Mitigate the poor interaction between ndots expansion and non-path st…

…rings (#13218)

# Description

@hustcer reported that slashes were disappearing from external args
since #13089:

```
$> ossutil ls oss:https://abc/b/c
Error: invalid cloud url: "oss:/abc/b/c", please make sure the url starts with: "oss:https://"

$> ossutil ls 'oss:https://abc/b/c'
Error: oss: service returned error: StatusCode=403, ErrorCode=UserDisable, ErrorMessage="UserDisable", RequestId=66791EDEFE87B73537120838, Ec=0003-00000801, Bucket=abc, Object=
```

I narrowed this down to the ndots handling, since that does path parsing
and path reconstruction in every case. I decided to change that so that
it only activates if the string contains at least `...`, since that
would be the minimum trigger for ndots, and also to not activate it if
the string contains `:https://`, since it's probably undesirable for a URL.

Kind of a hack, but I'm not really sure how else we decide whether
someone wants ndots or not.

# User-Facing Changes
- bare strings not containing ndots are not modified
- bare strings containing `:https://` are not modified

# Tests + Formatting
Added tests to prevent regression.

crates/nu-command/src/system/run_external.rs

@@ -64,7 +64,9 @@ impl Command for External {
 
  let expanded_name = match &name {
  // Expand tilde and ndots on the name if it's a bare string / glob (#13000)
- Value::Glob { no_expand, .. } if !*no_expand => expand_ndots(expand_tilde(&*name_str)),
+ Value::Glob { no_expand, .. } if !*no_expand => {
+ expand_ndots_safe(expand_tilde(&*name_str))
+ }
  _ => Path::new(&*name_str).to_owned(),
  };
 
@@ -294,7 +296,7 @@ fn expand_glob(
  // For an argument that doesn't include the GLOB_CHARS, just do the `expand_tilde`
  // and `expand_ndots` expansion
  if !arg.contains(GLOB_CHARS) {
- let path = expand_ndots(expand_tilde(arg));
+ let path = expand_ndots_safe(expand_tilde(arg));
  return Ok(vec![path.into()]);
  }
 
@@ -582,6 +584,21 @@ fn escape_cmd_argument(arg: &Spanned<OsString>) -> Result<Cow<'_, OsStr>, ShellE
  }
 }
 
+/// Expand ndots, but only if it looks like it probably contains them, because there is some lossy
+/// path normalization that happens.
+fn expand_ndots_safe(path: impl AsRef<Path>) -> PathBuf {
+ let string = path.as_ref().to_string_lossy();
+
+ // Use ndots if it contains at least `...`, since that's the minimum trigger point, and don't
+ // use it if it contains :https://, because that looks like a URL scheme and the path normalization
+ // will mess with that.
+ if string.contains("...") && !string.contains(":https://") {
+ expand_ndots(path)
+ } else {
+ path.as_ref().to_owned()
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;
@@ -610,7 +627,7 @@ mod test {
  assert_eq!(actual, expected);
 
  let actual = expand_glob("./a.txt", cwd, Span::unknown(), &None).unwrap();
- let expected: Vec<OsString> = vec![Path::new(".").join("a.txt").into()];
+ let expected = &["./a.txt"];
  assert_eq!(actual, expected);
 
  let actual = expand_glob("[*.txt", cwd, Span::unknown(), &None).unwrap();

crates/nu-command/tests/commands/run_external.rs

@@ -229,6 +229,38 @@ fn external_command_escape_args() {
  })
 }
 
+#[test]
+fn external_command_ndots_args() {
+ let actual = nu!(r#"
+ nu --testbin cococo foo/. foo/.. foo/... foo/./bar foo/../bar foo/.../bar ./bar ../bar .../bar
+ "#);
+
+ assert_eq!(
+ actual.out,
+ if cfg!(windows) {
+ // Windows is a bit weird right now, where if ndots has to fix something it's going to
+ // change everything to backslashes too. Would be good to fix that
+ r"foo/. foo/.. foo\..\.. foo/./bar foo/../bar foo\..\..\bar ./bar ../bar ..\..\bar"
+ } else {
+ r"foo/. foo/.. foo/../.. foo/./bar foo/../bar foo/../../bar ./bar ../bar ../../bar"
+ }
+ );
+}
+
+#[test]
+fn external_command_url_args() {
+ // If ndots is not handled correctly, we can lose the double forward slashes that are needed
+ // here
+ let actual = nu!(r#"
+ nu --testbin cococo http:https://example.com http:https://example.com/.../foo //foo
+ "#);
+
+ assert_eq!(
+ actual.out,
+ "http:https://example.com http:https://example.com/.../foo //foo"
+ );
+}
+
 #[test]
 #[cfg_attr(
  not(target_os = "linux"),