fix orphaned pre-commit hook and missing returns after post_error

src/wayland/session_lock/lock.rs

@@ -75,8 +75,13 @@ where
                     return;
                 }
 
+                // Add pre-commit hook for updating surface state (before creating user data).
+                let commit_hook_id =
+                    compositor::add_pre_commit_hook::<D, _>(&surface, LockSurface::pre_commit_hook);
+
                 let data = ExtLockSurfaceUserData {
                     surface: surface.downgrade(),
+                    commit_hook_id,
                 };
                 let lock_surface = data_init.init(id, data);
 
@@ -97,9 +102,6 @@ where
                     }
                 });
 
-                // Add pre-commit hook for updating surface state.
-                compositor::add_pre_commit_hook::<D, _>(&surface, LockSurface::pre_commit_hook);
-
                 // Call compositor handler.
                 let lock_surface = LockSurface::new(surface, lock_surface);
                 state.new_surface(lock_surface.clone(), output);
@@ -111,6 +113,7 @@ where
                 // Ensure session is locked.
                 if !data.lock_status.load(Ordering::Relaxed) {
                     lock.post_error(Error::InvalidUnlock, "Session is not locked.");
+                    return;
                 }
 
                 state.lock_state().locked_outputs.clear();
@@ -120,6 +123,7 @@ where
                 // Ensure session is not locked.
                 if data.lock_status.load(Ordering::Relaxed) {
                     lock.post_error(Error::InvalidDestroy, "Cannot destroy session lock while locked.");
+                    return;
                 }
             }
             _ => unreachable!(),

src/wayland/session_lock/surface.rs

@@ -3,7 +3,7 @@
 use std::sync::Mutex;
 
 use crate::backend::renderer::buffer_dimensions;
-use crate::utils::{IsAlive, Logical, SERIAL_COUNTER, Serial, Size};
+use crate::utils::{IsAlive, Logical, SERIAL_COUNTER, Serial, Size, hook::HookId};
 use crate::wayland::compositor::{self, BufferAssignment, Cacheable, SurfaceAttributes};
 use crate::wayland::viewporter::{ViewportCachedState, ViewporterSurfaceState};
 use _session_lock::ext_session_lock_surface_v1::{Error, ExtSessionLockSurfaceV1, Request};
@@ -21,6 +21,7 @@ pub struct ExtLockSurfaceUserData {
     // `ExtSessionLockSurfaceV1`. So this reference needs to be weak to avoid a
     // cycle.
     pub(crate) surface: Weak<WlSurface>,
+    pub(crate) commit_hook_id: HookId,
 }
 
 impl<D> Dispatch<ExtSessionLockSurfaceV1, ExtLockSurfaceUserData, D> for SessionLockManagerState
@@ -71,6 +72,9 @@ where
         data: &ExtLockSurfaceUserData,
     ) {
         if let Ok(surface) = data.surface.upgrade() {
+            // Remove the pre-commit hook so orphaned commits don't trigger post_error
+            compositor::remove_pre_commit_hook(&surface, &data.commit_hook_id);
+
             compositor::with_states(&surface, |states| {
                 let mut attributes = states
                     .data_map