yoda: gate clipboard_x11 behind an opt-in feature

Upstream pulled clipboard_x11 unconditionally on unix, which drags
x11rb + x11rb-protocol and ~500 symbols of X11 clipboard code into
every Wayland-only iced build. Add an x11 feature (default-on for
compat) that gates:
- the clipboard_x11 workspace dep (now optional)
- `pub use clipboard_x11 as x11` re-export
- the Clipboard::X11 enum variant
- every match arm that handles it
- the fallback branch in `unsafe fn connect` (returns a helpful
  error when called with a non-Wayland display handle)

Wayland-only builds set `window_clipboard = { ..., default-features = false, features = ["wayland"] }` and skip the x11 backend entirely.

Cargo.toml

@@ -11,6 +11,16 @@ readme = "README.md"
 keywords = ["clipboard", "window", "ui", "gui", "raw-window-handle"]
 categories = ["gui"]
 
+[features]
+# Yoda: put the unix clipboard backends behind opt-in features. Upstream
+# pulled both X11 + Wayland unconditionally on unix — pure bloat for
+# Wayland-only builds (clipboard_x11 pulls x11rb + its protocol machinery).
+# Default keeps both enabled to preserve upstream behaviour; yoda consumers
+# pass default-features=false + "wayland" at the dep declaration.
+default = ["x11", "wayland"]
+x11 = ["dep:clipboard_x11"]
+wayland = ["dep:clipboard_wayland"]
+
 [dependencies]
 raw-window-handle = { version = "0.6", features = ["std"] }
 thiserror = "1.0"
@@ -24,8 +34,8 @@ clipboard-win = { version = "5.0", features = ["std"] }
 clipboard_macos = { version = "0.1", path = "./macos" }
 
 [target.'cfg(all(unix, not(any(target_os="macos", target_os="android", target_os="emscripten", target_os="ios", target_os="redox"))))'.dependencies]
-clipboard_x11 = { version = "0.4.2", path = "./x11" }
-clipboard_wayland = { version = "0.2.2", path = "./wayland" }
+clipboard_x11 = { version = "0.4.2", path = "./x11", optional = true }
+clipboard_wayland = { version = "0.2.2", path = "./wayland", optional = true }
 
 [dev-dependencies]
 rand = "0.8"

src/platform/linux.rs

@@ -11,10 +11,12 @@ use std::{borrow::Cow, error::Error, sync::Arc};
 use wayland::DndSender;
 
 pub use clipboard_wayland as wayland;
+#[cfg(feature = "x11")]
 pub use clipboard_x11 as x11;
 
 pub enum Clipboard {
     Wayland(wayland::Clipboard),
+    #[cfg(feature = "x11")]
     X11(x11::Clipboard),
 }
 
@@ -22,6 +24,7 @@ impl ClipboardProvider for Clipboard {
     fn read(&self) -> Result<String, Box<dyn Error>> {
         match self {
             Clipboard::Wayland(c) => c.read(),
+            #[cfg(feature = "x11")]
             Clipboard::X11(c) => c.read().map_err(Box::from),
         }
     }
@@ -29,6 +32,7 @@ impl ClipboardProvider for Clipboard {
     fn write(&mut self, contents: String) -> Result<(), Box<dyn Error>> {
         match self {
             Clipboard::Wayland(c) => c.write(contents),
+            #[cfg(feature = "x11")]
             Clipboard::X11(c) => c.write(contents).map_err(Box::from),
         }
     }
@@ -36,6 +40,7 @@ impl ClipboardProvider for Clipboard {
     fn read_primary(&self) -> Option<Result<String, Box<dyn Error>>> {
         match self {
             Clipboard::Wayland(c) => Some(c.read_primary()),
+            #[cfg(feature = "x11")]
             Clipboard::X11(c) => Some(c.read_primary().map_err(Box::from)),
         }
     }
@@ -46,6 +51,7 @@ impl ClipboardProvider for Clipboard {
     ) -> Option<Result<(), Box<dyn Error>>> {
         match self {
             Clipboard::Wayland(c) => Some(c.write_primary(contents)),
+            #[cfg(feature = "x11")]
             Clipboard::X11(c) => {
                 Some(c.write_primary(contents).map_err(Box::from))
             }
@@ -61,6 +67,7 @@ impl ClipboardProvider for Clipboard {
                 let ret = c.read_data::<ClipboardLoadData<T>>();
                 Some(ret.map(|ret| ret.0))
             }
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -76,6 +83,7 @@ impl ClipboardProvider for Clipboard {
             Clipboard::Wayland(c) => {
                 Some(c.write_data::<ClipboardStoreData<T>>(contents))
             }
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -89,6 +97,7 @@ impl ClipboardProvider for Clipboard {
                 let ret = c.read_primary_data::<ClipboardLoadData<T>>();
                 Some(ret.map(|ret| ret.0))
             }
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -99,6 +108,7 @@ impl ClipboardProvider for Clipboard {
     ) -> Option<Result<(Vec<u8>, String), Box<dyn Error>>> {
         match self {
             Clipboard::Wayland(c) => Some(c.read_primary_raw(allowed)),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -109,6 +119,7 @@ impl ClipboardProvider for Clipboard {
     ) -> Option<Result<(Vec<u8>, String), Box<dyn Error>>> {
         match self {
             Clipboard::Wayland(c) => Some(c.read_raw(allowed)),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -124,6 +135,7 @@ impl ClipboardProvider for Clipboard {
             Clipboard::Wayland(c) => {
                 Some(c.write_primary_data::<ClipboardStoreData<T>>(contents))
             }
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => None,
         }
     }
@@ -136,6 +148,7 @@ impl DndProvider for Clipboard {
     ) {
         match self {
             Clipboard::Wayland(c) => c.init_dnd(DndSender(Arc::from(tx))),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => {}
         }
     }
@@ -156,6 +169,7 @@ impl DndProvider for Clipboard {
                 content,
                 actions,
             ),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => {}
         }
     }
@@ -163,6 +177,7 @@ impl DndProvider for Clipboard {
     fn end_dnd(&self) {
         match self {
             Clipboard::Wayland(c) => c.end_dnd(),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => {}
         }
     }
@@ -176,6 +191,7 @@ impl DndProvider for Clipboard {
             Clipboard::Wayland(c) => {
                 c.register_dnd_destination(surface, rectangles)
             }
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => {}
         }
     }
@@ -183,6 +199,7 @@ impl DndProvider for Clipboard {
     fn set_action(&self, action: DndAction) {
         match self {
             Clipboard::Wayland(c) => c.set_action(action),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => {}
         }
     }
@@ -193,6 +210,7 @@ impl DndProvider for Clipboard {
     ) -> std::io::Result<D> {
         match self {
             Clipboard::Wayland(c) => c.peek_offer::<D>(mime_type),
+            #[cfg(feature = "x11")]
             Clipboard::X11(_) => Err(std::io::Error::new(
                 std::io::ErrorKind::Other,
                 "DnD not supported",
@@ -208,7 +226,15 @@ pub unsafe fn connect<W: HasDisplayHandle + ?Sized>(
         RawDisplayHandle::Wayland(handle) => Clipboard::Wayland(
             wayland::Clipboard::connect(handle.display.as_ptr()),
         ) as _,
+        #[cfg(feature = "x11")]
         _ => Clipboard::X11(x11::Clipboard::connect()?) as _,
+        #[cfg(not(feature = "x11"))]
+        _ => {
+            return Err(Box::from(
+                "Yoda window_clipboard: X11 feature disabled; \
+                 non-Wayland display handles are not supported",
+            ))
+        }
     };
 
     Ok(clipboard)