Crash after unzooming a single terminal inside a tab

[Vulcalien]

To Reproduce
Open Terminator. Open a tab. Zoom the single terminal in it (Ctrl+Shift+X), then unzoom it.

Desktop: (pretty sure it's not relevant)

• OS or Linux Distribution: Linux Mint
• Version: 21
• Display Technology: X11

Describe the bug
Terminator crashes when unzooming a single terminal inside a tab. When there are 2 or more terminals, the issue doesn't occur. I did a git bisect, and found that the commit introducing the bug is 11639159, pushed for PR #810. The problems seems to be here:

#notify plugins of tab-change
dbg("emit tab-change for tabpos: %s " % tabpos)
term_widget.emit('tab-change', tabpos)
self.set_current_page(tabpos)
widget.grab_focus()

in Notebook.newtab. The problem disappears when term_widget.emit('tab-change', tabpos) is removed.

When it doesn't crash, I see an extremely large number of new tabs, all containing the same terminal. Maybe it gets confused by the fact there is only one terminal..?

[vssdeo]

Let me also look into this, this PR seems to be mine. I have figured out the reason for the the trigger, where zoomed terminal calls def tab_change(self, widget, num=None, ignore = None): to unzoom which in turn creates a newtab everytime in a loop. I wanted to reused tab-change event and not add another one. I have two solutions in mind let me get a patch for this.

Terminator::find_terminal_by_uuid: checking: urn:uuid:9c5467f0-a14b-406b-9c11-c814058f4451 (<terminal.Terminal object at 0x7fc5de3c5f00 (terminatorlib+terminal+Terminal at 0x2dc3db0)>) (/home/user/dev/terminator/terminatorlib/terminator.py:187)
Traceback (most recent call last):
  File "/home/user/dev/terminator/terminatorlib/notebook.py", line 519, in do_deferred_on_tab_switch
    self.on_tab_switch(*self.pending_on_tab_switch_args)
  File "/home/user/dev/terminator/terminatorlib/notebook.py", line 527, in on_tab_switch
    term = self.terminator.find_terminal_by_uuid(tabs_last_active_term.urn)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/dev/terminator/terminatorlib/terminator.py", line 189, in find_terminal_by_uuid
    if terminal.get_toplevel().is_child_notebook():
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'Notebook' object has no attribute 'is_child_notebook'

Then on restore (unzoom) it goes into repeat spiral.

Notebook::newtab: creating TabLabel with text: user@kali: ~/dev/terminator (/home/user/dev/terminator/terminatorlib/notebook.py:316)
Notebook::newtab: inserting page at position: 1 (/home/user/dev/terminator/terminatorlib/notebook.py:323)

(terminator:20321): Gtk-WARNING **: 00:47:59.080: Can't set a parent on widget which has a parent
ConfigBase::get_item: detachable_tabs found in globals: True (/home/user/dev/terminator/terminatorlib/config.py:790)
Terminator::find_terminal_by_uuid: searching self.terminals for: urn:uuid:ac750de6-4d46-43f9-bc35-5999788a85e0 (/home/user/dev/terminator/terminatorlib/terminator.py:185)
Terminator::find_terminal_by_uuid: checking: urn:uuid:9c5467f0-a14b-406b-9c11-c814058f4451 (<terminal.Terminal object at 0x7fc5de3c5f00 (terminatorlib+terminal+Terminal at 0x2dc3db0)>) (/home/user/dev/terminator/terminatorlib/terminator.py:187)

[vssdeo]

Removed the tab-change emit code. New pull request has a decoupled plugin code using focus-in event.

[Vulcalien]

I can gladly state that it's fixed now!

[vssdeo]

I can gladly state that it's fixed now!

@Vulcalien thanks for finding this bug on time, else It would have been difficult. In addition thanks to you I was able to implement the code in a simpler way.

[Vulcalien]

I was able to implement the code in a simpler way

That's great, glad to be helpful!