[threads] HelpSheet thread causes an exception

[midichef]

[threads] HelpSheet thread causes an exception

[midichef]

I use it to skip the quitguard. But also the key combination is easier for me to press.

Also, I override the Q binding of quit-sheet-free, and bind it instead to a custom quit function that avoids the quitguard for the current sheet.

[midichef]

Here's what I've found so far.

The exception occurs because t.ident is None. I believe this means the thread has not been started.

The thread here t is sort() for a Helpsheet.

Bisect shows the exception first appears in fde0588, where CommandHelpGetter(type(sheet)) is called:

visidata/visidata/sidebar.py

Line 17 in fde0588

return AttrDict(commands=CommandHelpGetter(type(sheet)),

It creates a HelpSheet:

visidata/visidata/guide.py

Line 118 in fde0588

self.helpsheet = vd.HelpSheet()

And sort() is called from the HelpSheet's afterLoad:

visidata/visidata/sheets.py

Line 290 in fde0588

vd.sync(self.sort())

My first thought was that it may be related to recent changes to how threads work in threads.py in the last few months. But I don't think they are related. I tested older versions of threads.py while keeping the rest of the code at the breaking commit (fde0588). Reverting threads.py to the last stable change in March 2023 (1c1a11e) still had the problem of the occasional exception on quitting, as did more recent commits affecting threads.py from October and November 2023. So it's not caused by those recent changes.

Commenting out self.helpsheet.ensureLoaded() does seem to prevent the exception:

visidata/visidata/guide.py

Line 119 in fde0588

self.helpsheet.ensureLoaded()

[saulpw]

It could also be that the thread finishes after it's put into the list of threads to cancel. But if it's not running we can't cancel it anyway. So we can just check for this to avoid the exception.

BTW, do you have a reason to use Ctrl+Q instead of gq? I think the only difference is that it avoids the quitguard, do you want that behavior, or do you prefer the keybinding, or?