Make cancel-commandline actual bind function

This was always awkward as fish script, and had problems with
interrupting the autoloading.

Note that we still leave the old function intact to facilitate easier
upgrading for now.

Fixes #7145.

doc_src/cmds/bind.rst

@@ -98,6 +98,8 @@ The following special input functions are available:
 
 - ``cancel``, cancel the current commandline and replace it with a new empty one
 
+- ``cancel-commandline``, cancel the current commandline and replace it with a new empty one, leaving the old one in place with a marker to show that it was cancelled
+
 - ``capitalize-word``, make the current word begin with a capital letter
 
 - ``complete``, guess the remainder of the current token

share/functions/__fish_shared_key_bindings.fish

@@ -89,7 +89,7 @@ function __fish_shared_key_bindings -d "Bindings shared between emacs and vi mod
     # ncurses > 6.0 sends a "delete scrollback" sequence along with clear.
     # This string replace removes it.
     bind --preset $argv \cl 'echo -n (clear | string replace \e\[3J ""); commandline -f repaint'
-    bind --preset $argv \cc __fish_cancel_commandline
+    bind --preset $argv \cc cancel-commandline
     bind --preset $argv \cu backward-kill-line
     bind --preset $argv \cw backward-kill-path-component
     bind --preset $argv \e\[F end-of-line

share/functions/fish_vi_key_bindings.fish

@@ -67,7 +67,7 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
 
     # Default (command) mode
     bind -s --preset :q exit
-    bind -s --preset -m insert \cc __fish_cancel_commandline
+    bind -s --preset -m insert \cc cancel-commandline
     bind -s --preset -M default h backward-char
     bind -s --preset -M default l forward-char
     bind -s --preset -m insert \n execute

src/input.cpp

@@ -148,6 +148,7 @@ static const input_function_metadata_t input_function_metadata[] = {
     {readline_cmd_t::func_and, L"and"},
     {readline_cmd_t::expand_abbr, L"expand-abbr"},
     {readline_cmd_t::delete_or_exit, L"delete-or-exit"},
+    {readline_cmd_t::cancel_commandline, L"cancel-commandline"},
     {readline_cmd_t::cancel, L"cancel"},
     {readline_cmd_t::undo, L"undo"},
     {readline_cmd_t::redo, L"redo"},

src/input_common.h

@@ -71,6 +71,7 @@ enum class readline_cmd_t {
     func_and,
     expand_abbr,
     delete_or_exit,
+    cancel_commandline,
     cancel,
     undo,
     redo,

src/reader.cpp

@@ -1174,6 +1174,7 @@ static bool command_ends_paging(readline_cmd_t c, bool focused_on_search_field)
         case rl::history_token_search_forward:
         case rl::accept_autosuggestion:
         case rl::delete_or_exit:
+        case rl::cancel_commandline:
         case rl::cancel: {
             // These commands always end paging.
             return true;
@@ -2673,6 +2674,29 @@ void reader_data_t::handle_readline_command(readline_cmd_t c, readline_loop_stat
             mark_repaint_needed();
             break;
         }
+        case rl::cancel_commandline: {
+            if (command_line.size()) {
+                outputter_t &outp = outputter_t::stdoutput();
+                // Move cursor to the end of the line.
+                update_buff_pos(&command_line, command_line.size());
+                // Repaint also changes the actual cursor position
+                repaint();
+
+                auto fish_color_cancel = vars.get(L"fish_color_cancel");
+                if (fish_color_cancel) {
+                    outp.set_color(parse_color(*fish_color_cancel, false), parse_color(*fish_color_cancel, true));
+                }
+                outp.writestr(L"^C");
+                outp.set_color(rgb_color_t::reset(), rgb_color_t::reset());
+
+                // We print a newline last so the prompt_sp hack doesn't get us.
+                outp.push_back('\n');
+
+                set_command_line_and_position(&command_line, L"", 0);
+                s_reset_abandoning_line(&screen, termsize_last().width - command_line.size());
+            }
+            break;
+        }
         case rl::cancel: {
             // The only thing we can cancel right now is paging, which we handled up above.
             break;