Hi,

In FPC 3.2.0 the default "Default" value of a single/double property has changed from $80000000 (fpc 3.0.4) to 0.

This breaks TWriter.
The $80000000 means the property has no default value. Now FPC 3.2.0 no longer writes a property if the value is 0.0, no matter what the stored function says.

For example:
property S: Single read FSingle write FSingle stored IsSStored;

FPC 3.0.4 TWriter does write S if S=0.0 and IsSStored returns true. FPC 3.2.0 does not.

I can't find this change in
https://wiki.lazarus.freepascal.org/User_Changes_3.2.0

Mattias

Maybe this is related to bugs 33564 & 31985 ?

It was indeed the fix for Mantis #31985 (
https://bugs.freepascal.org/view.php?id=31985 ) that changed this and the behavior of the RTTI is Delphi-compatible now. If you want the default value to be $80000000 again you need to append "nodefault" to the property.

I can't find this change in https://wiki.lazarus.freepascal.org/User_Changes_3.2.0

@Ondrej: you had supplied the patch back then. Would you be able to describe what exactly changed through your patch?

Regards,
Sven

I added a point to
https://wiki.lazarus.freepascal.org/User_Changes_3.2.0#RTTI_changes

Ondrej

I forgot to add a short personal rant :)

The ambiguity of the /stored/ and /(no)default/ modifiers is a huge source of confusion and errors. Such a bad design :/ (Obviously FPC is not liable for it.)

Having only the "stored" modifier would be so much simpler. (And you would be able to store all integer values in a property - currently you always have to choose one value that is not stored.)

Ondrej

Ondrej Pokorny schrieb am Sa., 6. März 2021, 04:29:

Thank you! :)

Regards,
Sven