fix(Message::appendText): QRegularExpression whitespace bug

[tux3]

Hello, sending a fix for a bug I ran into recently with Qt6 (https://phabricator.wikimedia.org/T383968)

It turns out that unlike QRegExp, when a QRegularExpression starts with \s, it may match whitespace including newlines.

So when looking for the start of a section, we might match "\n\n == January 2025 ==" instead of " == January 2025 =="

Then the logic that tries to skip past the header, would instead skip past the first \n, which is still before the header. Then we would think the target header is the start of the next section, and we would end up inserting a message just before the section it was intended to be appended to.

QRegularExpression is available since Qt 5.0 and is recommended. This gets rid of the old QRegExp and fixes the QRegularExpression usage in message.cpp (there's other uses of QRexExp/QRegularExpression elsewhere, but I haven't checked them for now)

Also includes some minor formatting changes. Let me know if I missed anything or if you'd like me to make some changes to the PR.

Cheers

[benapetr]

hello, thanks for the patch.

The only question I have - did you test it? Does it work? :)

P.S. The formatting is slightly different than rest of the code ({} brackets are horizontally aligned everywhere for easy visual recognition of start and end of a block, eg. old school Microsoft visual studio style), but that's somewhat irrelevant, I am willing to merge this either way.

[tux3]

The only question I have - did you test it? Does it work? :)

Yes, I've done a few manual tests and been test driving it today =)
I haven't committed a unit test, since I couldn't see a simple way to test this member function, so I've done some manual checks instead. It works with Qt5 and Qt6, and I've tried to Q&A the different edge cases manually (hopefully I didn't miss one!)

P.S. The formatting is slightly different than rest of the code ({} brackets are horizontally aligned everywhere for easy visual recognition of start and end of a block, eg. old school Microsoft visual studio style), but that's somewhat irrelevant, I am willing to merge this either way.

Ah, my bad! I searched to see which style was more prevalent and found both "} else {" and "} else\n{", so I wasn't sure. My IDE is also a big over-eager to reformat code automatically! ^^'
Will try to keep that in mind in the future =)