Fix regression spuriously expanding abbr with cursor outside token

Given "abbr foo something", the input sequence

    foo<space><ctrl-z><space>

would re-expand the abbreviation on the second space which is surprising
because the cursor is not at or inside the command token.  This looks to be
a regression from 00432df42 (Trigger abbreviations after inserting process
separators, 2024-04-13)

Happily, 69583f303 (Allow restricting abbreviations to specific commands
(#10452), 2024-04-24) made some changes that mean the bad commit seems no
longer necessary. Not sure why it works but I'll take it.

share/functions/__fish_shared_key_bindings.fish

@@ -105,20 +105,20 @@ function __fish_shared_key_bindings -d "Bindings shared between emacs and vi mod
         or exit # protect against invalid $argv
 
         # Space and other command terminators expands abbrs _and_ inserts itself.
-        bind --preset $argv space self-insert expand-abbr-backtrack
-        bind --preset $argv ";" self-insert expand-abbr-backtrack
-        bind --preset $argv "|" self-insert expand-abbr-backtrack
-        bind --preset $argv "&" self-insert expand-abbr-backtrack
-        bind --preset $argv ">" self-insert expand-abbr-backtrack
-        bind --preset $argv "<" self-insert expand-abbr-backtrack
-        bind --preset $argv shift-enter "commandline -i \n" expand-abbr-backtrack
-        $legacy_bind --preset $argv \e\[27\;2\;13~ "commandline -i \n" expand-abbr-backtrack # Sent with XTerm.vt100.formatOtherKeys: 0
-        bind --preset $argv alt-enter "commandline -i \n" expand-abbr-backtrack
-        bind --preset $argv ")" self-insert expand-abbr-backtrack # Closing a command substitution.
+        bind --preset $argv space self-insert expand-abbr
+        bind --preset $argv ";" self-insert expand-abbr
+        bind --preset $argv "|" self-insert expand-abbr
+        bind --preset $argv "&" self-insert expand-abbr
+        bind --preset $argv ">" self-insert expand-abbr
+        bind --preset $argv "<" self-insert expand-abbr
+        bind --preset $argv shift-enter "commandline -i \n" expand-abbr
+        $legacy_bind --preset $argv \e\[27\;2\;13~ "commandline -i \n" expand-abbr # Sent with XTerm.vt100.formatOtherKeys: 0
+        bind --preset $argv alt-enter "commandline -i \n" expand-abbr
+        bind --preset $argv ")" self-insert expand-abbr # Closing a command substitution.
         bind --preset $argv ctrl-space 'test -n "$(commandline)" && commandline -i " "'
         bind --preset $argv -k nul 'test -n "$(commandline)" && commandline -i " "'
         # Shift-space behaves like space because it's easy to mistype.
-        bind --preset $argv shift-space 'commandline -i " "' expand-abbr-backtrack
+        bind --preset $argv shift-space 'commandline -i " "' expand-abbr
 
         bind --preset $argv enter execute
         bind --preset $argv ctrl-j execute

src/input.rs

@@ -166,7 +166,6 @@ const INPUT_FUNCTION_METADATA: &[InputFunctionMetadata] = &[
     make_md(L!("execute"), ReadlineCmd::Execute),
     make_md(L!("exit"), ReadlineCmd::Exit),
     make_md(L!("expand-abbr"), ReadlineCmd::ExpandAbbr),
-    make_md(L!("expand-abbr-backtrack"), ReadlineCmd::ExpandAbbrBacktrack),
     make_md(L!("force-repaint"), ReadlineCmd::ForceRepaint),
     make_md(L!("forward-bigword"), ReadlineCmd::ForwardBigword),
     make_md(L!("forward-char"), ReadlineCmd::ForwardChar),

src/input_common.rs

@@ -114,7 +114,6 @@ pub enum ReadlineCmd {
     FuncAnd,
     FuncOr,
     ExpandAbbr,
-    ExpandAbbrBacktrack,
     DeleteOrExit,
     Exit,
     CancelCommandline,

src/reader.rs

@@ -3116,13 +3116,6 @@ impl ReaderData {
                     self.inputter.function_set_status(false);
                 }
             }
-            rl::ExpandAbbrBacktrack => {
-                if self.expand_abbreviation_at_cursor(2) {
-                    self.inputter.function_set_status(true);
-                } else {
-                    self.inputter.function_set_status(false);
-                }
-            }
             rl::Undo | rl::Redo => {
                 let (elt, el) = self.active_edit_line_mut();
                 let ok = if c == rl::Undo { el.undo() } else { el.redo() };

tests/checks/tmux-abbr.fish

@@ -24,6 +24,11 @@ isolated-tmux send-keys abbr-test Space C-z arg2 Enter
 tmux-sleep
 # CHECK: prompt {{\d+}}> abbr-test arg2
 
+# Same with a redundant space; it does not expand abbreviations.
+isolated-tmux send-keys C-u abbr-test Space C-z Space arg2 Enter
+tmux-sleep
+# CHECK: prompt {{\d+}}> abbr-test  arg2
+
 # Or use Control+Space ("bind -k nul") to the same effect.
 isolated-tmux send-keys abbr-test C-Space arg3 Enter
 tmux-sleep