form method 'reset' can't work well with none-empty preview

[davidhsing]

Steps to reproduce the issue

1. Setup a form with a 'file-loading' input and a reset button.
2. Set the fileinput element with 'uploadUrl' option. (This will show a drop zone title like 'Drag files here...')
3. Choose a picture whatever.
4. Click the form's 'reset' button.

Expected behavior and actual behavior

When I follow those steps, I see...
The drop zone title has gone.

I was expecting...
It works well.

Environment

Browsers

• [] Google Chrome

Operating System

• [] Windows

Libraries

• jQuery version: 2.1.4
• bootstrap-fileinput version: 4.4.2

My Solution

The problem was caused by the 'bootstrap-fileinput.js' at line 3556 & 3557, which is
"
3556: self._setFileDropZoneTitle();
3557: self.clearStack();
"
Since the first function will check the "self.getFileStack().length > 0" condition, which will be always true, and it will be dealed with the next function of line 3557.
So, exchange the two lines, the fileinput works very well.