never remove ~/.config/fish/fish_plugins when update/install

[lengyijun]

Follow #798

Partial fix #770 #790

[lengyijun]

in #798, fisher update removes fish_plugins, if fish_variables is broken.

With this pr, fisher update will not remove fish_plugins.
To fix the broken fish_variables, we can

fisher_path=(mktemp -d) fisher update
fisher update

[jimblue]

Just tested, the fix is working great !

[jorgebucaran]

The original code is saying that if _fisher_plugins is empty then it removes fish_plugins entirely to avoid leaving an empty plugins file behind.

Your proposal makes sense too, but I don't understand why we need it or how it relates to #796.

Can you clarify?

[lengyijun]

The original code is saying that if _fisher_plugins is empty then it removes fish_plugins entirely to avoid leaving an empty plugins file behind.

_fisher_plugins is empty doesn't mean fish_plugins file is empty.
_fisher_plugins is broken because of some accidents, for example, reset themes.
rm fish_plugins means we forget all plugins we used to install

[lengyijun]

796 should be a typo

[jorgebucaran]

@lengyijun
Do you mean there are cases where _fisher_plugins exists but fish_plugins does not, and that this only happens when _fisher_plugins is corrupted? If so, how does it get corrupted? If I can reproduce it, maybe we can prevent it.

[lengyijun]

how does it get corrupted

Not related to fisher.
fish_variables are removed to reset themes or reset environment variables

Most plugins don't rely on fish_variables.
I often remove fish_variables to reset everything

[lengyijun]

Another case where _fisher_plugins is broken but fish_plugins is not:

#790 (comment)

With this pr, fish_plugins is kept, that is important

[jorgebucaran]

Why are you messing with fish_variables again?

[lengyijun]

This isn't just my problem; many people have encountered this.