[Lazarus] Redundant assigned(X) and (X is Txxx) in Laz. sources

[Mattias Gaertner]

On Fri, 12 Jan 2018 21:44:47 +0200
Juha Manninen via Lazarus <lazarus at lists.lazarus-ide.org> wrote:

> On Fri, Jan 12, 2018 at 8:38 PM, Vojtěch Čihák via Lazarus
> <lazarus at lists.lazarus-ide.org> wrote:
> > I wrote a small routine to search Lazarus sources and it found about 60
> > places similar to this (taborderdlg.pas, line 398):
> >
> > if Assigned(LookupRoot) and (LookupRoot is TWinControl) then begin
> >
> > Should I make a patch for all occurences?  
> 
> Yes, I think the patch would be applied.
> IIRC "is" was not allowed with Nil references in old FPC versions but
> it was a long time ago.

No, "is" was always checking for nil.
Maybe some people are confused by "as", which does not check for nil.

Mattias