bug#36644: Git log search

[Juri Linkov]

>> > I also see your point: it would be nice to be able to document the
>> > semantics of PATTERN in a backend-independent way.  But I think this
>> > is next to impossible in this case, both because of significant
>> > differences in the backend capabilities (e.g., bzr doesn't have the
>> > equivalent of Git's --fixed-strings, AFAICT), and because some backend
>> > allow great flexibility in interpreting PATTERN, under control of
>> > optional switches passed to the backend.
>>
>> The other option is to standardize on basic or extended regexp, and
>> simply give up for backends that can't support that.
>
> We could simply say "regular expression" and leave the details
> unspecified.  But I think Juri said that fixed strings was the lowest
> common denominator, which is why I proposed a slightly more vague doc
> string.  Juri, which backends don't support regular expressions?

The documentation of 'git-log' uses the term 'pattern' for a good reason
since it covers all possible values: basic-regexp, extended-regexp,
perl-regexp, fixed-strings.