This is not an issue with the terminals, this is a new feature of bash-5.1. Search for the word "highlight" at https://lists.gnu.org/archive/html/info-gnu/2020-12/msg00003.html .
--- This could not theoretically be a bug in gnome-terminal/vte. Terminals don't directly paint a letter as a consequence of the user pressing that letter, or pasting something. I'm certain you can think of plenty of cases where pressing a certain letter does not cause that letter to be painted on the canvas, but some other action (larger repaints), or perhaps nothing at all. When you press a letter, or paste some text, it is forwarded towards the kernel over the tty line, but is not displayed. The kernel then might handle it itself, or forward further towards some application (e.g. bash in this case). Then that application may or may not decide to paint something. Whatever it decides to paint may or may not be the same as the typed letter or pasted text. But even if it's the same, the terminal has no way of making this connection. "The user pressed the letter X, I've forwarded it, 100 milliseconds later I received a letter X to be painted, it must be the «same» X" -- it cannot work like this. What happens in this particular case is that you paste "foo", and in response bash instructs the terminal to print "foo" in inverse colors. The terminal does what it must do: obeys this instuction (without having the slightest idea that it's related to the paste). --- Two more things to mention to complete the picture: There is a so-called "bracketed paste mode", where special markers are inserted at the beginning and end of pasted data. This is how applications (bash in this case) can distinguish it from data typed by the user, without relying on timing heuristics. Also, some terminals have a legacy "local echo" mode where pressed keys immediately appear on the screen. I'm fairly certain it's not used anywhere nowadays. Most terminals don't support it, and VTE removed it in version 0.60, see https://gitlab.gnome.org/GNOME/vte/-/issues/69 . ** Bug watch added: gitlab.gnome.org/GNOME/vte/-/issues #69 https://gitlab.gnome.org/GNOME/vte/-/issues/69 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to bash in Ubuntu. https://bugs.launchpad.net/bugs/1926256 Title: Pasted text in the terminal is always highlighted and selected Status in bash package in Ubuntu: Confirmed Status in gnome-terminal package in Ubuntu: Invalid Status in mate-terminal package in Ubuntu: Confirmed Status in vte2.91 package in Ubuntu: Confirmed Bug description: Steps to reproduce: 1. Have Ubuntu 21.04 installed 2. Launch terminal 3a. Execute some command, select this command to copy it, then paste command 3b. Paste some command from clipboard to terminal Expected result: * pasted command is not highlighted and is not selected Actual result: * pasted command is selected and highlighted ProblemType: Bug DistroRelease: Ubuntu 21.04 Package: mate-terminal 1.24.1-1 ProcVersionSignature: Ubuntu 5.11.0-16.17-generic 5.11.12 Uname: Linux 5.11.0-16-generic x86_64 ApportVersion: 2.20.11-0ubuntu65 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: MATE Date: Tue Apr 27 09:43:56 2021 InstallationDate: Installed on 2021-04-23 (3 days ago) InstallationMedia: Ubuntu-MATE 21.04 "Hirsute Hippo" - Release amd64 (20210420) SourcePackage: mate-terminal UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1926256/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp