Forward compatibility: highlight unknown `type -w` outputs correctly

[danielshahaf]

#298 (comment) (channeling @m0vie) points out that the catchall branch of the type -w output checker is not forward-compatible: if type -w exited zero and emitted an unrecognised string, the code won't handle that.

The fix would probably be to make line 333 check for $? == 0 and do $something in that case.

(Labelling "Regression" since there's no separate "Forward compatibility" label)

[danielshahaf]

Fixed by 12b879c. However:

Release blocker: decide the fallback order that https://github.com/zsh-users/zsh-syntax-highlighting/blob/master/highlighters/main/main-highlighter.zsh#L456-L457 should use.

[danielshahaf]

That link wasn't properly pegged; it was presumably meant to refer to

zsh-syntax-highlighting/highlighters/main/main-highlighter.zsh

Lines 456 to 457 in 12b879c

	*) _zsh_highlight_main_add_region_highlight commandtypefromthefuture-$res
	already_added=1

.

[danielshahaf]

Added commit with proposed fix. @phy1729 and I are +1 on the fallback order. The docs may need tweaking.

[danielshahaf]

Added 94e505a to https://github.com/danielshahaf/zsh-syntax-highlighting/tree/i316-v1.

[danielshahaf]

Squashed that as master...danielshahaf:i316-v2.

[danielshahaf]

@phy1729 WDYT?

[danielshahaf]

command function etc should fall back to arg0.

[danielshahaf]

command function etc should fall back to arg0.

Rough draft: master...danielshahaf:WIP-style-tree-fallback-v0

This is basically the "style tree" idea.