"commandline -f foo" to skip queue and execute immediately

Commit c3cd68dda (Process shell commands from bindings like regular char
events, 2024-03-02) mentions a "weird ordering difference".
The issue is that "commandline -f foo" goes through the input
queue while other commands are executed directly.
For example

    bind ctrl-g "commandline -f end-of-line; commandline -i x"

is executed in the wrong order. Fix that.

This doesn't yet work for "commandline -f exit" but that can be fixed easily.

It's hard to imagine anyone would rely on the existing behavior.  "commandline
-f" in bindings is mostly used for repainting the commandline.

CHANGELOG.rst

@@ -107,6 +107,8 @@ Interactive improvements
 New or improved bindings
 ^^^^^^^^^^^^^^^^^^^^^^^^
 - 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.
+  For example, ``commandline -f yank -f yank-pop`` inserts the last-but-one entry from the kill ring.
 - When the cursor is on a command that resolves to an executable script, :kbd:`Alt-O` will now open that script in your editor (:issue:`10266`).
 - Two improvements to the :kbd:`Alt-E` binding which edits the commandline in an external editor:
   - The editor's cursor position is copied back to fish. This is currently supported for Vim and Kakoune.

src/builtins/commandline.rs

@@ -12,7 +12,8 @@ use crate::parse_util::{
 };
 use crate::proc::is_interactive_session;
 use crate::reader::{
-    commandline_get_state, commandline_set_buffer, commandline_set_search_field, reader_queue_ch,
+    commandline_get_state, commandline_set_buffer, commandline_set_search_field,
+    reader_execute_readline_cmd,
 };
 use crate::tokenizer::TOK_ACCEPT_UNFINISHED;
 use crate::tokenizer::{TokenType, Tokenizer};
@@ -298,8 +299,6 @@ pub fn commandline(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr])
 
     let positional_args = w.argv.len() - w.woptind;
 
-    let ld = parser.libdata();
-
     if function_mode {
         // Check for invalid switch combinations.
         if buffer_part.is_some()
@@ -335,13 +334,13 @@ pub fn commandline(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr])
             // Don't enqueue a repaint if we're currently in the middle of one,
             // because that's an infinite loop.
             if matches!(cmd, rl::RepaintMode | rl::ForceRepaint | rl::Repaint) {
-                if ld.pods.is_repaint {
+                if parser.libdata().pods.is_repaint {
                     continue;
                 }
             }
 
             // Inserts the readline function at the back of the queue.
-            reader_queue_ch(CharEvent::from_readline(cmd));
+            reader_execute_readline_cmd(CharEvent::from_readline(cmd));
         }
 
         return STATUS_CMD_OK;
@@ -473,8 +472,13 @@ pub fn commandline(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr])
     } else if let Some(override_buffer) = &override_buffer {
         current_buffer = override_buffer;
         current_cursor_pos = current_buffer.len();
-    } else if !ld.transient_commandlines.is_empty() && !cursor_mode {
-        transient = ld.transient_commandlines.last().unwrap().clone();
+    } else if !parser.libdata().transient_commandlines.is_empty() && !cursor_mode {
+        transient = parser
+            .libdata()
+            .transient_commandlines
+            .last()
+            .unwrap()
+            .clone();
         current_buffer = &transient;
         current_cursor_pos = transient.len();
     } else if rstate.initialized {

src/reader.rs

@@ -904,10 +904,14 @@ pub fn reader_schedule_prompt_repaint() {
     }
 }
 
-/// Enqueue an event to the back of the reader's input queue.
-pub fn reader_queue_ch(ch: CharEvent) {
+pub fn reader_execute_readline_cmd(ch: CharEvent) {
     if let Some(data) = current_data() {
-        data.inputter.queue_char(ch);
+        if data.rls.is_none() {
+            data.rls = Some(ReadlineLoopState::new());
+        }
+        data.apply_commandline_state_changes();
+        data.handle_char_event(Some(ch));
+        data.update_commandline_state();
     }
 }
 

tests/pexpects/bind.py

@@ -358,6 +358,20 @@ send('\x02\x02\x02') # ctrl-b, backward-char
 sendline('\x1bu') # alt+u, upcase word
 expect_prompt("fooBAR")
 
+send("""
+    bind ctrl-g "
+        commandline --insert 'echo foo ar'
+        commandline -f backward-word
+        commandline --insert b
+        commandline -f backward-char
+        commandline -f backward-char
+        commandline -f delete-char
+    "
+""")
+send('\x07') # ctrl-g
+send('\r')
+expect_prompt("foobar")
+
 # Check that the builtin version of `exit` works
 # (for obvious reasons this MUST BE LAST)
 sendline("function myexit; echo exit; exit; end; bind ctrl-z myexit")