Middle-clicking twice quickly, results in text pasted 3 times instead of 2

[DrLex0]

Describe the bug
Middle-clicking twice in quick succession, will paste text 3 times instead of the expected 2 times. It's on the second click that the text is pasted one time too many, resulting in a total of 3 pastings.
It also happens when pressing a key in between the 2 clicks.
Happens in every system I have tried, including VMs, with every mouse I have tried, also emulated mouse in VMs. So please don't tell me it's bad debouncing or whatever, it is not.
I suspect the time threshold for the bug to occur might coincide with the double-click threshold.

To Reproduce
Select some text and then middle-click twice inside a Terminator window, with very little time in between.

Expected behavior
Text is pasted twice, once of each click.

Desktop (please complete the following information):

• OS or Linux Distribution: Ubuntu
• Version: 22.04 (Jammy), already present in Bionic and probably earlier. Terminator version 2.1.1-1
• Display Technology: X11

Additional context
I won't even tell how much time I have wasted on this, by thinking the mouse was at fault, and then replacing mice or trying to clean the switch with contact cleaner. Please fix this.

[mattrose]

Can confirm. It even happens with 2.1.4 on Ubuntu 22.04.

Never noticed this before, sorry it's been driving you nuts.

Having said that, it might be tricky to track down what's causing it, but I'll take a look

[egmontkob]

My first thought was that it's handled entirely by VTE, isn't it? However, other VTE+GTK3-based terminals don't suffer from this issue.

Yet VTE+GTK4-based ones that I could try quickly (i.e. kgx and blackbox) do suffer from a similar problem in the opposite direction: the text isn't pasted on the second or third click. (Update: just filed https://gitlab.gnome.org/GNOME/vte/-/issues/2790 for this.)

(Double and triple clicks are handled differently in GTK3 vs. GTK4: https://gitlab.gnome.org/GNOME/vte/-/issues/2648)

Anyway, I still think it could be partially VTE's fault, dunno.

[mattrose]

I suspect it's something in the way that we handle the middle-mouse clicks. there's so much special case code around copying and pasting that I wouldn't be suprised if we were doing something unusual there. It's probably that, combined with a VTE problem 😄