Resizing Analysis Window Causes Crash

[philipbaileynar]

From Luke Worshom via FreshDesk:

Just noticed recently while using the QRis analysis window; may be a known issue.

1. Creating a "new analysis" in QRiS plugin window opens docked analysis window.
2. Undocking analysis window to expand view causes QGIS to crash. This has happened a couple times now.

https://riverscapes.freshdesk.com/a/tickets/194

[philipbaileynar]

I just reproduced this in MacOS.

• QGIS 3.38
• QRiS 1.0.2

I upgraded to QRiS 1.0.7 and the same problem occurs.

Note that I can undock the project explorer dockable widget and it doesn't crash QGIS.

[KellyMWhitehead]

This is an odd one - not quite sure how to debug the qt widget and catch the error.

I have also reproduced this error. It seems if you resize the Analysis panel (i.e. make it taller) before undocking, QGIS does not crash.

[philipbaileynar]

Given that the project explorer (and other QRiS) widgets don't crash, it tells me that one or more widgets on this dockable window are not being created properly.

A few things to try:

1. Are there any widgets being created outside of the dockable window constructor? This could cause them to be disassociated with the parent dockable widget and cause a memory leak.
2. Are there any widgets being created with invalid parents or other parameters that we don't do elsewhere?
3. Try removing all widgets so that the dockable window is empty. Does it still crash? If not, then slowly add back one widget at a time until you find the offending widget. Annoying as all hell, but I can't think of anything else.

[Jdgilby]

@philipbaileynar @KellyMWhitehead Just wanted to add a little more info on this. Its been an issue for a while, I should have posted something sooner... The crash only happens if you immediately undock/resize upon opening widget. It seems it needs to think for a minute. If you give it 10-15 seconds after opening before doing anything it doesn't crash.

[KellyMWhitehead]

This still a bit of a flakey crash that is hard to reproduce. I was able to get the error to show up when 1) the analysis had metric values and 2) I tried to move the window right away after it appeared. My guess is that the form is still loading the metric values and building the table when the user attempts to move it.

I was able to change the order of operations when creating the dockable analysis window that seems to have fixed the issue for me. Please test in the upcoming 1.0.8 release and let me know if this shows up again.