language_selector: Improve lookup for language icons (#26376)

This PR fixes a rare case where icons could be missing in the language
selector.

Currently, whilst looking up an icon, all file suffixes starting with a
dot are filtered out. While this works fine for some languages, there
are some languages having only file suffixes starting with a dot, e.g.
the "Git Attributes" language provided from the "Git Firefly" extension.
This results in no icon being displayed in the list, as shown in the
screenshots below.

To solve this, we can just simply remove the check for this special case
as well as the construction of an artificial file name in the code, as
both are not needed. A simple path just consisting of the extension is
sufficient, as we currently do not differentiate between file names and
file suffixes during an icon lookup. see the relevant code below:


013a646799/crates/file_icons/src/file_icons.rs (L23-L52)

As the first lookup is directly done using the entire file name and then
checked against all suffixes, we actually do not have to construct an
artificial file name at all. Should that produce no match, we check for
a hidden file right after, so we do not have to filter hidden file names
out.

With this fix, nothing changes for "normal" file suffixes, for some
cases where languges provide entire file names as a path suffix, the
matching might improve, and for languages with only hidden associated
file names, the initially described issue is resolved.

I do believe the behavior of matching icons to languages could be
improved in general. Fowever, I do think this is beyond the scope of
this change.

| Current main | <img width="546" alt="main"
src="https://github.com/user-attachments/assets/5c3c9fdc-cadf-4e44-9667-2530374aa0d2"
/> |
| --- | --- |
| This PR |<img width="546" alt="PR"
src="https://github.com/user-attachments/assets/82e59108-e31f-4ca9-8bbd-b9fd2b34feb0"
/>|

Aditionally, in 4395f78fb2 I refactored
the code which acquires the label and icon for a match, since I found it
a bit hard to read initially. The majority of this diff comes from this
change. Should that not be wanted, I can revert that change.

Release Notes:

- Fixed a rare case where languages had no associated icon in the
language selector.

crates/language_selector/src/language_selector.rs

@@ -139,31 +139,27 @@ impl LanguageSelectorDelegate {
         let mut label = mat.string.clone();
         let buffer_language = self.buffer.read(cx).language();
         let need_icon = FileFinderSettings::get_global(cx).file_icons;
-        if let Some(buffer_language) = buffer_language {
-            let buffer_language_name = buffer_language.name();
-            if buffer_language_name.as_ref() == mat.string.as_str() {
-                label.push_str(" (current)");
-                let icon = need_icon
-                    .then(|| self.language_icon(&buffer_language.config().matcher, cx))
-                    .flatten();
-                return (label, icon);
-            }
-        }
 
-        if need_icon {
-            let language_name = LanguageName::new(mat.string.as_str());
-            match self
-                .language_registry
-                .available_language_for_name(language_name.as_ref())
-            {
-                Some(available_language) => {
-                    let icon = self.language_icon(available_language.matcher(), cx);
-                    (label, icon)
-                }
-                None => (label, None),
-            }
+        if let Some(buffer_language) = buffer_language
+            .filter(|buffer_language| buffer_language.name().as_ref() == mat.string.as_str())
+        {
+            label.push_str(" (current)");
+            let icon = need_icon
+                .then(|| self.language_icon(&buffer_language.config().matcher, cx))
+                .flatten();
+            (label, icon)
         } else {
-            (label, None)
+            let icon = need_icon
+                .then(|| {
+                    let language_name = LanguageName::new(mat.string.as_str());
+                    self.language_registry
+                        .available_language_for_name(language_name.as_ref())
+                        .and_then(|available_language| {
+                            self.language_icon(available_language.matcher(), cx)
+                        })
+                })
+                .flatten();
+            (label, icon)
         }
     }
 
@@ -171,13 +167,7 @@ impl LanguageSelectorDelegate {
         matcher
             .path_suffixes
             .iter()
-            .find_map(|extension| {
-                if extension.contains('.') {
-                    None
-                } else {
-                    FileIcons::get_icon(Path::new(&format!("file.{extension}")), cx)
-                }
-            })
+            .find_map(|extension| FileIcons::get_icon(Path::new(extension), cx))
             .map(Icon::from_path)
             .map(|icon| icon.color(Color::Muted))
     }