I'm using fedora fc31 with plasma 5.18.5/kf5 5.70 Independent on the settings of systemsettings5 > window management > window behavior > titlebar actions > double-click, the window does not maximize/minimize/shade (whatever) on a double-click inside the title-bar Instead, the behavior is similar to the 'move window' action (e.g. like clicking Alt+primary mouse key and moving the mouse) Double-clicking is indeed working properly inside of windows (e.g. selecting text), so i assume this to be a glitch/bug..?
some more information: this happens only by changing the 'animation speed' in systemsettings5 > workspace behavior > general behavior (after logoff/login all is fine again, double-clicking on titlebar works as expected. Change the slider setttings - and double click is gone)
Same with freshly installed Fedora 32
QApplication::startDragTime() is getting broken
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-integration/-/merge_requests/5
Git commit 857ee264e62e68dfa7c5ce7086dc6fc4195234a5 by David Edmundson. Committed on 14/09/2020 at 22:00. Pushed by davidedmundson into branch 'master'. Use same default for all places StartDragTime is loaded On startup we call: m_hints[QPlatformTheme::StartDragTime] = readConfigValue(cg, QStringLiteral("StartDragTime"), 500); on reload we call int startDragTime = cg.readEntry("StartDragTime", 10); if the startup time isn't set, then if a reload is triggered then it is reset to a bogus value. Long term this clearly needs porting to KConfigXT M +1 -1 src/platformtheme/khintssettings.cpp https://invent.kde.org/plasma/plasma-integration/commit/857ee264e62e68dfa7c5ce7086dc6fc4195234a5
*** Bug 345473 has been marked as a duplicate of this bug. ***
Oops sorry about the spam everyone I got very confused with bugzilla's interface and then fatfingered the enter key and commited a bunch of stupid changes to a necro'd resolved bug which I have just reverted much apologies.