Upgrade rowan

Notably, new rowan comes with support for mutable syntax trees.

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/ide_assists/src/handlers/flip_trait_bound.rs b/crates/ide_assists/src/handlers/flip_trait_bound.rs
index d419d263e..a868aa43d 100644
--- a/crates/ide_assists/src/handlers/flip_trait_bound.rs
+++ b/crates/ide_assists/src/handlers/flip_trait_bound.rs
@@ -23,7 +23,7 @@ pub(crate) fn flip_trait_bound(acc: &mut Assists, ctx: &AssistContext) -> Option
     let plus = ctx.find_token_syntax_at_offset(T![+])?;
 
     // Make sure we're in a `TypeBoundList`
-    if ast::TypeBoundList::cast(plus.parent()).is_none() {
+    if ast::TypeBoundList::cast(plus.parent()?).is_none() {
         return None;
     }