[Lazarus] ComboBox bug?

[Mattias Gaertner]

On Fri, 23 Sep 2011 22:24:15 +0200
Hans-Peter Diettrich <DrDiettrich1 at aol.com> wrote:

> Mattias Gaertner schrieb:
> > On Fri, 23 Sep 2011 16:23:02 +0200
> > Hans-Peter Diettrich <DrDiettrich1 at aol.com> wrote:
> > 
> >> Mattias Gaertner schrieb:
> >>> Hans-Peter Diettrich <DrDiettrich1 at aol.com> hat am 23. September 2011 um 
> >>> 05:40 geschrieben:
> >>>
> >>>  > Mattias Gaertner schrieb:
> >>>  >
> >>>  > > procedure TCustomComboBox.UpdateSorted;
> >>>  > > var
> >>>  > >   lText: string;
> >>>  > >   lIndex: integer;
> >>>  > > begin
> >>>  > >   if HandleAllocated then
> >>>  > >     TWSCustomComboBoxClass(WidgetSetClass).Sort(Self, Items, FSorted)
> >>>  > >   else if FItems is TStringList then
> >>>  > >   begin
> >>>  > >     // remember text
> >>>  > >     lText := Text;
> >>>  > >     TStringList(FItems).Sorted := FSorted;
> >>>  > >
> >>>  > > When not FSorted then items are not sorted.
> >>>  >
> >>>  > You're right.
> >>>  >
> >>>  > But the following then is also evitable (but does no harm):
> >>>  >
> >>>  > >     lIndex := FItems.IndexOf(lText);
> >>>  > >     if lIndex >= 0 then
> >>>  > >       ItemIndex := lIndex;
> >>>  >
> >>>  > What if lIndex=-1?
> >>>
> >>>  
> >>>
> >>> Nothing.
> >> Obviously - but why?
> > 
> > What else do you expect to happen?
> 
> I wonder e.g. why ItemIndex is not tested before all further processing. 
> When nothing has been selected before sorting, then after sorting 
> nothing should be/become selected as well.

ItemIndex -1 means the text does not exist in the list.


Mattias