bug#32265: 26.1; yank-excluded-properties set to t triggers "Error in syntax_table logic for intervals <-" signal

[Eli Zaretskii <eliz@gnu.org>]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Tue, 31 Jul 2018 08:04:18 -0400
> Cc: 32265@debbugs.gnu.org
> 
> ../../src/intervals.c:371: Emacs fatal error: assertion failed: LENGTH (i) > 0
> 
> #0  terminate_due_to_signal (sig=6, backtrace_limit=2147483647) at ../../src/emacs.c:364
> #1  0x00000000006161d3 in die (msg=0x7795cd "LENGTH (i) > 0", file=0x7794f0 "../../src/intervals.c", 
>     line=371) at ../../src/alloc.c:7410
> #2  0x00000000006b51c4 in balance_an_interval (i=0x32e9d78) at ../../src/intervals.c:371
> #3  0x00000000006b54a4 in balance_possible_root_interval (interval=0x32e9d78)
>     at ../../src/intervals.c:420
> #4  0x00000000006b579e in split_interval_right (interval=0x32e9d78, offset=-1)
>     at ../../src/intervals.c:507

That offset=-1 there is already bogus, AFAIU.

> #5  0x00000000006bfe11 in set_text_properties_1 (start=make_number(8232), end=make_number(8474), 
>     properties=XIL(0), object=XIL(0x2ff57f5), i=0x32e9d78) at ../../src/textprop.c:1436
> #6  0x00000000006bfcad in set_text_properties (start=make_number(8232), end=make_number(8474), 
>     properties=XIL(0), object=XIL(0x2ff57f5), coherent_change_p=XIL(0xc090))
>     at ../../src/textprop.c:1397
> #7  0x00000000006bf9d6 in Fset_text_properties (start=make_number(8232), end=make_number(8474), 
>     properties=XIL(0), object=XIL(0)) at ../../src/textprop.c:1304
> #8  0x000000000063e4a6 in funcall_subr (subr=0xd81680 <Sset_text_properties>, numargs=3, 
>     args=0x7fffffff9f80) at ../../src/eval.c:2856
> (More stack frames follow...)
> 
> Lisp Backtrace:
> "set-text-properties" (0xffff9f80)
> "remove-yank-excluded-properties" (0xffffa4c8)
> "insert-for-yank-1" (0xffffa9d8)
> "insert-for-yank" (0xffffaea8)

I presume just calling set-text-properties with the same arguments
there doesn't trigger the problem?  If so, I think we need to
understand how come we got offset=-1 in frame #4.

Thanks.