SUMMARY This may be related to bug #373232 for Konsole. As in Konsole, Kate displays random horizontal lines when fractional (e.g., 1.3, 1.7) display scaling is used on HiDPI displays. The workaround is to use integer scaling, but this is impractical on many modern devices with 2K or 4K display and laptop-sized displays. STEPS TO REPRODUCE - on hardware with a high resolution screen such as 2K 1. Open System Settings > Display & Monitor > Scale Display 2. Select a non-integer scale factor and save the setting 3. OBSERVED RESULT Horizontal lines randomly appear which are not part of the document, especially when selecting text or scrolling. EXPECTED RESULT A document which is displayed corrected with no extraneous horizontal lines or other visual artifacts. SOFTWARE VERSIONS KDE Plasma Version: 5.13.5 KDE Frameworks Version: 5.50.0 Qt Version: Qt 5.11.1 (built against 5.11.1) QMake version 3.1 ADDITIONAL INFORMATION Please see https://bugs.kde.org/show_bug.cgi?id=373232 https://bugsfiles.kde.org/attachment.cgi?id=109683
I see that Kate was fixed upstream in Qt 5.12: https://bugreports.qt.io/browse/QTBUG-66036 I also see that this is a duplicate of https://bugreports.qt.io/browse/QTBUG-66036
Yes, Qt 5.12 should finally solve this. Let's close this for now - please reopen, if Qt 5.12 does not fix it for you. *** This bug has been marked as a duplicate of bug 373232 ***
*** This bug has been marked as a duplicate of bug 390451 ***