Drag-splitting started by a double-click collects all matching items instead of distributing them

1.Summary

If the player picks up a stack and then, within the 250 ms double-click window, presses-and-holds the left button again on the same slot to start a left-drag (quick-craft), releasing the button does not distribute the items. The client instead sends a PICKUP_ALL ("collect all") click: every matching item in the open GUI — including the ones that were visually being distributed, plus all other stacks of the same type that were never touched — is consolidated onto the cursor stack. The dragged-over slots stay empty. The even distribution the player sees while dragging is a client-side preview only; the drag is never transmitted to the server.(Confirmed reproducible in every version from 1.8.9 through 26.3.While the video demonstration was recorded on Lunar Client,the issue also reproduces on the vanilla client.)

2. Steps to Reproduce

1. Open any container GUI (chest, crafting table, player inventory screen, etc.).

2. Arrange several stacks of the same item type: one stack of ≥2 items in a slot you will pick up, at least one additional stack of the same type elsewhere (to make the "collect all" effect obvious), and ≥2 empty slots to drag over.

3. Left-click the stack to pick it up (press #1).

4. Within 250 ms, on the same slot, press and hold the left button again (press #2). This press simultaneously starts a left-drag (quick-craft) and qualifies as the second half of a double-click.

5. While holding the button, sweep the cursor over the ≥2 empty target slots. Observe the GUI showing the items being distributed evenly (one per slot, remainder in yellow on the cursor).

6. Release the left button while hovering over any slot.

Expected: Each dragged-over slot receives its even share; remainder stays on the cursor; other stacks untouched.

Actual: Nothing is distributed. All matching items in the whole GUI are merged onto the cursor; the dragged-over slots remain empty.