Bug#400771: Syntax highlighting causes Vim to hang

[Bram Moolenaar]

James -

> Bram,
> 
> Given the attached Makefile.am, it is possible to get Vim to hang in an
> infinite loop while doing syntax highlighting.  This seems to be
> dependant on the height of the Vim window as I am able to reproduce it
> with 'lines' set to certain values but not others.
> 
> vim -u NONE Makefile.am
> :set lines=3D24
> :set ruler  (not necessary but it is useful to see what line the cursor
>              is on when Vim starts to hang)
> :setf automake
> :syn on
> j   (press and hold until you reach the end of the file, using G will
>      not work)
> k   (press and hold until Vim hangs or you reach the top of the file.
>      If Vim did not hang, repeat the previous and current steps.  This
>      reliably hangs for me when the cursor gets to line 38)
> 
> You are able to press <C-c> to break out of the loop that Vim is in but
> moving around via j/k is more likely to cause the hang now.

I can reproduce it.  Looks like a hang or very slow pattern matching in
the syntax syncing stuff.  One more for the todo list.

- Bram

-- 
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       He was not at all afraid to be killed in nasty ways
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