zed/crates/language
Kirill Bulatov 8276687148
Use proper rules for merging language server settings (#61546)
Closes https://github.com/zed-industries/zed/issues/61524

https://github.com/zed-industries/zed/issues/60763 was a bogus issue:
the semantic of root `language_settings` is the **default settings for
all languages**, not a "magic string that gets applied when an `!x`
exclusion is mentioned there".

Thus, reverts https://github.com/zed-industries/zed/pull/60984 and
redoes https://github.com/zed-industries/zed/pull/60000 in a correct
way: more custom settings replace less custom ones, same applies to the
language server settings.
Instead of doing some odd `!x` manipulations, the right fix is to remove
the old state as

```diff
 impl merge_from::MergeFrom for AllLanguageSettingsContent {
     fn merge_from(&mut self, other: &Self) {
         ...
         self.defaults.merge_from(&other.defaults);
         for language_settings in self.languages.0.values_mut() {
+            let language_servers = language_settings.language_servers.take();
             language_settings.merge_from(&other.defaults);
+            language_settings.language_servers = language_servers;
         }

         for (language_name, user_language_settings) in &other.languages.0 {
             if let Some(existing) = self.languages.0.get_mut(language_name) {
                 existing.merge_from(&user_language_settings);
             } else {
                 let mut new_settings = self.defaults.clone();
+                new_settings.language_servers = None;
                 new_settings.merge_from(&user_language_settings);
```

After the final override is determined, `...` is expanded and `!x`
entries are removed from the final list.

Project settings override user settings, so it's possible that a certain
language server is disabled by the user and re-enabled in the project:
worktree trust mechanism is supposed to mitigate the security issues.

More tests were added to cover all the cases.

Release Notes:

- Fixed project settings not re-enabling language servers
2026-07-24 08:32:03 +00:00
..
benches Extract language_core and grammars crates from language (#52238) 2026-03-25 23:41:09 +00:00
src Use proper rules for merging language server settings (#61546) 2026-07-24 08:32:03 +00:00
build.rs
Cargo.toml language: Fix JSON rainbow bracket colors across chunks (#60741) 2026-07-23 08:41:26 +00:00
LICENSE-GPL