Standard double_quotes flag inconsistent value

[pmoura]

Consider the following queries:

Ciao 1.19.0 (2020-03-26 10:41:43 +0100) [DARWINx86_64]
?- set_prolog_flag(double_quotes, codes).

no
?- current_prolog_flag(double_quotes, codes).

no
?- current_prolog_flag(double_quotes, V).

V = chars ? ;

no
?- write("abc").
[97,98,99]
yes
?- set_prolog_flag(double_quotes, chars).

yes
?- write("abc").
[97,98,99]
yes
?- set_prolog_flag(double_quotes, atom).

no

It seems that the value of the double_quotes flag is wrongly reported as chars instead of codes. The flag is also not documented in the documentation on pre-defined flags.

[UWN]

@jfmc , as long as this is not fixed (and this cannot be very complex), further issues do not make much sense.

[jfmc]

Thanks @UWN, effectively there seems to be very few dependencies on this particular flag and we should be able to fix it quickly.