Use of uninitialised value by /\s/u

valgrind e$B$N7k2L$r$^$?D4$Y$k$H!"e(B/\s/u e$B$GL$=i4|2=%a%b%j$r;HMQe(B
e$B$9$k$h$&$G$9!#e(B

% valgrind ./ruby -ve ‘/\s/u’
==13719== Memcheck, a memory error detector.
==13719== Copyright © 2002-2006, and GNU GPL’d, by Julian Seward et
al.
==13719== Using LibVEX rev 1658, a library for dynamic binary
translation.
==13719== Copyright © 2004-2006, and GNU GPL’d, by OpenWorks LLP.
==13719== Using valgrind-3.2.1-Debian, a dynamic binary instrumentation
framework.
==13719== Copyright © 2000-2006, and GNU GPL’d, by Julian Seward et
al.
==13719== For more details, rerun with: -v
==13719==
–13719-- DWARF2 CFI reader: unhandled CFI instruction 0:50
–13719-- DWARF2 CFI reader: unhandled CFI instruction 0:50
–13719-- DWARF2 CFI reader: unhandled CFI instruction 0:50
–13719-- DWARF2 CFI reader: unhandled CFI instruction 0:50
ruby 1.9.0 (2007-06-27 patchlevel 0) [i686-linux]
==13719== Use of uninitialised value of size 4
==13719== at 0x80C3A6B: st_add_direct (st.c:301)
==13719== by 0x80BB407: parse_exp (regparse.c:5046)
==13719== by 0x80BB9E4: parse_branch (regparse.c:5223)
==13719== by 0x80BBB3B: parse_subexp (regparse.c:5260)
==13719== by 0x80BBCDC: parse_regexp (regparse.c:5304)
==13719== by 0x80BBD8E: onig_parse_make_tree (regparse.c:5331)
==13719== by 0x80A7B89: onig_compile (regcomp.c:5364)
==13719== by 0x809A50F: make_regexp (re.c:711)
==13719== by 0x809BF34: rb_reg_initialize (re.c:1489)
==13719== by 0x809C0CD: rb_reg_compile (re.c:1527)
==13719== by 0x8086D46: ruby_yyparse (parse.y:3601)
==13719== by 0x8088AD6: yycompile (parse.y:4626)
==13719==
==13719== Use of uninitialised value of size 4
==13719== at 0x80C3A84: st_add_direct (st.c:301)
==13719== by 0x80BB407: parse_exp (regparse.c:5046)
==13719== by 0x80BB9E4: parse_branch (regparse.c:5223)
==13719== by 0x80BBB3B: parse_subexp (regparse.c:5260)
==13719== by 0x80BBCDC: parse_regexp (regparse.c:5304)
==13719== by 0x80BBD8E: onig_parse_make_tree (regparse.c:5331)
==13719== by 0x80A7B89: onig_compile (regcomp.c:5364)
==13719== by 0x809A50F: make_regexp (re.c:711)
==13719== by 0x809BF34: rb_reg_initialize (re.c:1489)
==13719== by 0x809C0CD: rb_reg_compile (re.c:1527)
==13719== by 0x8086D46: ruby_yyparse (parse.y:3601)
==13719== by 0x8088AD6: yycompile (parse.y:4626)
warning: useless use of a literal in void context
==13719==
==13719== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 19 from
1)
==13719== malloc/free: in use at exit: 881,991 bytes in 7,040 blocks.
==13719== malloc/free: 7,136 allocs, 96 frees, 888,749 bytes allocated.
==13719== For counts of detected errors, rerun with: -v
==13719== searching for pointers to 7,040 not-freed blocks.
==13719== checked 649,916 bytes.
==13719==
==13719== LEAK SUMMARY:
==13719== definitely lost: 0 bytes in 0 blocks.
==13719== possibly lost: 68 bytes in 1 blocks.
==13719== still reachable: 881,923 bytes in 7,039 blocks.
==13719== suppressed: 0 bytes in 0 blocks.
==13719== Reachable blocks (those to which a pointer was found) are not
shown.
==13719== To see them, rerun with: --show-reachable=yes