Only include stable lints in `rustdoc::all` group

Including unstable lints in the lint group produces unintuitive behavior
on stable (see #106289). Meanwhile, if we only included unstable lints
on nightly and not on stable, we could end up with confusing bugs that
were hard to compare across versions of Rust that lacked code changes.

I think that only including stable lints in `rustdoc::all`, no matter
the release channel, is the most intuitive option. Users can then
control unstable lints individually, which is reasonable since they have
to enable the feature gates individually anyway.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/librustdoc/lint.rs b/src/librustdoc/lint.rs
index 3aad97bc296..6d289eb996d 100644
--- a/src/librustdoc/lint.rs
+++ b/src/librustdoc/lint.rs
@@ -194,7 +194,11 @@ pub(crate) fn register_lints(_sess: &Session, lint_store: &mut LintStore) {
         true,
         "rustdoc::all",
         Some("rustdoc"),
-        RUSTDOC_LINTS.iter().map(|&lint| LintId::of(lint)).collect(),
+        RUSTDOC_LINTS
+            .iter()
+            .filter(|lint| lint.feature_gate.is_none()) // only include stable lints
+            .map(|&lint| LintId::of(lint))
+            .collect(),
     );
     for lint in &*RUSTDOC_LINTS {
         let name = lint.name_lower();