A shift-click during a drag on a mod menu type only ends the drag

On a mod's own menu type the drag lives in the connection's machine menu,
not in the hub menu's drag, so lan_mod_quick_move passed the click to the
mods. Leave it to lan_machine_click, which resets the quick craft as
AbstractContainerMenu.doClick does.

Fixes #6907.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/horizon-client/src/game/native_quick_move.rs

@@ -126,6 +126,17 @@ impl Game<'_> {
         }
         let size = menu.size;
         let window = menu.window;
+        // A mod menu type keeps its drag in the connection's machine menu
+        // (`lan_machine_click`), not in `menu.drag`: a shift-click during it
+        // goes there too, to only end the drag.
+        if host
+            .play
+            .get(&conn)
+            .and_then(|play| play.crafting.machine.as_ref())
+            .is_some_and(|(w, m)| *w == window && m.quick_crafting())
+        {
+            return false;
+        }
         if !matches!(
             self.world.block_entities.get(&pos),
             Some(BlockEntity::Mod(m)) if !m.id.is_empty()

crates/horizon-client/src/menu.rs

@@ -2545,6 +2545,12 @@ impl Menu {
         }
     }
 
+    /// Whether a drag (quick craft) is in progress (`quickcraftStatus != 0`):
+    /// the next click other than a quick craft only ends it.
+    pub fn quick_crafting(&self) -> bool {
+        self.quick_status != 0
+    }
+
     fn reset_quick_craft(&mut self) {
         self.quick_status = 0;
         self.quick_slots.clear();
@@ -3668,6 +3674,27 @@ pub(crate) mod tests {
         });
     }
 
+    /// #6907: a drag in progress is seen from outside the menu, and a
+    /// quick move during it only ends the drag (`doClick`'s resetQuickCraft).
+    #[test]
+    fn a_quick_move_during_a_drag_only_ends_it() {
+        with_menu(Kind::Chest(3), |env, menu| {
+            menu.creative = false;
+            menu.set_slot(env, 27, stack("dirt", 10));
+            menu.carried = stack("cobblestone", 64);
+            assert!(!menu.quick_crafting());
+            // Start a left drag, then drag across chest slot 0.
+            menu.click(env, -999, 0, Input::QuickCraft).unwrap();
+            menu.click(env, 0, 1, Input::QuickCraft).unwrap();
+            assert!(menu.quick_crafting());
+            // A shift-click now moves nothing and ends the drag.
+            menu.click(env, 27, 0, Input::QuickMove).unwrap();
+            assert!(!menu.quick_crafting());
+            assert_eq!(menu.slot(27).map(|s| s.count), Some(10));
+            assert_eq!(menu.slot(0), None);
+        });
+    }
+
     /// #1832: a potion taken from the creative inventory and put in the
     /// hotbar keeps its `PotionContents` (the brew), as vanilla's
     /// `PotionContents.createItemStack` builds it: the item tab's stack is