'Invalid variant type'. finalizatron error

dcoun · 2026-06-09 09:52:31

After commit e6bf459b17a676bd052d09ccab21ea76413cb876 I am getting record finalization error with the following stack:
Project pc.exe raised exception class EVariantBadVarTypeError with message 'Invalid variant type'.
https://gist.github.com/dkounal/99361a1 … bb4296bfa2

ab · 2026-06-09 19:30:37

Is it still the case?

It sounds like if the variant is identified as a varArray, which should not be possible with pure mORMot code.
We would need some minimum reproducible example, please.

dcoun · 2026-06-11 08:49:01

please change in mormot.core.rtti.pas line 6877 to the following:

    if (ElemInfo <> nil) and
       (p^.length > 0) then 
          FastFinalizeArray(Value^, ElemInfo, p^.length);

It seems to work ok with the above

ab · 2026-06-11 13:17:04

It is really unexpected to have p^.Length = 0 here.
A void dynamic array is expected to be stored as a nil pointer, not something with Length=0 in its headers.
I suspect there is something wrong elsewhere.

At least I have hardened FastFinalizeArray() usage:
https://github.com/synopse/mORMot2/commit/aad4c731a

dcoun · 2026-06-12 15:39:48

I can send you a unit that produced this error to check it and tell me. But it happens in my code when an empty json result is returned with just the fields.
thank you a lot for the fix

ab · 2026-06-12 19:21:37

How does "an empty json result is returned with just the fields" look like?
For which type associated with RTTI?

mORMot Open Source

#1 2026-06-09 09:52:31

'Invalid variant type'. finalizatron error

#2 2026-06-09 19:30:37

Re: 'Invalid variant type'. finalizatron error

#3 2026-06-11 08:49:01

Re: 'Invalid variant type'. finalizatron error

#4 2026-06-11 13:17:04

Re: 'Invalid variant type'. finalizatron error

#5 2026-06-12 15:39:48

Re: 'Invalid variant type'. finalizatron error

#6 2026-06-12 19:21:37

Re: 'Invalid variant type'. finalizatron error

Board footer