bug#23221: 25.0.92; Crash in redisplay during isearch

[Andy Moreton <andrewjmoreton@gmail.com>]

On 05/04/2016 3:52 PM, Eli Zaretskii wrote:
>> From: Andy Moreton <amoreton@solarflare.com>
>> Date: Tue, 5 Apr 2016 14:28:55 +0100
>>
>> Emacs crashed during isearch in a Gnus summary buffer, after doing:
>>   - open a group
>>   - reload 2000 old articles ("/ o 2000 RET")
>> Attaching gdb showed the following backtrace (unfortunately I don't have the
>> session open any more).
>>
>> (gdb) bt
>> #0  0x000007fefd9831f3 in KERNELBASE!DebugBreak () from
>> C:\windows\system32\KernelBase.dll
>> #1  0x0000000400290224 in emacs_abort () at ../../src/w32fns.c:9794
>> #2  0x000000040012fc3b in terminate_due_to_signal (sig=0x16,
>> backtrace_limit=0x7fffffff) at ../../src/emacs.c:380
>> #3  0x00000004001c5462 in die (msg=0x4006b3280 <get_next_element+128>
>> "IT_BYTEPOS (*it) == CHAR_TO_BYTE (IT_CHARPOS (*it))", file=0x4006b1010
>> <DEFAULT_REHASH_SIZE+8> "../../src/xdisp.c", line=0x1d12) at
>> ../../src/alloc.c:7218
>> #4  0x0000000400043d79 in set_iterator_to_next (it=0x826840, reseat_p=0x1) at
>> ../../src/xdisp.c:7442
>> #5  0x0000000400049315 in move_it_in_display_line_to (it=0x826840,
>> to_charpos=0x1daff, to_x=0xffffffff, op=MOVE_TO_POS) at ../../src/xdisp.c:9012
>> #6  0x000000040004a669 in move_it_to (it=0x826840, to_charpos=0x1daff,
>> to_x=0xffffffff, to_y=0xffffffff, to_vpos=0xffffffff, op=0x8) at
>> ../../src/xdisp.c:9333
>
> Did you make local changes in the 25.0.92 sources?  The line numbers
> in the backtrace make no sense; I tried both the stock 25.0.92 sources
> and the current emacs-25 branch, and none matched.  What am I missing?

Strange. This was built from the emacs-25 branch without any local changes,
at commit a05fb21d73d2ca84dd7e5e7ee931931048ecddba. The line numbers look to 
match the backtrace here - what is mismatched for you ?

     AndyM