> It's never the terminal emulator (whether GNOME Terminal or any other terminal app) that decides what to print on a backspace keypress. The only thing it does is that it tells over the tty line that the backspace key has been pressed.
Makes sense. However, the user thinks of gnome-terminal because that's what he runs... > If your input method cannot generate the symbols you need, and you need to press backspace as a workaround to get that, moreover, you need to rely on one particular behavior of backspace, then I'd argue that it's all the fault of your input method, it should be able to produce straight away whatever you wish to end up with. Unfortunately that's not always possible. Please take a look at the wiki page under [1]. With complex writing systems there's more than one way to write a word which look 'correct' on the screen, but the order of the code points is different [2]. Not very good if you search for that word. Therefore Keyman allows to define keyboards that can auto-correct words so that you end up with the same order of the code points regardless which way you type [3]. And that requires to replace some codepoints typed previously. > Maybe the bug you _really_ wanted to report is that gnome-terminal doesn't use the "surrounding text" feature of input methods? That would be nice to have but until then it would be good to have backspace working properly. But as you wrote in an earlier comment that has nothing to do with gnome-terminal... [1] https://github.com/keymanapp/keyman/wiki/Backspace-and-cluster-deletion [2] https://www.sil.org/resources/archives/91817 [3] https://help.keyman.com/keyboard/khmer_angkor/1.0.7/KAK_Documentation_EN.pdf ** Also affects: bash (Ubuntu) Importance: Undecided Status: New -- 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/2051371 Title: Backspace in gnome-terminal often deletes cluster Status in bash package in Ubuntu: New Status in gnome-terminal package in Ubuntu: New Bug description: If I have ខែ្ (U+1781 U+17c2 U+17d2) in the terminal and press backspace, the first backspace deletes U+17c2 U+17d2 so that I'm left with ខ (U+1781). Instead it should only delete the last codepoint, U+17d2. If I have ខែ (U+1781 U+17c2) a backspace deletes only U+17c2, similarly if I have ខ្ (U+1781 U+17d2) where the backspace deletes U+17d2. Further investigations show that backspace often deletes the entire cluster, i.e. diacritic(s) plus the base character, for example with x̣́ (U+0078 U+0301 U+0323) where a backspace deletes all three codepoints. gnome-terminal should only delete the last codepoint [1]. A real live example where this behavior is problematic is when using ibus-keyman with the Khmer Angkor keyboard [2]. When typing xEjmr the expected output is ខ្មែរ (U+1781 U+17d2 U+1798 U+17c2 U+179a). Keyman does some reordering while typing to put the codepoints in a standardized order. Because gnome-terminal lacks support for surrounding text, the codepoints have to be deleted by emitting several backspace keypresses. Because of the deletion of the cluster the result in gnome-terminal is ្មែរ (U+17d2 U+1798 U+17c2 U+179a). [1] https://github.com/keymanapp/keyman/wiki/Backspace-and-cluster-deletion [2] https://github.com/keymanapp/keyman/issues/10481 ProblemType: Bug DistroRelease: Ubuntu 22.04 Package: gnome-terminal 3.44.0-1ubuntu1 [modified: usr/libexec/gnome-terminal-server] ProcVersionSignature: Ubuntu 6.5.0-14.14~22.04.1-generic 6.5.3 Uname: Linux 6.5.0-14-generic x86_64 ApportVersion: 2.20.11-0ubuntu82.5 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Fri Jan 26 12:21:42 2024 InstallationDate: Installed on 2022-04-12 (653 days ago) InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Beta amd64 (20220329.1) SourcePackage: gnome-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/2051371/+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
