cursor: Add missing Send + Sync bound on callback

This had broken the API by making `CursorTheme` not `Send`/`Sync`, as it
had been before.

wayland-cursor/CHANGELOG.md

@@ -2,6 +2,16 @@
 
 ## Unreleased
 
+## 0.31.3 -- 2024-05-30
+
+#### Bugfixes
+- Add `Send + Sync` bounds to fallback callback
+
+## 0.31.2 -- 2024-05-30
+
+### Additions
+- Add `set_fallback` method
+
 ## 0.31.1 -- 2024-01-29
 
 - Dropped `nix` dependency in favor or `rustix`

wayland-cursor/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "wayland-cursor"
-version = "0.31.2"
+version = "0.31.3"
 documentation = "https://docs.rs/wayland-cursor/"
 repository = "https://github.com/smithay/wayland-rs"
 authors = ["Elinor Berger <[email protected]>"]

wayland-cursor/src/lib.rs

@@ -86,14 +86,14 @@ pub struct CursorTheme {
     fallback: Option<FallBack>,
 }
 
-type FallBackInner = Box<dyn Fn(&str, u32) -> Option<Cow<'static, [u8]>>>;
+type FallBackInner = Box<dyn Fn(&str, u32) -> Option<Cow<'static, [u8]>> + Send + Sync>;
 
 struct FallBack(FallBackInner);
 
 impl FallBack {
     fn new<F>(fallback: F) -> Self
     where
-        F: Fn(&str, u32) -> Option<Cow<'static, [u8]>> + 'static,
+        F: Fn(&str, u32) -> Option<Cow<'static, [u8]>> + Send + Sync + 'static,
     {
         Self(Box::new(fallback))
     }
@@ -232,7 +232,7 @@ impl CursorTheme {
     /// ```
     pub fn set_fallback<F>(&mut self, fallback: F)
     where
-        F: Fn(&str, u32) -> Option<Cow<'static, [u8]>> + 'static,
+        F: Fn(&str, u32) -> Option<Cow<'static, [u8]>> + Send + Sync + 'static,
     {
         self.fallback = Some(FallBack::new(fallback))
     }