Re: fontification loop

[Andreas Seltenreich]

martin rudalics <address@hidden> writes:

>> I just caught Emacs hogging the CPU with endless
>> redisplay/fontification.  The following code triggers it for me:
>>
[...]
> I tried this with emacs -Q and it left point at the end of line 178
> displaying baz with the "z" invisible.  No redisplay or fontification
> problems seen, but my build is older than yours.

I just tried it with older builds I had lying around: It also happens
with a build from 2006-08-23, but not with one from 2006-07-06.

> Does it happen when you try emacs -Q too?

Yes.  Also, -nw shows the same symptoms.

I've examined this a bit more, and it looks like
fontification-functions are called over and over with the same
argument despite the `fontified' property being t for the whole
buffer.

(trace-function-background 'jit-lock-function)

--8<---------------cut here---------------start------------->8---
======================================================================
1 -> jit-lock-function: start=1
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=709
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=618
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=709
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=614
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=709
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=709
1 <- jit-lock-function: nil
======================================================================
1 -> jit-lock-function: start=709
1 <- jit-lock-function: nil
[80,000 lines stripped]
--8<---------------cut here---------------end--------------->8---

Thanks,
andreas