bug#37820: 25.2; xref using etags incorrect case fold during completion

[Radey Shouman]

Dmitry Gutov writes:
>On 19.10.2019 20:34, Radey Shouman wrote:
>> I found it surprising that completion would not follow the tags search
>> itself in folding case, as I have become used to this useful behavior
>> over many years of using find-tag.

>You are not calling a tags search command, though. You are calling a
>backend-agnostic command. Maybe there are inconsistencies there, but I
>think they should be resolved in favor of general variables.

>In any case, is there a particular reason you customize these vars like
>that?

Please copy me on any messages to which you expect a response.
I have not subscribed to the mailing list.

The only variable I customize is tags-case-fold-search, I leave
completion-ignore-case with the default value.  I heartily regret
even mentioning the latter variable, it is a red herring.

There are at least two reasons to change tags-case-fold-search:

1) Some programming languages are not case sensitive in normal use,
eg Common Lisp, Fortran, Cobol, R[45]RS Scheme ...  For these languages
case-insensitive search should be the default.

2) For many code bases the rules of CamelCasing are so vague, or their
observance so lax, that it's hard to predict what the capitalization
of an identifier will be.  It's useful in these cases to use
completion that is not case sensitive.