bug#28439: suggestion: support case-independent

[Dmitry Gutov <dgutov@yandex.ru>]

On 9/15/17 1:32 AM, Winston wrote:

> OK, but if it's a couple years from now before it happens, I'm likely to
> assume you're not still interested.  :)

I probably would. :)

>>> * xref-completion-ignore-case, default t;
> 
>>> * creating something that applies to both completions and
>>>     find-definition (I didn't save the patch, but my vague
>>>     recollection is that it just defaulted to using t for
>>>     completions).
> 
>> Not sure what this means, need details.
> 
> The first was a variable that only affects completions.
> 
> The second controls both completions and what xref-find-definitions
> matches, so either both would allow case folding or both would not.

The second option is something to consider indeed. Since we don't 
require a match during completion, the user can enter a string that 
would have completions, but gets no case-sensitive matches.

We can do that without an extra variable, though, by making definitions 
search be controlled by completion-ignore-case.