Re: Different fontification in temp buffer

[Daniele Nicolodi <daniele@grinta.net>]

On 19/01/2019 17:48, Daniele Nicolodi wrote:
> Hello,
> 
> I'm hacking on a minor mode and I'm writing unit tests for the
> fontification feature. I am encountering a strange issue: the
> fontification is different if execute in a temp buffer or in a regular
> buffer. In particular:
> 
>   (with-temp-buffer
>     (insert string)
>     (fundamental-mode)
>     (beancount-mode)
>     (font-lock-ensure)
>     (buffer-string))
> 
> and
> 
>   (with-current-buffer (generate-new-buffer "*test*")
>     (insert string)
>     (fundamental-mode)
>     (beancount-mode)
>     (font-lock-ensure)
>     (buffer-string))
> 
> strangely result in two different results. Why is it so?

Investigating further, the difference between the two cases is that
with-temp-buffer creates a buffer that does not keep undo information.
Surely enough, if I modify the second code to do the same (using a
buffer name starting with a space character) I obtain the same behavior.

What's left to understand is why this results in two different syntax
table being applied to the buffer.

Cheers,
Dan