Filechooser: Use full path

[s0h3ck]

Description

When the path attribute is set, the full path is duplicated. Here is an example:
https://github.com/kivy/kivy/blob/master/kivy/uix/filechooser.py#L615

self.path = ./data/images/
entry.path = data/images/minecraft/skeleton.png

Example of the problem

The problem is with join. See the example here:

from os.path import abspath
print(abspath(join('./data/images/', 'data/images/minecraft/skeleton.png')))
# /home/s0h3ck/data/images/data/images/minecraft/skeleton.png
print(abspath(join('./data/images/', '/home/s0h3ck/data/images/minecraft/skeleton.png')))
# /home/s0h3ck/data/images/minecraft/skeleton.png

Suggestions

First

self.selection = abspath(entry.path)
https://github.com/kivy/kivy/blob/master/kivy/uix/filechooser.py#L615

Second

https://github.com/kivy/kivy/blob/master/kivy/uix/filechooser.py#L690
self.path = abspath(self.path)

Information

I applied the second suggestion because I don't know if the first suggestion can break something. on Windows or MacOS. The first would be better for performance because the second is called more than once.

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[Zen-CODE]

Nice, thanks. I struggled to reproduce this. Setting the path to a relative path was the trick. It crashes on selection, and this fixes it. Thanks +1

[Zen-CODE]

Setting the path on initialization to a relative path crashes the filechooser on selection. This fixes that problem.

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