Bug 508103

Created attachment 183945 [details]
Font changing spacing as font size changes

SUMMARY

When Ascii characters are enabled, the amount of space a character actually takes up and the visual element of that character becomes desynched. For a long string with no spaces, the cursor can stray rather far from the expected position, and adding a space at the long words aligns the next character to the end of where the word should be, rather than where it is, which can cause a space to appear extremly large or overlab between characters. The position of the cursor on the line can also impact how the characters are rendered

STEPS TO REPRODUCE
1. Enable ASCII characters in Profile->Appearance->Complex Text Layout
2. Type a very long, single word, then a space, then a shorter word
(I tested with the string below)
3. Scroll through different fontsizes.

asdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfadfadsfadfadfasdfasdfadfasdfasdfasdfasdfadsfadsfasdfasdfasdfasdfasdfasdfasdfadsfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfassdf testexit

(adjust with each font so it fits on one line) - optimally, test as large of a screen as possible, as the effect is more pronouced the more columns there are 

OBSERVED RESULT

Hack 4pt - extremly large space
hack 5pt - overlap
Hack 6pt - extremly large space
Hack 7pt - almost right, space is slightly smaller than expected
Hack 8pt - large space 
Hack 9pt - overlap
Hack 10pt - large space 
Hack 11pt - space slightly smaller than expected, looks almost normal (it's like a quarter character shorter than it should be after ~400columns)
Hack 12pt - large space 
Hack 13pt - overlap
Hack 14pt - overlap
Hack 15pt - space is extremly small
Hack 16pt - space is wider than expected
Hack 17pt - space is slightly wider than expected
Hack 18pt - overlap

EXPECTED RESULT

text should not overlap, and the space should be the same width as all the other characters since the font is monospace for all font sizes

SOFTWARE/OS VERSIONS
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: EndevourOS, just updated at time of posting
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Konsole Version: 25.04.3

Additional Notes
May possibly be related to Bug #433604, though that is showing as Resolved+Fixed from a much older version. I have not had the chance to try older versions of Konsole to figure out when this bug appeared