
-    CreateFields;
-    Open;
-    end
-  else if (fields.Count>0) then
-    begin
-    InitFieldDefsFromfields;
-    BindFields(True);
+  // When a filename is set, do not read from this file
+  AStoreFilename:=FFileName;
+  FFileName := '';
+  try
     Open;
-    end
-  else
-    raise Exception.Create(SErrNoFieldsDefined);
+  finally
+    FFileName:=AStoreFilename;
+  end;
 end;
 
 function TCustomBufDataset.BookmarkValid(ABookmark: TBookmark): Boolean;
@@ -2772,8 +2776,12 @@ end;
 procedure TCustomBufDataset.IntLoadFielddefsFromFile;
 
 begin
+  FieldDefs.Clear;
   FDatasetReader.LoadFielddefs(FieldDefs);
-  if DefaultFields then CreateFields;
+  if DefaultFields then
+    CreateFields
+  else
+    BindFields(true);
 end;
 
 procedure TCustomBufDataset.IntLoadRecordsFromFile;

packages/fcl-db/tests/testbufdatasetstreams.pas

@@ -71,6 +71,7 @@ type
     procedure TestDeleteAllInsertXML;
     procedure TestStreamingBlobFieldsXML;
     procedure TestStreamingBigBlobFieldsXML;
+    procedure TestStreamingCalculatedFieldsXML;
 
     procedure TestAppendDeleteBIN;
 
@@ -543,6 +544,35 @@ begin
   end;
 end;
 
+procedure TTestBufDatasetStreams.TestStreamingCalculatedFieldsXML;
+var
+  ADataset: TCustomBufDataset;
+  f: tfield;
+begin
+  ADataset := DBConnector.GetNDataset(true,10) as TCustomBufDataset;
+  f := TIntegerField.Create(ADataset);
+  f.FieldName:='ID';
+  f.dataset := ADataset;
+
+  f := TIntegerField.Create(ADataset);
+  f.FieldName:='CalcID';
+  f.dataset := ADataset;
+  f.FieldKind:=fkCalculated;
+
+  f := TStringField.Create(ADataset);
+  f.FieldName:='NAME';
+  f.dataset := ADataset;
+
+  ADataset.Open;
+  ADataset.SaveToFile('FieldsDS.xml',dfXML);
+  ADataset.Close;
+
+  ADataset.LoadFromFile('FieldsDS.xml',dfXML);
+  AssertEquals(ADataset.FieldByName('ID').AsInteger,1);
+  AssertEquals(ADataset.FieldByName('NAME').AsString,'TestName1');
+  ADataset.Close;
+end;
+
 procedure TTestBufDatasetStreams.TestAppendDeleteBIN;
 begin
   TestChanges(@AppendDeleteChange);