[Bug Report] el-select requires 2 tabs when using multiple and filterable

[ChuckFields]

Element UI version

2.4.1

OS/Browsers version

Windows 10 / Chrome - latest

Vue version

2.5.16

Reproduction Link

https://jsfiddle.net/9s2evjtp/

Steps to reproduce

Focus in the first el-input.
Tab to the first el-select.
Tab to the second el-select.
Hit tab.

What is Expected?

The focus to jump to the last el-input.

What is actually happening?

The focus remains in the el-select until you hit tab once more.

[ghost]

Also, it requires 2 clicks to open popper if you are focused on other input. Not always though.

[badpunman]

Also, it requires 2 clicks to open popper if you are focused on other input. Not always though.

iumag@29c7cc2
this seems to fix the issue. Issue occurs with just filterable attribute alone.