bug#61298: Emacs 29.0.60: font-lock throws an args-out-of-range error with a long line.

[Eli Zaretskii]

> Date: Sun, 5 Feb 2023 14:54:35 +0000
> From: Alan Mackenzie <acm@muc.de>
> 
> Error: args-out-of-range (260028 260028)
>   mapbacktrace(#f(compiled-function (evald func args flags) #<bytecode 
> 0xdf8c26265ae87c7>))
>   debug-early-backtrace()
>   debug-early(error (args-out-of-range 260028 260028))  <===============
>   get-text-property(260028 font-lock-multiline)
>   font-lock-extend-region-multiline()
>   font-lock-default-fontify-region(1 260029 nil)
>   c-font-lock-fontify-region(1 1501 nil)
>   font-lock-fontify-region(1 1501)
>   #f(compiled-function (fun) #<bytecode 
> -0x156eee0f20909c83>)(font-lock-fontify-region)
>   run-hook-wrapped(#f(compiled-function (fun) #<bytecode 
> -0x156eee0f20909c83>) font-lock-fontify-region)
>   jit-lock--run-functions(1 1501)
>   jit-lock-fontify-now(1 1501)
>   jit-lock-function(1)
>   redisplay_internal\ \(C\ function\)()
> 
> This is clearly a bug.
> 
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> 
> Position 260028 is within the bounds of the buffer.  It would appear
> that the new-ish long-lines code has narrowed the buffer at some stage
> such that point-max is less than the end of the buffer.  I propose the
> following simple patch which fixes (or works around) this bug:

Fine with me, please install on the emacs-29 branch, and thanks.