Replace non-ASCII characters in recording filenames.

[softins]

Replaces high-order Latin characters with their nearest ASCII equivalent for readability.
Other non-ASCII chars are replaced with '_'.

Fixes #1424

[hoffie]

Getting this with gcc 10.2.0:

src/recorder/jamrecorder.cpp: In member function 'QString recorder::CJamClient::TranslateChars(const QString&) const':
src/recorder/jamrecorder.cpp:125:16: warning: comparison is always false due to limited range of data type [-Wtype-limits]
  125 |         c = (c >= 128) ? charmap[c - 128] : (c >= 32) ? c : '_';
      |              ~~^~~~~~

In fact, German 'Ä' is replaced by '_' but I guess it was supposed to be replaced by 'A' in your logic?

[softins]

Ok, this must be a portability thing. On your system auto &c must be getting typed as signed char, whereas on mine it gets typed as unsigned char. That would be why on your system it never uses the array.

I could try it with unsigned char &c instead, but that might end up as a type mismatch. Or maybe just cast c to unsigned within the loop body.

No time on Sat to look at it, will do Sun or Mon. I see the Mac build failed too, so will have to see why.

[softins]

I’ve pushed a change that hopefully might be portable. Let’s see.

[hoffie]

No more warnings for me and Ä is proplery replaced with A. Looks good.

[pljones]

If this is going to be done, it might as well remove all the nasties, rather than adding some -- specifically the ones that then get replaced: -, ., :, /, \, (space). However, it's best to avoid ,, ~, %, |, ^, <, >, ', and ", really, as they're difficult on certain platforms (I should probably have stripped them, too).

[hoffie]

Should probably be squash-merged?

[softins]

If this is going to be done, it might as well remove all the nasties, rather than adding some -- specifically the ones that then get replaced: -, ., :, /, \, (space). However, it's best to avoid ,, ~, %, |, ^, <, >, ', and ", really, as they're difficult on certain platforms (I should probably have stripped them, too).

Well the function of TranslateChars() is to replace high-order Latin1 characters with their nearest ASCII equivalents, if any, not to sanitise for platform filename conventions. That is the job of the Regex replace further down the expression that constructs the filename. Bear in mind TranslateChars() doesn't do anything to characters that are already ASCII.

[softins]

Unless you would prefer that TranslateChars() had a complete 256-byte table and also took over the job of sanitising, instead of the .replace(QRegExp? @pljones

[pljones]

Unless you would prefer that TranslateChars() had a complete 256-byte table and also took over the job of sanitising, instead of the .replace(QRegExp? @pljones

If it's only going to be used in the one place, it might as well do it -- it'll be cheaper than the QRegExp, too, I expect. Yeah...