Virgo Pärna wrote on 6/16/20 6:27 AM: > > Nothing to do with keyboard layouts. Some fonts have ligatures, > that combine two different characters into one symbol. I actually tried > it on Windows with Thunderbird and "Cascadia Mono" font. Rendering > engine in Thunderbird probably has ligature support enabled and then, if > used font has ligatures for specific symbol, then those are used. > I finally had some time to delve into this, and indeed that was the problem. The font mapped the pair "<<" to the left guillemot, the pair "--" to an en-dash (although the en-dash glyph was no different than the ordinary hyphen glyph, so it looked like it was dropping one of the pair), along with a handful of other ligatures. Using fontforge I edited the ligature table to remove the ones that were causing a problem. Restarted Thunderbird and presto! all fixed. So many (many!) thanks to Virgo for the suggestion to look at the font itself. I looked in the TB config editor, but couldn't see anything that would turn off the use of ligatures -- which is rather surprising, since it must have been enabled only in the fairly recent past, as I'm using exactly the same fonts I've been using for years without this problem appearing -- but maybe it's in the config editor with an unguessable name. It's also surprising that TB enables ligatures with a monospoaced font, because that's generally not a good idea; but I suppose that if the font itself says it's OK to use a ligature, I can only half-blame TB for using it :-) Anyway, I'm delighted that I can now write: cout << n-- << endl; without a noticeable increase in my blood pressure. Doc -- Web: http://enginehousebooks.com/drevans
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