$ echo -e '<meta charset=gb18030>\n<a target=\x80><meta charset=hz>\n\x1b' | ./w3m -T text/html -dump

Program received signal SIGSEGV, Segmentation fault.
0x0000000000481b3d in wc_push_to_iso2022 (os=0x7cc2c0, cc=..., st=0x7fffffffc7d0) at iso2022.c:408
408             g = cs94_gmap[WC_CCS_INDEX(cc.ccs) - WC_F_ISO_BASE];
(gdb) p cc.ccs
$1 = 256
(gdb) bt
#0  0x0000000000481b3d in wc_push_to_iso2022 (os=0x7cc2c0, cc=..., st=0x7fffffffc7d0) at iso2022.c:408
#1  0x000000000047edb2 in wc_conv_to_ces (is=0x7cc2e0, ces=2099217) at conv.c:93
#2  0x000000000047eacf in wc_Str_conv (is=0x7cc2e0, f_ces=3211264, t_ces=2099217) at conv.c:23
#3  0x000000000047eb32 in wc_Str_conv_strict (is=0x7cc2e0, f_ces=3211264, t_ces=2099217) at conv.c:37
#4  0x000000000042903c in HTMLlineproc2body (buf=0x7cee00, feed=0x427fa1 <textlist_feed>, llimit=-1) at file.c:5664
#5  0x000000000042aba1 in HTMLlineproc2 (buf=0x7cee00, tl=0x7cc5e0) at file.c:6173
#6  0x000000000042dd6e in loadHTMLstream (f=0x7fffffffd120, newBuf=0x7cee00, src=0x0, internal=0) at file.c:7258
#7  0x000000000042c597 in loadHTMLBuffer (f=0x7fffffffd120, newBuf=0x7cee00) at file.c:6755
#8  0x0000000000416a40 in loadSomething (f=0x7fffffffd120, loadproc=0x42c4b2 <loadHTMLBuffer>, defaultbuf=0x7cee00) at file.c:224
#9  0x000000000041c7e6 in loadGeneralFile (path=0x7c3ae0 "/tmp/zshWcHIdH", current=0x0, referer=0xffffffffffffffff <error: Cannot access memory at address 0xffffffffffffffff>,
    flag=0, request=0x0) at file.c:2241
#10 0x00000000004070d1 in main (argc=5, argv=0x7fffffffd448, envp=0x7fffffffd478) at main.c:1020