muhmuhten
commented
5 years ago An alternative would be to change the check instead of making b:hi_lasttick misleadingly named, which is more in line with the example in the documentation for b:changedtick.
My rationale for making the change this way is motivated by backward compatibility:
setl inde=FixedHtmlIndent()
func! FixedHtmlIndent()
let indent = HtmlIndent()
let b:hi_lasttick = b:changedtick - 1
return indent
endfuncPlaced in ~/.vim/after, this snippet monkey-patches the current version of the code to reuse state appropriately. Changing the assignment to b:hi_lasttick merely makes this code redundant, without breaking anything. It is comparatively difficult to write a script which will similarly smooth over the transition to b:hi_lasttick == b:changedtick.
brammool
Since 7.4.345 (2014-06-25), when the check was introduced, the html indent checks and sets b:hi_lasttick inconsistently:
This results in always recomputing a fresh state when the buffer has not changed, and very rarely may attempt to reuse a state after a buffer change. The only case where this is likely to be correct is when indenting the line immediately following a line whose indentation was just changed by the indenter, and can mistakenly reuse state when exactly one unrelated change has occurred in the meantime.
Always using a fresh state almost always gets the right indentation, but has noticeably awful O(n^2) performance when reindenting the entirety of HTML files with many lines.
The fix is trivial. However, I have not checked that the state update in HtmlIndent() is correct and matches the logic in FreshState(); it seems fine on casual inspection, but there may be bugs lurking there that haven't had a chance to manifest in the past four years because state reuse occurs so rarely.