On NetBSD/evbarm aarch64 (a Pinebook) with a -current of Sun Oct 27
2019, with userland from the `2019-10-26 20:40 UTC' HEAD snapshot, when
opening vi(1) with just `vi', and writing:

 | foo
 | bar
 | baz

...and then piping it to sort via `:%!sort' I have:

 parent-writer: received signal: Segmentation fault; core dumped.

...and the text is not sorted as expected.
Checking out src/external/bsd/nvi from CVS and then rebuilding it via
`make' here the corresponding debugging of the `.core':

 | % gdb -core vi.core ./vi
 | Reading symbols from ./vi...
 | Reading symbols from /tmp/src/external/bsd/nvi/usr.bin/nvi/vi.debug...
 | [New process 1]
 | Core was generated by `vi'.
 | Program terminated with signal SIGSEGV, Segmentation fault.
 | #0  0x000000020011e140 in ex_writefp (sp=sp@entry=0xf1ef4e281000, name=name@entry=0x20014b520 "filter", fp=0xf1ef4e48e730,
 |     fm=fm@entry=0xf1ef4e6db118, tm=tm@entry=0x0, nlno=nlno@entry=0x0, nch=nch@entry=0x0, silent=silent@entry=1)
 |     at /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:305
 | 305             gp = sp->gp;
 | (gdb) bt
 | #0  0x000000020011e140 in ex_writefp (sp=sp@entry=0xf1ef4e281000, name=name@entry=0x20014b520 "filter", fp=0xf1ef4e48e730,
 |     fm=fm@entry=0xf1ef4e6db118, tm=tm@entry=0x0, nlno=nlno@entry=0x0, nch=nch@entry=0x0, silent=silent@entry=1)
 |     at /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:305
 | #1  0x0000000200112004 in ex_filter (sp=sp@entry=0xf1ef4e281000, cmdp=cmdp@entry=0xf1ef4e6db050, fm=fm@entry=0xf1ef4e6db118, tm=0x0,
 |     tm@entry=0xf1ef4e6db128, rp=rp@entry=0xffffff9f3ab0, cmd=0x0, ftype=FILTER_BANG)
 |     at /tmp/src/external/bsd/nvi/dist/ex/ex_filter.c:238
 | #2  0x000000020010f76c in ex_bang (sp=0xf1ef4e281000, cmdp=0xf1ef4e6db050) at /tmp/src/external/bsd/nvi/dist/ex/ex_bang.c:162
 | #3  0x000000020010b494 in ex_cmd (sp=sp@entry=0xf1ef4e281000) at /tmp/src/external/bsd/nvi/dist/ex/ex.c:1391
 | #4  0x000000020012b978 in v_ex (sp=0xf1ef4e281000, vp=0xffffff9f3ca0) at /tmp/src/external/bsd/nvi/dist/vi/v_ex.c:418
 | #5  0x0000000200137620 in vi (spp=0xffffff9f3ec0) at /tmp/src/external/bsd/nvi/dist/vi/vi.c:248
 | #6  0x00000002001221d4 in editor (wp=wp@entry=0xf1ef4e6db000, argc=<optimized out>, argc@entry=1, argv=<optimized out>,
 |     argv@entry=0xffffff9f40e8) at /tmp/src/external/bsd/nvi/dist/common/main.c:136
 | #7  0x0000000200147238 in main (argc=1, argv=0xffffff9f40e8) at /tmp/src/external/bsd/nvi/dist/cl/cl_main.c:134
 | (gdb) set pagination off
 | (gdb) p *sp->gp
 | $1 = {
 |   progname = 0xffffff9f485a "vi",
 |   id = 2,
 |   dq = {
 |     tqh_first = 0xf1ef4e6db000,
 |     tqh_last = 0xf1ef4e6db000
 |   },
 |   hq = {
 |     tqh_first = 0x0,
 |     tqh_last = 0xf1ef4e299020
 |   },
 |   perl_interp = 0x0,
 |   tcl_interp = 0x0,
 |   cl_private = 0xf1ef4e28f000,
 |   tk_private = 0x0,
 |   frefq = {
 |     tqh_first = 0xf1ef4e279140,
 |     tqh_last = 0xf1ef4e2798c0
 |   },
 |   exfq = {
 |     tqh_first = 0xf1ef4e26e000,
 |     tqh_last = 0xf1ef4e26e0e0
 |   },
 |   opts = {{
 |       o_cur = {
 |         val = 136,
 |         str = 0x88 <error: Cannot access memory at address 0x88>
 |       },
 |       o_def = {
 |         val = 136,
 |         str = 0x88 <error: Cannot access memory at address 0x88>
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 32,
 |         str = 0x20 <error: Cannot access memory at address 0x20>
 |       },
 |       o_def = {
 |         val = 32,
 |         str = 0x20 <error: Cannot access memory at address 0x20>
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 0,
 |         str = 0x0
 |       },
 |       o_def = {
 |         val = 0,
 |         str = 0x0
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 266010115686408,
 |         str = 0xf1ef4e73c008 "screen"
 |       },
 |       o_def = {
 |         val = 266010115686880,
 |         str = 0xf1ef4e73c1e0 "screen"
 |       },
 |       flags = 0 '\000'
 |     }},
 |   msg = 0x0,
 |   msgq = {
 |     lh_first = 0x0
 |   },
 |   noprint = 1,
 |   c_option = 0x0,
 |   seqq = {
 |     lh_first = 0xf1ef4e1010f0
 |   },
 |   seqb = "\000@\001\b", '\000' <repeats 11 times>,
 |   cname = {{
 |       name = "^@\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^A\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^B\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^C\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^D\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^E\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^F\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^G\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^H\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^I\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^J\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^K\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^L\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^M\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^N\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^O\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^P\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Q\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^R\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^S\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^T\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^U\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^V\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^W\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^X\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Y\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Z\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^[\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^\\\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^]\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^^\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^_\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = " \000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "!\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "\"\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "#\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "$\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "%\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "&\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "'\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "(\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ")\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "*\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "+\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ",\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "-\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ".\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "/\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "0\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "1\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "2\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "3\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "4\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "5\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "6\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "7\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "8\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "9\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ":\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ";\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "<\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "=\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ">\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "?\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "@\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "A\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "B\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "C\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "D\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "E\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "F\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "G\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "H\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "I\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "J\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "K\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "L\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "M\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "N\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "O\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "P\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Q\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "R\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "S\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "T\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "U\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "V\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "W\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "X\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Y\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Z\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "[\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "\\\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "]\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "^\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "_\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "`\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "a\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "b\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "c\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "d\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "e\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "f\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "g\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "h\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "i\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "j\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "k\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "l\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "m\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "n\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "o\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "p\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "q\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "r\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "s\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "t\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "u\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "v\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "w\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "x\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "y\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "z\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "{\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "|\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "}\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "~\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "^?\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "\\x80",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x81",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x82",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x83",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x84",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x85",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x86",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x87",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x88",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x89",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8a",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8b",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8c",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8d",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8e",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8f",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x90",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x91",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x92",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x93",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x94",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x95",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x96",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x97",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x98",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x99",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9a",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9b",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9c",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9d",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9e",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9f",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa7",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa8",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa9",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xaa",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xab",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xac",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xad",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xae",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xaf",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb7",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb8",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb9",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xba",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbb",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbc",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbd",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbe",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbf",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc7",
 |       len = 4 '\004'
 |     }...},
 |   special_key = {K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_CNTRLD, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_VERASE, K_TAB, K_NL, K_NOTUSED, K_FORMFEED, K_CR, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_VLNEXT, K_CNTRLR, K_NOTUSED, K_CNTRLT, K_VKILL, K_VLNEXT, K_VWERASE, K_HEXCHAR, K_NOTUSED, K_CNTRLZ, K_ESCAPE, K_NOTUSED <repeats 13 times>, K_RIGHTPAREN, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_ZERO, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_COLON, K_NOTUSED <repeats 33 times>, K_BACKSLASH, K_NOTUSED, K_CARAT, K_NOTUSED <repeats 30 times>, K_RIGHTBRACE, K_NOTUSED, K_VERASE, K_NOTUSED <repeats 128 times>},
 |   flags = 64,
 |   scr_addstr = 0x200104e48 <cl_addstr>,
 |   scr_waddstr = 0x200104e40 <cl_waddstr>,
 |   scr_attr = 0x200104e50 <cl_attr>,
 |   scr_baud = 0x200104f88 <cl_baud>,
 |   scr_bell = 0x200105040 <cl_bell>,
 |   scr_busy = 0x200139670 <vs_busy>,
 |   scr_child = 0x0,
 |   scr_clrtoeol = 0x2001050c8 <cl_clrtoeol>,
 |   scr_cursor = 0x2001050f8 <cl_cursor>,
 |   scr_deleteln = 0x200105150 <cl_deleteln>,
 |   scr_discard = 0x200105248 <cl_discard>,
 |   scr_event = 0x200105fb0 <cl_event>,
 |   scr_ex_adjust = 0x2001052f8 <cl_ex_adjust>,
 |   scr_fmap = 0x200107420 <cl_fmap>,
 |   scr_keyval = 0x2001055c8 <cl_keyval>,
 |   scr_imctrl = 0x2001054e8 <cl_imctrl>,
 |   scr_insertln = 0x200105598 <cl_insertln>,
 |   scr_optchange = 0x200107588 <cl_optchange>,
 |   scr_move = 0x200105670 <cl_move>,
 |   scr_refresh = 0x2001056e8 <cl_refresh>,
 |   scr_rename = 0x2001058d0 <cl_rename>,
 |   scr_reply = 0x0,
 |   scr_screen = 0x200106788 <cl_screen>,
 |   scr_split = 0x2001059d0 <cl_split>,
 |   scr_suspend = 0x200105a50 <cl_suspend>,
 |   scr_usage = 0x200105c68 <cl_usage>,
 |   th_private = 0x0,
 |   run = 0x200123e20 <vi_nothread_run>,
 |   lock_init = 0x200123e38 <vi_nothread_lock>,
 |   lock_try = 0x200123e38 <vi_nothread_lock>,
 |   lock_unlock = 0x200123e38 <vi_nothread_lock>,
 |   lock_end = 0x200123e38 <vi_nothread_lock>
 | }
 | (gdb) p gp
 | $2 = <optimized out>
 | (gdb) disas/s
 | Dump of assembler code for function ex_writefp:
 | /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:
 | 293     {
 | 294             struct stat sb;
 | 295             GS *gp;
 | 296             u_long ccnt;                    /* XXX: can't print off_t portably. */
 | 297             db_recno_t fline, tline, lcnt;
 | 298             size_t len;
 | 299             int rval;
 | 300             const char *msg;
 | 301             CHAR_T *p;
 | 302             const char *f;
 | 303             size_t flen;
 | 304
 | 305             gp = sp->gp;
 |    0x000000020011e130 <+0>:     stp     x19, x20, [sp, #-320]!
 |    0x000000020011e134 <+4>:     mov     x19, x2
 |    0x000000020011e138 <+8>:     ldr     w20, [x3]
 |    0x000000020011e13c <+12>:    stp     x23, x24, [sp, #32]
 | => 0x000000020011e140 <+16>:    ldr     w23, [x4]
 |    0x000000020011e144 <+20>:    str     d8, [sp, #88]
 |    0x000000020011e148 <+24>:    fmov    d8, x1
 |    0x000000020011e14c <+28>:    ldr     x1, [x0, #48]
 |    0x000000020011e150 <+32>:    stp     x21, x22, [sp, #16]
 |    0x000000020011e154 <+36>:    stp     x27, x28, [sp, #64]
 |    0x000000020011e158 <+40>:    mov     x28, x0
 |    0x000000020011e15c <+44>:    mov     w27, w7
 |    0x000000020011e160 <+48>:    str     x30, [sp, #80]
 |    0x000000020011e164 <+52>:    str     x1, [sp, #104]
 | 
 | 306             fline = fm->lno;
 | 307             tline = tm->lno;
 | 308
 | 309             if (nlno != NULL) {
 |    0x000000020011e168 <+56>:    stp     x5, x6, [sp, #112]
 |    0x000000020011e16c <+60>:    cbz     x5, 0x20011e178 <ex_writefp+72>
 | 
 | [... more assembler dump output truncated ...]
 | End of assembler dump.
 | (gdb) info reg
 | x0             0xf1ef4e281000      266010110726144
 | x1             0x20014b520         8591291680
 | x2             0xf1ef4e48e730      266010112878384
 | x3             0xf1ef4e6db118      266010115289368
 | x4             0x0                 0
 | x5             0x0                 0
 | x6             0x0                 0
 | x7             0x1                 1
 | x8             0x3808              14344
 | x9             0x6                 6
 | x10            0x40                64
 | x11            0x3f                63
 | x12            0x3c7bd3923ca       4156408013770
 | x13            0x3c7bd3923cd       4156408013773
 | x14            0xf1ef4e6acd38      266010115099960
 | x15            0xf1ef4e48f378      266010112881528
 | x16            0xf1ef4e4817d8      266010112825304
 | x17            0xf1ef4e2e9c98      266010111155352
 | x18            0x1c10              7184
 | x19            0xf1ef4e48e730      266010112878384
 | x20            0x1                 1
 | x21            0xf1ef4e6db118      266010115289368
 | x22            0x0                 0
 | x23            0x0                 0
 | x24            0xf1ef4e48e698      266010112878232
 | x25            0xd44               3396
 | x26            0x0                 0
 | x27            0x0                 0
 | x28            0xf1ef4e6db050      266010115289168
 | x29            0x0                 0
 | x30            0x200112004         8591056900
 | sp             0xffffff9f3860      0xffffff9f3860
 | pc             0x20011e140         0x20011e140 <ex_writefp+16>
 | cpsr           0x80000000          [ EL=0 N ]
 | fpsr           0x0                 0
 | fpcr           0x0                 0
 | (gdb) p $x23
 | $3 = 0
 | (gdb) p $x24
 | $4 = 266010112878232
 | (gdb) p $sp
 | $5 = (void *) 0xffffff9f3860
 | (gdb) p $sp + 0x32
 | $6 = (void *) 0xffffff9f3892
 | (gdb) x/16x $sp + 0x32
 | 0xffffff9f3892: 0x00000000      0x00000000      0x00000000      0x38d00000
 | 0xffffff9f38a2: 0xffffff9f      0x382c0000      0xf1ef4e38      0x00040000
 | 0xffffff9f38b2: 0x00000000      0xea680000      0xf1ef4e69      0x000d0000
 | 0xffffff9f38c2: 0x00000000      0x00080000      0x00000000      0x00010000
 | (gdb) p $w23
 | $7 = 0
 | (gdb) p $x4
 | $8 = 0

Rebuilding with `-O0' (by default `-O2' is used) vi(1) doesn't crashes
when doing `:%!sort' and the text is piped and sorted as expected.

Trying to put a breakpoint on ex_writefp() and analyzing that:

 | % gdb -p 16366
 | Attaching to process 16366
 | Reading symbols from /tmp/src/external/bsd/nvi/usr.bin/nvi/./vi...
 | Reading symbols from /tmp/src/external/bsd/nvi/usr.bin/nvi/vi.debug...
 | Reading symbols from /usr/lib/libcurses.so.8...
 | Reading symbols from /usr/libdata/debug//usr/lib/libcurses.so.8.2.debug...
 | Reading symbols from /usr/lib/libterminfo.so.1...
 | Reading symbols from /usr/libdata/debug//usr/lib/libterminfo.so.1.0.debug...
 | Reading symbols from /usr/lib/libutil.so.7...
 | Reading symbols from /usr/libdata/debug//usr/lib/libutil.so.7.24.debug...
 | Reading symbols from /usr/lib/libc.so.12...
 | Reading symbols from /usr/libdata/debug//usr/lib/libc.so.12.214.debug...
 | Reading symbols from /usr/lib/i18n/libUTF8.so.5.0...
 | Reading symbols from /usr/libdata/debug//usr/lib/i18n/libUTF8.so.5.0.debug...
 | Reading symbols from /usr/libexec/ld.elf_so...
 | Reading symbols from /usr/libdata/debug//usr/libexec/ld.elf_so.debug...
 | [Switching to LWP 1 of process 16366]
 | 0x0000fceb4f6b85a0 in read () from /usr/lib/libc.so.12
 | (gdb) b ex_writefp
 | Breakpoint 1 at 0x20012d92c: file /tmp/src/external/bsd/nvi/dist/ex/ex_write.c, line 305.
 | (gdb) set pagination off
 | (gdb) set follow-fork-mode child
 | (gdb) set detach-on-fork off
 | (gdb) c
 | Continuing.
 | [Attaching after LWP 1 of process 16366 vfork to child LWP 1 of process 14304]
 | [New inferior 2 (process 14304)]
 | process 14304 is executing new program: /usr/pkg/bin/tcsh
 | [New process 14304]
 | [Attaching after process 14304 fork to child process 10597]
 | [New inferior 3 (process 10597)]
 | Reading symbols from /usr/libdata/debug/usr/lib/libterminfo.so.1.0.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libcrypt.so.1.0.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libc.so.12.214.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/i18n/libUTF8.so.5.0.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/i18n/libiconv_std.so.5.0.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/i18n/libmapper_none.so.5.0.debug...
 | Reading symbols from /usr/libdata/debug/libexec/ld.elf_so.debug...
 | [Inferior 3 (process 10597) exited normally]
 | (gdb) info inferiors
 |   Num  Description       Executable
 |   1    process 16366     /tmp/src/external/bsd/nvi/usr.bin/nvi/vi
 |   2    process 14304     /usr/pkg/bin/tcsh
 | * 3    <null>            /usr/pkg/bin/tcsh
 | (gdb) inferior 1
 | [Switching to inferior 1 [process 16366] (/tmp/src/external/bsd/nvi/usr.bin/nvi/vi)]
 | [Switching to thread 1.1 (LWP 1 of process 16366)]
 | #0  0x0000fceb4f705908 in __vfork14 () from /usr/lib/libc.so.12
 | (gdb) c
 | Continuing.
 | [New process 16366]
 | [Attaching after process 16366 fork to child process 15574]
 | [New inferior 4 (process 15574)]
 | Reading symbols from /tmp/src/external/bsd/nvi/usr.bin/nvi/vi.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libcurses.so.8.2.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libterminfo.so.1.0.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libutil.so.7.24.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/libc.so.12.214.debug...
 | Reading symbols from /usr/libdata/debug/usr/lib/i18n/libUTF8.so.5.0.debug...
 | Reading symbols from /usr/libdata/debug/libexec/ld.elf_so.debug...
 | [Switching to LWP 1 of process 15574]
 | 
 | Thread 4.1 "" hit Breakpoint 1, ex_writefp (sp=0xfceb4f657000, name=0x200175588 "filter", fp=0xfceb4f85e730, fm=0xfceb4fb0c118, tm=0xfceb4fb0c128, nlno=0x0, nch=0x0, silent=1) at /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:305
 | 305             gp = sp->gp;
 | (gdb) bt
 | #0  ex_writefp (sp=0xfceb4f657000, name=0x200175588 "filter", fp=0xfceb4f85e730, fm=0xfceb4fb0c118, tm=0xfceb4fb0c128, nlno=0x0, nch=0x0, silent=1) at /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:305
 | #1  0x000000020011ae4c in ex_filter (sp=0xfceb4f657000, cmdp=0xfceb4fb0c050, fm=0xfceb4fb0c118, tm=0xfceb4fb0c128, rp=0xffffffc5e210, cmd=0xfceb4f4dc000 L"sort", ftype=FILTER_BANG) at /tmp/src/external/bsd/nvi/dist/ex/ex_filter.c:238
 | #2  0x0000000200117204 in ex_bang (sp=0xfceb4f657000, cmdp=0xfceb4fb0c050) at /tmp/src/external/bsd/nvi/dist/ex/ex_bang.c:162
 | #3  0x00000002001106d8 in ex_cmd (sp=0xfceb4f657000) at /tmp/src/external/bsd/nvi/dist/ex/ex.c:1391
 | #4  0x0000000200143308 in v_ex (sp=0xfceb4f657000, vp=0xffffffc5e3b8) at /tmp/src/external/bsd/nvi/dist/vi/v_ex.c:418
 | #5  0x0000000200155b48 in vi (spp=0xffffffc5e690) at /tmp/src/external/bsd/nvi/dist/vi/vi.c:248
 | #6  0x0000000200134470 in editor (wp=0xfceb4fb0c000, argc=0, argv=0xffffffc5e800) at /tmp/src/external/bsd/nvi/dist/common/main.c:436
 | #7  0x0000000200107234 in main (argc=1, argv=0xffffffc5e7f8) at /tmp/src/external/bsd/nvi/dist/cl/cl_main.c:134
 | (gdb) p *sp->gp
 | $1 = {
 |   progname = 0xffffffc5ef6a "vi",
 |   id = 2,
 |   dq = {
 |     tqh_first = 0xfceb4fb0c000,
 |     tqh_last = 0xfceb4fb0c000
 |   },
 |   hq = {
 |     tqh_first = 0x0,
 |     tqh_last = 0xfceb4f669020
 |   },
 |   perl_interp = 0x0,
 |   tcl_interp = 0x0,
 |   cl_private = 0xfceb4faad000,
 |   tk_private = 0x0,
 |   frefq = {
 |     tqh_first = 0xfceb4f64f140,
 |     tqh_last = 0xfceb4f64f8c0
 |   },
 |   exfq = {
 |     tqh_first = 0xfceb4f644000,
 |     tqh_last = 0xfceb4f6440e0
 |   },
 |   opts = {{
 |       o_cur = {
 |         val = 136,
 |         str = 0x88 <error: Cannot access memory at address 0x88>
 |       },
 |       o_def = {
 |         val = 136,
 |         str = 0x88 <error: Cannot access memory at address 0x88>
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 32,
 |         str = 0x20 <error: Cannot access memory at address 0x20>
 |       },
 |       o_def = {
 |         val = 32,
 |         str = 0x20 <error: Cannot access memory at address 0x20>
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 0,
 |         str = 0x0
 |       },
 |       o_def = {
 |         val = 0,
 |         str = 0x0
 |       },
 |       flags = 0 '\000'
 |     }, {
 |       o_cur = {
 |         val = 278087584522248,
 |         str = 0xfceb4fb12008 "screen"
 |       },
 |       o_def = {
 |         val = 278087584522720,
 |         str = 0xfceb4fb121e0 "screen"
 |       },
 |       flags = 0 '\000'
 |     }},
 |   msg = 0x0,
 |   msgq = {
 |     lh_first = 0x0
 |   },
 |   noprint = 1,
 |   c_option = 0x0,
 |   seqq = {
 |     lh_first = 0xfceb4f4d40f0
 |   },
 |   seqb = "\000@\001\b", '\000' <repeats 11 times>,
 |   cname = {{
 |       name = "^@\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^A\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^B\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^C\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^D\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^E\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^F\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^G\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^H\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^I\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^J\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^K\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^L\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^M\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^N\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^O\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^P\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Q\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^R\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^S\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^T\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^U\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^V\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^W\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^X\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Y\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^Z\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^[\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^\\\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^]\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^^\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "^_\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = " \000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "!\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "\"\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "#\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "$\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "%\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "&\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "'\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "(\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ")\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "*\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "+\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ",\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "-\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ".\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "/\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "0\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "1\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "2\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "3\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "4\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "5\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "6\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "7\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "8\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "9\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ":\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ";\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "<\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "=\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = ">\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "?\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "@\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "A\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "B\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "C\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "D\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "E\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "F\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "G\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "H\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "I\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "J\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "K\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "L\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "M\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "N\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "O\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "P\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Q\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "R\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "S\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "T\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "U\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "V\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "W\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "X\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Y\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "Z\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "[\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "\\\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "]\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "^\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "_\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "`\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "a\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "b\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "c\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "d\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "e\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "f\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "g\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "h\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "i\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "j\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "k\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "l\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "m\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "n\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "o\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "p\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "q\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "r\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "s\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "t\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "u\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "v\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "w\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "x\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "y\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "z\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "{\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "|\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "}\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "~\000\000\000",
 |       len = 1 '\001'
 |     }, {
 |       name = "^?\000\000",
 |       len = 2 '\002'
 |     }, {
 |       name = "\\x80",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x81",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x82",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x83",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x84",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x85",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x86",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x87",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x88",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x89",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8a",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8b",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8c",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8d",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8e",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x8f",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x90",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x91",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x92",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x93",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x94",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x95",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x96",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x97",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x98",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x99",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9a",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9b",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9c",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9d",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9e",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\x9f",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa7",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa8",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xa9",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xaa",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xab",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xac",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xad",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xae",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xaf",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb7",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb8",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xb9",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xba",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbb",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbc",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbd",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbe",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xbf",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc0",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc1",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc2",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc3",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc4",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc5",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc6",
 |       len = 4 '\004'
 |     }, {
 |       name = "\\xc7",
 |       len = 4 '\004'
 |     }...},
 |   special_key = {K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_CNTRLD, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_VERASE, K_TAB, K_NL, K_NOTUSED, K_FORMFEED, K_CR, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_VLNEXT, K_CNTRLR, K_NOTUSED, K_CNTRLT, K_VKILL, K_VLNEXT, K_VWERASE, K_HEXCHAR, K_NOTUSED, K_CNTRLZ, K_ESCAPE, K_NOTUSED <repeats 13 times>, K_RIGHTPAREN, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_ZERO, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_NOTUSED, K_COLON, K_NOTUSED <repeats 33 times>, K_BACKSLASH, K_NOTUSED, K_CARAT, K_NOTUSED <repeats 30 times>, K_RIGHTBRACE, K_NOTUSED, K_VERASE, K_NOTUSED <repeats 128 times>},
 |   flags = 64,
 |   scr_addstr = 0x200105b10 <cl_addstr>,
 |   scr_waddstr = 0x200105ae4 <cl_waddstr>,
 |   scr_attr = 0x200105b3c <cl_attr>,
 |   scr_baud = 0x200105d64 <cl_baud>,
 |   scr_bell = 0x200105e38 <cl_bell>,
 |   scr_busy = 0x200159a1c <vs_busy>,
 |   scr_child = 0x0,
 |   scr_clrtoeol = 0x200105ef0 <cl_clrtoeol>,
 |   scr_cursor = 0x200105f40 <cl_cursor>,
 |   scr_deleteln = 0x200105fb0 <cl_deleteln>,
 |   scr_discard = 0x20010614c <cl_discard>,
 |   scr_event = 0x200107ae0 <cl_event>,
 |   scr_ex_adjust = 0x200106280 <cl_ex_adjust>,
 |   scr_fmap = 0x200109a1c <cl_fmap>,
 |   scr_keyval = 0x200106558 <cl_keyval>,
 |   scr_imctrl = 0x200106410 <cl_imctrl>,
 |   scr_insertln = 0x200106508 <cl_insertln>,
 |   scr_optchange = 0x200109c48 <cl_optchange>,
 |   scr_move = 0x2001066ac <cl_move>,
 |   scr_refresh = 0x200106750 <cl_refresh>,
 |   scr_rename = 0x200106a1c <cl_rename>,
 |   scr_reply = 0x0,
 |   scr_screen = 0x2001082b8 <cl_screen>,
 |   scr_split = 0x200106bf8 <cl_split>,
 |   scr_suspend = 0x200106cf0 <cl_suspend>,
 |   scr_usage = 0x200106f8c <cl_usage>,
 |   th_private = 0x0,
 |   run = 0x200137250 <vi_nothread_run>,
 |   lock_init = 0x200137278 <vi_nothread_lock>,
 |   lock_try = 0x200137278 <vi_nothread_lock>,
 |   lock_unlock = 0x200137278 <vi_nothread_lock>,
 |   lock_end = 0x200137278 <vi_nothread_lock>
 | }
 | (gdb) p gp
 | $2 = (GS *) 0x200195008
 | (gdb) disas/s
 | Dump of assembler code for function ex_writefp:
 | /tmp/src/external/bsd/nvi/dist/ex/ex_write.c:
 | 293     {
 |    0x000000020012d904 <+0>:     sub     sp, sp, #0x140
 |    0x000000020012d908 <+4>:     str     x30, [sp]
 |    0x000000020012d90c <+8>:     str     x0, [sp, #72]
 |    0x000000020012d910 <+12>:    str     x1, [sp, #64]
 |    0x000000020012d914 <+16>:    str     x2, [sp, #56]
 |    0x000000020012d918 <+20>:    str     x3, [sp, #48]
 |    0x000000020012d91c <+24>:    str     x4, [sp, #40]
 |    0x000000020012d920 <+28>:    str     x5, [sp, #32]
 |    0x000000020012d924 <+32>:    str     x6, [sp, #24]
 |    0x000000020012d928 <+36>:    str     w7, [sp, #20]
 | 
 | 294             struct stat sb;
 | 295             GS *gp;
 | 296             u_long ccnt;                    /* XXX: can't print off_t portably. */
 | 297             db_recno_t fline, tline, lcnt;
 | 298             size_t len;
 | 299             int rval;
 | 300             const char *msg;
 | 301             CHAR_T *p;
 | 302             const char *f;
 | 303             size_t flen;
 | 304
 | 305             gp = sp->gp;
 | => 0x000000020012d92c <+40>:    ldr     x0, [sp, #72]
 |    0x000000020012d930 <+44>:    ldr     x0, [x0, #48]
 |    0x000000020012d934 <+48>:    str     x0, [sp, #280]
 | 
 | 306             fline = fm->lno;
 |    0x000000020012d938 <+52>:    ldr     x0, [sp, #48]
 |    0x000000020012d93c <+56>:    ldr     w0, [x0]
 |    0x000000020012d940 <+60>:    str     w0, [sp, #308]
 | 
 | 307             tline = tm->lno;
 |    0x000000020012d944 <+64>:    ldr     x0, [sp, #40]
 |    0x000000020012d948 <+68>:    ldr     w0, [x0]
 |    0x000000020012d94c <+72>:    str     w0, [sp, #276]
 |
 | [... more assembler dump output truncated ...]
 | End of assembler dump.
 | (gdb) info reg
 | x0             0xfceb4f657000      278087579561984
 | x1             0x200175588         8591463816
 | x2             0xfceb4f85e730      278087581689648
 | x3             0xfceb4fb0c118      278087584497944
 | x4             0xfceb4fb0c128      278087584497960
 | x5             0x0                 0
 | x6             0x0                 0
 | x7             0x1                 1
 | x8             0x3808              14344
 | x9             0x6                 6
 | x10            0x40                64
 | x11            0x3f                63
 | x12            0x3f3ad3e17ca       4345118463946
 | x13            0x3f3ad3e17cd       4345118463949
 | x14            0xfceb4fa7d238      278087583912504
 | x15            0xfceb4f85f378      278087581692792
 | x16            0xfceb4f8517d8      278087581636568
 | x17            0xfceb4f6b9c98      278087579966616
 | x18            0x1c10              7184
 | x19            0x20010b378         8591029112
 | x20            0x200195008         8591593480
 | x21            0xffffffc5ffe0      281474972909536
 | x22            0x200196640         8591599168
 | x23            0x0                 0
 | x24            0xffffffc5ffe0      281474972909536
 | x25            0xfffffbd40000      281474906718208
 | x26            0x0                 0
 | x27            0x0                 0
 | x28            0x0                 0
 | x29            0x0                 0
 | x30            0x20011ae4c         8591093324
 | sp             0xffffffc5dff0      0xffffffc5dff0
 | pc             0x20012d92c         0x20012d92c <ex_writefp+40>
 | cpsr           0x20000000          [ EL=0 C ]
 | fpsr           0x0                 0
 | fpcr           0x0                 0
 | (gdb) p $sp
 | $3 = (void *) 0xffffffc5dff0
 | (gdb) p $sp + 0x72
 | $4 = (void *) 0xffffffc5e062
 | (gdb) x/16x $sp + 0x72
 | 0xffffffc5e062: 0x00000000      0xeaac0000      0xfceb4f7c      0xb3780000
 | 0xffffffc5e072: 0x00020010      0x50080000      0x00020019      0xffe00000
 | 0xffffffc5e082: 0xffffffc5      0xae0c0000      0x00020011      0xebc00000
 | 0xffffffc5e092: 0x06014fa6      0x90100000      0xfceb4fb1      0x39100000
 | (gdb) p $w7
 | $5 = 1
 | (gdb) p $sp + 0x20
 | $6 = (void *) 0xffffffc5e010
 | (gdb) x/16x $sp + 0x20
 | 0xffffffc5e010: 0x00000000      0x00000000      0x4fb0c128      0x0000fceb
 | 0xffffffc5e020: 0x4fb0c118      0x0000fceb      0x4f85e730      0x0000fceb
 | 0xffffffc5e030: 0x00175588      0x00000002      0x4f657000      0x0000fceb
 | 0xffffffc5e040: 0x00000004      0x00000000      0x4fa6ea68      0x0000fceb
 | (gdb) quit
 | A debugging session is active.
 | 
 |         Inferior 1 [process 16366] will be detached.
 |         Inferior 2 [process 14304] will be detached.
 |         Inferior 4 [process 15574] will be detached.
 | 
 | Quit anyway? (y or n) y
 | Detaching from program: /tmp/src/external/bsd/nvi/usr.bin/nvi/vi, process 16366
 | [Inferior 1 (process 16366) detached]
 | Detaching from program: /usr/pkg/bin/tcsh, process 14304
 | [Inferior 2 (process 14304) detached]
 | Detaching from program: /tmp/src/external/bsd/nvi/usr.bin/nvi/vi, process 15574
 | [Inferior 4 (process 15574) detached]