Bug 421586

+++ This bug was initially created as a clone of Bug #421540 +++
[Frameworks/plasma git-master, so this is the redesigned window rules kcm.  qt-5.15.0_rc ]

Yet another bug with the new rules kcm implementation.  Apparently the placement setting has a problem at least somewhat similar to the window sizing items.  It doesn't seem to load properly when a ruleset is loaded, and while applying a change to something else doesn't /always/ seem to modify the placement setting (that wasn't deliberately changed), when it /does/ get overwritten, it seems to always be with force, top-left.  Once changed to that, it appears to be impossible to change it to anything else from the kcm as nothing sticks.  IOW, there's some inconsistency in when it's rewritten that I haven't quite pinned down.

The specific scenario here is that I have two konsole profiles with two separate rulesets applying to them, the normal one that's set for 1280x1080 (1/6 of a 4k monitor, 1/2 height, 1/3 width) no placement, and a bit less opacity, and a "popup" one that's set to a smaller 720x450 size, a bit higher opacity, and placement "under mouse".

Something happened, I guessed related to whole window class processing (bug #421542) but possibly not, anyway, I went to toggle off the full window class match as I /thought/ it didn't seem to be working any more on the main konsole ruleset because opacity seemed to be too high.  So I adjusted the main entry's full window class, testing that it was matching again by adjusting opacity, since I wanted to tweak it a bit anyway.

That worked, but then I needed to adjust the opacity on the popup profile's konsole as well.

Somewhere along the line, both the popup konsole's ruleset and the main konsole's ruleset got forced to top-left placement, tho I hadn't touched that at all!  I first noticed it with the popup when I tried to hotkey-launch it and it didn't appear under the mouse as expected.  But after trying to launch it again and not seeing it, I realized what I had been working in lost focus, so went looking, and there the popups were, clear over on the far left of the left-hand 75-inch monitors, literally nearly 2 meters/yards from where I was expecting them due to the size of the monitors!  In trying to fix that I launched a normal konsole and realized it was launching at the top-left as well, so both rulesets had been affected.

I quickly found out that setting the placement back to default for the main konsole ruleset, and under mouse for the popup one, just didn't work from the kcm.  The setting in the rules kcm would change but it wouldn't affect anything and would appear to be set to default when I reloaded the ruleset in the kcm.

Fortunately I had some other rulesets with placement set similar that I hadn't messed with and that thus hadn't been affected, so I could find the settings in kwinrulesrc for them and manually edit the konsole sessions appropriately.  A kwin_x11 --replace later and the behavior was restored.

After that I tested a bit, but I couldn't quite figure out exactly what it was doing, only that sometimes changing another setting and hitting apply screwed up the placement setting too, while sometimes it seemed to leave it alone.  It /did/ seem that the placement setting more consistently got rewritten if I changed opacity compared to some of the other settings, but I'm not 100% sure on that either, only that something's rewriting the placement settings /sometimes/ but as best I could figure out, not /always/.  It didn't seem entirely consistent, which was almost as disturbing as the fact that it was rewriting the placement when I hadn't touched it, in the first place!