Correctly handle escaping in completion (helix-editor#4316)

* Correctly handle escaping in completion

* Added escaping tests

Author: mitsuhiko

helix-core/src/shellwords.rs

@@ -1,5 +1,22 @@
 use std::borrow::Cow;
 
+/// Auto escape for shellwords usage.
+pub fn escape(input: &str) -> Cow<'_, str> {
+    if !input.chars().any(|x| x.is_ascii_whitespace()) {
+        Cow::Borrowed(input)
+    } else if cfg!(unix) {
+        Cow::Owned(input.chars().fold(String::new(), |mut buf, c| {
+            if c.is_ascii_whitespace() {
+                buf.push('\\');
+            }
+            buf.push(c);
+            buf
+        }))
+    } else {
+        Cow::Owned(format!("\"{}\"", input))
+    }
+}
+
 /// Get the vec of escaped / quoted / doublequoted filenames from the input str
 pub fn shellwords(input: &str) -> Vec<Cow<'_, str>> {
     enum State {
@@ -226,4 +243,18 @@ mod test {
         ];
         assert_eq!(expected, result);
     }
+
+    #[cfg(unix)]
+    fn test_escaping_unix() {
+        assert_eq!(escape("foobar"), Cow::Borrowed("foobar"));
+        assert_eq!(escape("foo bar"), Cow::Borrowed("foo\\ bar"));
+        assert_eq!(escape("foo\tbar"), Cow::Borrowed("foo\\\tbar"));
+    }
+
+    #[test]
+    #[cfg(windows)]
+    fn test_escaping_windows() {
+        assert_eq!(escape("foobar"), Cow::Borrowed("foobar"));
+        assert_eq!(escape("foo bar"), Cow::Borrowed("\"foo bar\""));
+    }
 }

helix-term/src/commands/typed.rs

@@ -2183,12 +2183,10 @@ pub(super) fn command_mode(cx: &mut Context) {
             static FUZZY_MATCHER: Lazy<fuzzy_matcher::skim::SkimMatcherV2> =
                 Lazy::new(fuzzy_matcher::skim::SkimMatcherV2::default);
 
-            // we use .this over split_whitespace() because we care about empty segments
-            let parts = input.split(' ').collect::<Vec<&str>>();
-
             // simple heuristic: if there's no just one part, complete command name.
             // if there's a space, per command completion kicks in.
-            if parts.len() <= 1 {
+            // we use .this over split_whitespace() because we care about empty segments
+            if input.split(' ').count() <= 1 {
                 let mut matches: Vec<_> = typed::TYPABLE_COMMAND_LIST
                     .iter()
                     .filter_map(|command| {
@@ -2204,12 +2202,13 @@ pub(super) fn command_mode(cx: &mut Context) {
                     .map(|(name, _)| (0.., name.into()))
                     .collect()
             } else {
+                let parts = shellwords::shellwords(input);
                 let part = parts.last().unwrap();
 
                 if let Some(typed::TypableCommand {
                     completer: Some(completer),
                     ..
-                }) = typed::TYPABLE_COMMAND_MAP.get(parts[0])
+                }) = typed::TYPABLE_COMMAND_MAP.get(&parts[0] as &str)
                 {
                     completer(editor, part)
                         .into_iter()

helix-term/src/ui/prompt.rs

@@ -1,5 +1,6 @@
 use crate::compositor::{Component, Compositor, Context, Event, EventResult};
 use crate::{alt, ctrl, key, shift, ui};
+use helix_core::shellwords;
 use helix_view::input::KeyEvent;
 use helix_view::keyboard::KeyCode;
 use std::{borrow::Cow, ops::RangeFrom};
@@ -335,7 +336,10 @@ impl Prompt {
 
         let (range, item) = &self.completion[index];
 
-        self.line.replace_range(range.clone(), item);
+        // since we are using shellwords to parse arguments, make sure
+        // that whitespace in files is properly escaped.
+        let item = shellwords::escape(item);
+        self.line.replace_range(range.clone(), &item);
 
         self.move_end();
     }