Autocomplete highlights wrong search results when they appear under the cursor

Description:

If the cursor is near the bottom of the channel window, when you @ search to autocomplete it will automatically and incorrectly highlight whatever happens to be under the cursor which is almost never what you intend.

Steps to reproduce:

1. position your mouse cursor just above the message box
2. type @ and optionally some search chars
3. the autocomplete pops up in the same region as the mouse cursor

Expected behavior:

When you are typing the search autocomplete should appear under the cursor and the first item selected. The focused item should only be affected by keyboard navigation, ie key down to select a result to select it. If the mouse cursor is moved then, and only then, should that result in a highlight of an autocomplete item. If you then swap back to the keyboard and type more then the mouse position should be ignored again.

Actual behavior:

The item under the cursor is selected. If the cursor is positioned close to the bottom, and 5 records are shown in the popup, then it will select the 5th most useful result instead of defaulting to the 1st most useful result.

Server Setup Information:

• Version of Rocket.Chat Server: 0.73.2
• Operating System: linux 4.4.0-154-generic
• Deployment Method:
• Number of Running Instances:
• DB Replicaset Oplog:
• NodeJS Version:
• MongoDB Version:

Start by reproducing the autocomplete behavior in a channel near the bottom of the window, following the listed @-search steps with both mouse and keyboard input. Locate the autocomplete UI entry point responsible for hover selection and keyboard focus. Done means typing selects the first result, keyboard navigation changes selection, and mouse movement only affects the highlight after the pointer moves.