Sigil Crashes when Plugin Runner closed with X-button

[Tex2002ans]

I got a bug to report... crash, closes right out of Sigil, no warning.

Don't know if this is a Sigil plugin bug, or a bug with your specific plugin.

Steps to Reproduce

1. Highlight a file in Book Browser.

Plugins > Edit > TagMechanic

2. Without doing anything, close out using the "Plugin Runner" X:



Sigil just crashes.

I tested it about 6 times:

5/6 Sigil closed with zero warning.
1/6 Sigil popped up some sort of XML parsing warning (but I forgot to screenshot it). Sigil then crashed soon after.

[odamizu]

I am not experiencing this with either 0.9.18 or 0.9.991. However, I am on macOS.

[Doitsu]

I've tested the plugin on my 64bit Windows 10 (1909) machine with Sigil 0.9.14 and Sigil 0.9.991-51 and didn't experience any crashes. All I got was the Error Parsing Result XML: Premature end of document message box.

@Tex2002ans what's your operating system?

[BeckyEbook]

This has always been the case with plugins that use tkinter. A new window is opened and the launcher window is a bit vulnerable when the user wants to close (or cancel) it.

Crash is not every time, but sometimes it closes Sigil, and sometimes it's just a message.
One of two messages appears:
* Error Parsing Result XML: Start tag expected.
* Error Parsing Result XML: Encountered incorrectly encoded content.

Personally, I have always "avoided" closing because I've encountered the problem a few years ago.

[Tex2002ans]

Originally Posted by Doitsu

@Tex2002ans what's your operating system?

Sigil 0.9.14
Windows 10 1903 (64-bit)

Originally Posted by BeckyEbook

* Error Parsing Result XML: Encountered incorrectly encoded content.

Just tested again, and this time I got this popup.

Without even clicking on it, Sigil then disappeared.

Originally Posted by BeckyEbook

Personally, I have always "avoided" closing because I've encountered the problem a few years ago.

Yeah me too... but I was unsure of some code, was looking at the PDF on the left half of my screen, and clicked on the first X I saw out of the corner of my eye.

Next thing I knew, Sigil crashed, and I lost a few minutes of work (luckily I save new versions every time I reach a new milestone).

[DiapDealer]

A plugin can't crash Sigil. Not without some very devious and malicious intent, anyway. The simple answer is "don't close Sigil's Plugin Runner out from under a plugin that the Plugin Runner is running/monitoring."

We'll see if we can fix Sigil so it doesnt crash, but in the meantime, this is very much a "Doctor, it hurts whenever I do this" type of scenario.

And it's nothing to do with tkinter per se. It's the fact that there's simply no time to hit the x button on a plugin that does its work immediately (with no gui to select options). It's theoretically possible to crash Sigi! this way with any plugin out there (if one is quick enough on the mouse).

[KevinH]

I do not get any crash either but I am on macOS. It should never crash. Those error messages about missing ResultXML just means any output from the plugin itself was incomplete but that should not crash Sigil.

Does using the Cancel button instead of the X on PluginRunner cause a crash of Sigil too?

If using Cancel does not crash Sigil, we can try to override the closeEvent and have it call Cancel before exiting.

[DiapDealer]

Originally Posted by KevinH

Does using the Cancel button instead of the X on PluginRunner cause a crash of Sigil too?

I can't get Sigil to crash with the steps given either on Windows 10. My guess is that Cancel would never crash (for those who are experiencing them when hitting the X button). If so, I'd be tempted to see if we can intercept that X button signal and do the same thing with it that the Cancel button does. I'd say hide the close button box, but the escape key on Windows will do the same thing. So we might have to catch that in Plugin Runner as well.

Another option would be to hide the Plugin Runner window until the plugin returns control. But I don't like that for several obvious reasons.

[KevinH]

I forgot about escape. From what I have read, Escape will not generate a closeEvent we could actually catch. So we might as you said have to filter out escape key events.

[BeckyEbook]

The Cancel button does not crash.

It is difficult for me to determine the exact frequency because I never really close the launcher with "X". I only checked it today after reading the post. Sometimes it sigil crash the first time and sometimes the second or third time.

[KevinH]

This should now be fixed in master by overiding QDialog::reject() to invoke cancelPlugin first before exiting and by my tests this catches both the escape key and the x close.

BeckyEbook, if you do a fresh build today, would you please see if this stops the crashing as I can not test it on my mac as it doesn't crash at all

[DiapDealer]

Originally Posted by KevinH

This should now be fixed in master by overiding QDialog::reject() to invoke cancelPlugin first before exiting and by my tests this catches both the escape key and the x close.

Doitsu clued me in to one of his plugins that would consistently crash for me when clicking the close button (or hitting ESC) while the plugin's gui (PyQt5) was open. Your commit eliminated the crashing (using ESC as well)

[DiapDealer]

I'm going to split this conversation out into its own thread since it's not a plugin bug.

[KevinH]

Great to know it works. And we should definitely split this intoits own thread just for the records sake as well.

Originally Posted by DiapDealer

I'm going to split this conversation out into its own thread since it's not a plugin bug.

[BeckyEbook]

Crash exist.

Debug: Warning: QProcess: Destroyed while process ("C:\\Program Files\\Sigil\\python3.exe") is still running.