[BUG] misaligned-pointer-use memtodest() src/expand.c:964:17

Dear Dash maintainers,

I encountered a bug in Dash in commit f8aaaa (Also the behaviour repeats on
0.5.13 version of Dash) and would like to report
it. The details are provided below.

expand.c:964:17: runtime error: load of misaligned address 0x608e5f3d3fa3
for type 'uint64_t' (aka 'unsigned long'), which requires 8 byte alignment
0x608e5f3d3fa3: note: pointer points here
 00  20 00 04 64 61 73 68 2d  74 74 74 00 00 00 00 00  41 87 34 02 00 00 00
00  19 00 00 00 00 00 00
              ^
    #0 0x608e45209c1b in memtodest
/upstream/z/dash-0.5.13/src/expand.c:964:17
    #1 0x608e4520f17e in expmeta /upstream/z/dash-0.5.13/src/expand.c:1737:4
    #2 0x608e452052b9 in expandmeta
/upstream/z/dash-0.5.13/src/expand.c:1562:3
    #3 0x608e452027b2 in expandarg
/upstream/z/dash-0.5.13/src/expand.c:246:3
    #4 0x608e451fafdd in fill_arglist
/upstream/z/dash-0.5.13/src/eval.c:680:3
    #5 0x608e451f4e81 in evalcommand
/upstream/z/dash-0.5.13/src/eval.c:788:13
    #6 0x608e451f407c in evaltree /upstream/z/dash-0.5.13/src/eval.c:305:12
    #7 0x608e452201ac in cmdloop /upstream/z/dash-0.5.13/src/main.c:247:8
    #8 0x608e4521fe6e in main /upstream/z/dash-0.5.13/src/main.c:181:3
    #9 0x7566db7b9249 in __libc_start_call_main
csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    #10 0x7566db7b9304 in __libc_start_main csu/../csu/libc-start.c:360:3
    #11 0x608e451c2930 in _start (/upstream/z/dash-0.5.13/src/dash+0x42930)
(BuildId: f5787a810ed7cf088639c548c8ff13ea66dcb3e3)

SUMMARY: UndefinedBehaviorSanitizer: misaligned-pointer-use expand.c:964:17
Aborted (core dumped)

////////////////
My environment:
////////////////

Debian-12, x86-64, clang-19 compiler

/////////////////
Steps to reproduce:
/////////////////

$ aclocal && autoheader && automake --add-missing && autoconf
$ CC=clang CFLAGS=" -Wno-everything -fsanitize=undefined -g -O0"
./configure --disable-fnmatch --disable-lineno --disable-glob
$ make
$ cd src
$ ./dash < myfile.txt

//////////////////
Steps to get myfile.txt:
//////////////////

copy the text into file bs64.txt (between ==== and ======):
=====================================================================================
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Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3Nzc3
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b28gIiRAIgpwcmluAAAAQGZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZm
ZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmZmICdbJXNdXG4nIGZvbyAn
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=====================================================================================

Then do the action: base64 -d bs64.txt > myfile.txt
Or just take from attachments