Provide old implementation of cancel-commandline as fallback

__fish_cancel_commandline was unused (even before) and has some issues
on multiline commandlines. Make it use the previously active logic.

Closes fish-shell#10935

CHANGELOG.rst

@@ -94,7 +94,7 @@ Notable improvements and fixes
 
   This build system is experimental; the main build system, using ``cmake``, remains the recommended approach for packaging and installation to a prefix.
 - A new function ``fish_should_add_to_history`` can be overridden to decide whether a command should be added to the history (:issue:`10302`).
-- :kbd:`ctrl-c` during command input no longer prints ``^C`` and a new prompt, but merely clears the command line. This restores the behavior from version 2.2. To revert to the old behavior, use ``bind ctrl-c __fish_cancel_commandline`` (:issue:`10213`).
+- :kbd:`ctrl-c` during command input no longer prints ``^C`` and a new prompt, but merely clears the command line. This restores the behavior from version 2.2. To revert to the old behavior, use ``for mode in (bind --list-modes); bind -M $mode ctrl-c cancel-commandline-traditional; end`` (:issue:`10213`).
 - Bindings can now mix special input functions and shell commands, so ``bind ctrl-g expand-abbr "commandline -i \n"`` works as expected (:issue:`8186`).
 - Special input functions run from bindings via ``commandline -f`` are now applied immediately, instead of after the currently executing binding (:issue:`3031`).
   For example, ``commandline -i foo; commandline | grep foo`` succeeds now.

share/functions/__fish_cancel_commandline.fish

@@ -1,30 +1,4 @@
-function __fish_setup_cancel_text -v fish_color_cancel -v fish_color_normal
-    set -g __fish_cancel_text "^C"
-    if set -q fish_color_cancel
-        set __fish_cancel_text (echo -sn (set_color $fish_color_cancel) $__fish_cancel_text (set_color normal))
-    end
-    if command -sq tput
-        # Clear to EOL (to erase any autosuggestions)
-        set __fish_cancel_text (echo -sn $__fish_cancel_text (tput el; or tput ce))
-    end
-end
-__fish_setup_cancel_text
-
-# This is meant to be bound to something like \cC.
+# This is meant to be bound to something like ctrl-c
 function __fish_cancel_commandline
-    set -l cmd (commandline)
-    if test -n "$cmd"
-        echo -sn $__fish_cancel_text
-        # `commandline -L` prints the line the cursor is on (starting from the prompt), so move the cursor
-        # "to the end" then call `commandline -L` to get the total number of lines typed in at the prompt.
-        commandline -C 10000000
-        printf (string repeat -n (commandline -L) "\n")
-        commandline ""
-        emit fish_cancel
-    end
-
-    # cancel: Close the pager if it's open (#4298)
-    # repaint: Repaint even if we haven't cancelled anything so the prompt refreshes
-    # and the terminal scrolls to it.
-    commandline -f cancel -f repaint
+    commandline -f cancel-commandline-traditional
 end

src/input.rs

@@ -146,6 +146,7 @@ const INPUT_FUNCTION_METADATA: &[InputFunctionMetadata] = &[
     make_md(L!("beginning-of-line"), ReadlineCmd::BeginningOfLine),
     make_md(L!("cancel"), ReadlineCmd::Cancel),
     make_md(L!("cancel-commandline"), ReadlineCmd::CancelCommandline),
+    make_md(L!("cancel-commandline-traditional"), ReadlineCmd::CancelCommandlineTraditional),
     make_md(L!("capitalize-word"), ReadlineCmd::CapitalizeWord),
     make_md(L!("clear-screen"), ReadlineCmd::ClearScreenAndRepaint),
     make_md(L!("complete"), ReadlineCmd::Complete),

src/input_common.rs

@@ -123,6 +123,7 @@ pub enum ReadlineCmd {
     DeleteOrExit,
     Exit,
     CancelCommandline,
+    CancelCommandlineTraditional,
     Cancel,
     Undo,
     Redo,

src/reader.rs

@@ -87,6 +87,7 @@ use crate::kill::{kill_add, kill_replace, kill_yank, kill_yank_rotate};
 use crate::libc::MB_CUR_MAX;
 use crate::nix::isatty;
 use crate::operation_context::{get_bg_context, OperationContext};
+use crate::output::parse_color;
 use crate::output::Outputter;
 use crate::pager::{PageRendering, Pager, SelectionMotion};
 use crate::panic::AT_EXIT;
@@ -2305,7 +2306,7 @@ impl<'a> Reader<'a> {
                 self.data
                     .update_buff_pos(EditableLineTag::Commandline, Some(self.command_line_len()));
             }
-            rl::CancelCommandline => {
+            rl::CancelCommandline | rl::CancelCommandlineTraditional => {
                 if self.conf.exit_on_interrupt {
                     self.parser
                         .set_last_statuses(Statuses::just(STATUS_CMD_ERROR.unwrap()));
@@ -2315,10 +2316,37 @@ impl<'a> Reader<'a> {
                 if self.command_line.is_empty() {
                     return;
                 }
+                if c == rl::CancelCommandlineTraditional {
+                    // Move cursor to the end of the line.
+                    let end = self.command_line.len();
+                    self.update_buff_pos(EditableLineTag::Commandline, Some(end));
+                    self.autosuggestion.clear();
+                    // Repaint also changes the actual cursor position
+                    if self.is_repaint_needed(None) {
+                        self.layout_and_repaint(L!("cancel"));
+                    }
+
+                    let mut outp = Outputter::stdoutput().borrow_mut();
+                    if let Some(fish_color_cancel) = self.vars().get(L!("fish_color_cancel")) {
+                        outp.set_color(
+                            parse_color(&fish_color_cancel, false),
+                            parse_color(&fish_color_cancel, true),
+                        );
+                    }
+                    outp.write_wstr(L!("^C"));
+                    outp.set_color(RgbColor::RESET, RgbColor::RESET);
+
+                    // We print a newline last so the prompt_sp hack doesn't get us.
+                    outp.push(b'\n');
+                }
                 self.push_edit(
                     EditableLineTag::Commandline,
                     Edit::new(0..self.command_line_len(), L!("").to_owned()),
                 );
+                if c == rl::CancelCommandlineTraditional {
+                    self.screen
+                        .reset_abandoning_line(usize::try_from(termsize_last().width).unwrap());
+                }
 
                 // Post fish_cancel.
                 event::fire_generic(self.parser, L!("fish_cancel").to_owned(), vec![]);
@@ -5002,6 +5030,7 @@ fn command_ends_paging(c: ReadlineCmd, focused_on_search_field: bool) -> bool {
         | rl::AcceptAutosuggestion
         | rl::DeleteOrExit
         | rl::CancelCommandline
+        | rl::CancelCommandlineTraditional
         | rl::Cancel =>
         // These commands always end paging.
         {