Fallback to PCRE2 if match whole word used with regexp

[IllusionMH]

Fixes #82071

This PR ensures that --auto-hybrid-regex will be added to Regexp searches regardless of Match Whole Word state.

Changed order of operations a bit to keep related checks and CLI arguments nearby.

[roblourens]

Thanks for the PR! But if it is a non-regex whole word search, it won't be added, right? Maybe it should just be duplicated and put next to the --regexp switch to make sure it always gets set for regex searches

[IllusionMH]

But if it is a non-regex whole word search, it won't be added, right?

Correct. If isWordMatch is true but isRegExp is false - it won't be added [1].

Maybe it should just be duplicated and put next to the --regexp switch to make sure it always gets set for regex searches

That was my first intention, but if it is added unconditionally then it will be also applied to all non-regex whole word searches. If condition added - that there will be 2 similar conditions which looks confusing as for me. Therefore I moved args.push('--auto-hybrid-regex'); in check right above blocks where ---regexp will be added.

Example with duplicate + condition.

if (query.isWordMatch) {
	const regexp = createRegExp(query.pattern, !!query.isRegExp, { wholeWord: query.isWordMatch });
	const regexpStr = regexp.source.replace(/\\\//g, '/'); // RegExp.source arbitrarily returns escaped slashes. Search and destroy.
	args.push('--regexp', regexpStr);
	if (query.isRegExp) { // same as below
		args.push('--auto-hybrid-regex');
	}
} else if (query.isRegExp) { // same as above
	let fixedRegexpQuery = fixRegexNewline(query.pattern);
	fixedRegexpQuery = fixNewline(fixedRegexpQuery);
	args.push('--regexp', fixedRegexpQuery);
	args.push('--auto-hybrid-regex');
}

---

[1] only exception is special case when search query is exactly --. In this case isRegExp will be overridden to true, and --auto-hybrid-regex will be added even if user doesn't use regexp search.

[roblourens]

then it will be also applied to all non-regex whole word searches

But we convert all whole word searches to regex searches, even if they are not originally regex searches, that is my point.

[IllusionMH]

Yes.
It was my assumption that adding --auto-hybrid-regex for cases when it won't be used is undesirable (I would expect that whole word search should always be valid input for non-PCRE2 implementation).

I'll happily update PR to simply duplicate line if it's OK to always include it.

[roblourens]

I would expect that whole word search should always be valid input for non-PCRE2 implementation

Ok, that's a good point.

[IllusionMH]

Yes, so it's just about preference. I don't think that it has any performance impact in any of two options (this PR or include for every regexp search).

Thanks for reviewing!