(gdb) break decx
Breakpoint 1 at 0x4125bf: file xheader.c, line 610.
(gdb) break path_decoder
Breakpoint 2 at 0x413a41: file xheader.c, line 1173.
(gdb) run

Breakpoint 1, decx (data=0x65aca0, keyword=0x660b43 "GNU.sparse.major", value=0x660b54 "1", size=1) at xheader.c:610
610       struct tar_stat_info *st = data;
(gdb) cont

Breakpoint 1, decx (data=0x65aca0, keyword=0x660b59 "GNU.sparse.minor", value=0x660b6a "0", size=1) at xheader.c:610
610       struct tar_stat_info *st = data;
(gdb)

Breakpoint 1, decx (data=0x65aca0, keyword=0x660b70 "GNU.sparse.name", value=0x660b80 "123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=111) at xheader.c:610
610       struct tar_stat_info *st = data;
(gdb)

Breakpoint 2, path_decoder (st=0x65aca0, keyword=0x660b70 "GNU.sparse.name", arg=0x660b80 "123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=111) at xheader.c:1173
1173      decode_string (&st->orig_file_name, arg);
(gdb) finish
0x0000000000412623 in decx (data=0x65aca0, keyword=0x660b70 "GNU.sparse.name", value=0x660b80 "123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=111) at xheader.c:618
618         t->decoder (st, keyword, value, size);
(gdb) print st->file_name
$1 = 0x66ad40 "123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960"
(gdb) cont

Breakpoint 1, decx (data=0x65aca0, keyword=0x660bf3 "GNU.sparse.realsize", value=0x660c07 "10485760", size=8) at xheader.c:610
610       struct tar_stat_info *st = data;
(gdb)

Breakpoint 1, decx (data=0x65aca0, keyword=0x660c14 "path", value=0x660c19 "./GNUSparseFile.18026/123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=133) at xheader.c:610
610       struct tar_stat_info *st = data;
(gdb)

Breakpoint 2, path_decoder (st=0x65aca0, keyword=0x660c14 "path", arg=0x660c19 "./GNUSparseFile.18026/123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=133) at xheader.c:1173
1173      decode_string (&st->orig_file_name, arg);
(gdb) finish
0x0000000000412623 in decx (data=0x65aca0, keyword=0x660c14 "path", value=0x660c19 "./GNUSparseFile.18026/123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960", size=133) at xheader.c:618
618         t->decoder (st, keyword, value, size);
(gdb) print st->file_name
$2 = 0x66a630 "./GNUSparseFile.18026/123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960"