Update Gnulib to the latest git version

This patch allows us to remove a workaround in common-defs.h due to
the gnulib fix in:
https://lists.gnu.org/archive/html/bug-gnulib/2019-11/msg00024.html

All of GDB's local Gnulib patches were already fixed upstream per their
descriptions, so this patch removes them all.

The problem listed here:
https://sourceware.org/ml/gdb-patches/2019-08/msg00553.html
was probably partially fixed by moving gnulib to the toplevel;
for the remainder, I am setting MAKEOVERRIDES to empty in
gnulib/Makefile.am.  See also the comment there (it fixes an issue
with compilers that don't use C99/C11 by default such as GCC 4.8.5,
the default on Centos 7).

gdb/ChangeLog:

2019-12-16  Christian Biesinger  <cbiesinger@google.com>

	* gdbsupport/common-defs.h: Remove workaround for a gnulib bug
	(we no longer need to include time.h before pathmax.h)

gnulib/ChangeLog:

2019-12-16  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.am: Set MAKEOVERRIDES.
	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* config.in: Regenerate.
	* configure: Regenerate.
	* import/Makefile.am: Update.
	* import/Makefile.in: Regenerate.
	* import/_Noreturn.h: New file.
	* import/alloca.c (i00afunc): Update.
	* import/alloca.in.h (if): Update.
	* import/arg-nonnull.h: Rename from import/extra/snippet/arg-nonnull.h.
	* import/arpa_inet.in.h (if): Update.
	* import/assure.h: Update.
	* import/at-func.c: Update.
	* import/basename-lgpl.c: Update.
	* import/canonicalize-lgpl.c (if): Update.
	* import/c++defs.h: Rename from import/extra/snippet/c++defs.h.
	* import/cdefs.h: New file.
	* import/chdir-long.c: Update.
	* import/chdir-long.h: Update.
	* import/cloexec.c: Update.
	* import/cloexec.h: Update.
	* import/close.c: Update.
	* import/closedir.c: Update.
	* import/config.charset: Remove.
	* import/dirent-private.h: Update.
	* import/dirent.in.h: Update.
	* import/dirfd.c: Update.
	* import/dirname-lgpl.c: Update.
	* import/dirname.h (base_name): Update.
	* import/dosname.h (if): Update.
	* import/dup-safer-flag.c: New file.
	* import/dup-safer.c: Update.
	* import/dup.c: Update.
	* import/dup2.c (if): Update.
	(dup2_nothrow): Update.
	(ms_windows_dup2): Update.
	* import/errno.in.h (if): Update.
	(elif): Update.
	* import/error.c (if): Update.
	(strerror_r): Update.
	(program_name): Update.
	(error): Update.
	(error_at_line): Update.
	* import/error.h: Update.
	* import/exitfail.c: Update.
	* import/exitfail.h: Update.
	* import/extra/config.rpath: Update.
	* import/extra/snippet/_Noreturn.h: Remove.
	* import/extra/update-copyright: Update.
	* import/fchdir.c: Update.
	* import/fcntl.c (rpl_fcntl): Update.
	(INCL_DOS): Update.
	(if): Update.
	(rpl_fcntl_DUPFD): Update.
	(rpl_fcntl_DUPFD_CLOEXEC): Update.
	(klibc_fcntl): Update.
	(fcntl): Update.
	(have_dupfd_cloexec): Update.
	* import/fcntl.in.h (if): Update.
	(creat): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(_GL_WARN_ON_USE): Update.
	(O_CLOEXEC): Update.
	(GNULIB_defined_O_CLOEXEC): Update.
	* import/fd-hook.c: Update.
	* import/fd-hook.h: Update.
	* import/fd-safer-flag.c: New file.
	* import/fd-safer.c: Update.
	* import/fdopendir.c: Update.
	* import/filename.h: Update.
	* import/filenamecat-lgpl.c (longest_relative_suffix): Update.
	(mfile_name_concat): Update.
	* import/filenamecat.h: Update.
	* import/flexmember.h: Update.
	* import/float+.h: Update.
	* import/float.c: Update.
	* import/float.in.h (LDBL_MIN): Update.
	* import/fnmatch.c (__builtin_expect): Update.
	(FALLTHROUGH): Update.
	* import/fnmatch.in.h (_FNMATCH_H): Update.
	(_): Update.
	(fnmatch): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_FUNCDECL_SYS): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(_GL_WARN_ON_USE): Update.
	* import/fnmatch_loop.c (FCT): Update.
	(EXT): Update.
	* import/fpucw.h (GET_FPUCW): Update.
	(SET_FPUCW): Update.
	* import/frexp.c: Update.
	* import/frexpl.c: Update.
	* import/fstat.c (stat): Update.
	(fstat): Update.
	(WINDOWS_NATIVE): Update.
	(fstat_nothrow): Update.
	(WIN32_LEAN_AND_MEAN): Update.
	* import/fstatat.c (normal_fstatat): Update.
	(rpl_fstatat): Update.
	* import/getcwd-lgpl.c (rpl_getcwd): Update.
	* import/getcwd.c (getcwd_nothrow): Update.
	(getcwd_system): Update.
	(__getcwd): Update.
	* import/getdtablesize.c (if): Update.
	(_setmaxstdio): Update.
	(_setmaxstdio_nothrow): Update.
	(getdtablesize): Update.
	* import/getlogin_r.c (if): Update.
	(getlogin_r): Update.
	* import/getprogname.c (getprogname): Update.
	* import/getprogname.h: Update.
	* import/gettext.h (if): Update.
	* import/gettimeofday.c (WINDOWS_NATIVE): Update.
	(localtime): Update.
	(GetProcAddress): Update.
	(gmtime): Update.
	(void): Update.
	(struct tm): Update.
	(rpl_localtime): Update.
	(initialize): Update.
	(rpl_gmtime): Update.
	(tzset): Update.
	(rpl_tzset): Update.
	* import/glob-libc.h (_Restrict_): Update.
	(__size_t): Update.
	(__need_size_t): Update.
	(glob): Update.
	(globfree): Update.
	(__REDIRECT_NTH): Update.
	(glob64): Update.
	(globfree64): Update.
	(glob_pattern_p): Update.
	* import/glob.c (POSIX): Update.
	(if): Update.
	(__set_errno): Update.
	(getpwnam_r): Update.
	(__lstat64): Update.
	(FLEXIBLE_ARRAY_MEMBER): Update.
	(__glob_pattern_p): Update.
	(GETPW_R_SIZE_MAX): Update.
	(GET_LOGIN_NAME_MAX): Update.
	(DT_UNKNOWN): Update.
	(DT_DIR): Update.
	(DT_LNK): Update.
	(D_TYPE_TO_RESULT): Update.
	(readdir_result_might_be_symlink): Update.
	(readdir_result_might_be_dir): Update.
	(readdir_result_type): Update.
	(D_INO_TO_RESULT): Update.
	(READDIR_RESULT_INITIALIZER): Update.
	(attribute_hidden): Update.
	(__attribute_noinline__): Update.
	(__builtin_expect): Update.
	(__glibc_unlikely): Update.
	(__has_builtin): Update.
	(__glob_pattern_type): Update.
	(is_dir): Update.
	(glob): Update.
	(globfree): Update.
	(libc_hidden_def): Update.
	(DIRSEP_CHAR): Update.
	(prefix_array): Update.
	(weak_alias): Update.
	(link_exists2_p): Update.
	(link_exists_p): Update.
	(glob_in_dir): Update.
	(GLOBNAMES_MEMBERS): Update.
	* import/glob.in.h (_GL_GLOB_H): Update.
	(_): Update.
	(__BEGIN_DECLS): Update.
	(__END_DECLS): Update.
	(_Restrict_): Update.
	(__THROW): Update.
	(__THROWNL): Update.
	(__size_t): Update.
	(__USE_GNU): Update.
	(glob): Update.
	(globfree): Update.
	(glob_pattern_p): Update.
	(__glob_pattern_p): Update.
	(__GLOB_GNULIB): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_FUNCDECL_SYS): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_WARN_ON_USE): Update.
	* import/glob_internal.h: New file.
	* import/glob_pattern_p.c: New file.
	* import/globfree.c: New file.
	* import/glthread/lock.c (glthread_rwlock_init_for_glibc): Update.
	(glthread_rwlock_rdlock_multithreaded): Update.
	(glthread_once_call): Update.
	(glthread_once_multithreaded): Update.
	(glthread_once_singlethreaded): Update.
	(glthread_recursive_lock_init_multithreaded): Update.
	(glthread_recursive_lock_lock_multithreaded): Update.
	(glthread_recursive_lock_unlock_multithreaded): Update.
	(glthread_recursive_lock_destroy_multithreaded): Update.
	(glthread_lock_init_func): Update.
	(glthread_lock_lock_func): Update.
	(glthread_lock_unlock_func): Update.
	(glthread_lock_destroy_func): Update.
	(gl_waitqueue_t): Update.
	(gl_waitqueue_init): Update.
	(gl_waitqueue_add): Update.
	(gl_waitqueue_notify_first): Update.
	(gl_waitqueue_notify_all): Update.
	(glthread_rwlock_init_func): Update.
	(glthread_rwlock_rdlock_func): Update.
	(glthread_rwlock_wrlock_func): Update.
	(glthread_rwlock_unlock_func): Update.
	(glthread_rwlock_destroy_func): Update.
	(glthread_recursive_lock_init_func): Update.
	(glthread_recursive_lock_lock_func): Update.
	(glthread_recursive_lock_unlock_func): Update.
	(glthread_recursive_lock_destroy_func): Update.
	(glthread_once_func): Update.
	* import/glthread/lock.h (c11_threads_in_use): Update.
	(pthread_in_use): Update.
	(gl_rwlock_initializer): Update.
	(glthread_rwlock_init): Update.
	(glthread_rwlock_init_for_glibc): Update.
	(pth_in_use): Update.
	(gl_lock_define): Update.
	(gl_lock_define_initialized): Update.
	(gl_lock_initializer): Update.
	(glthread_lock_init): Update.
	(glthread_lock_lock): Update.
	(glthread_lock_unlock): Update.
	(glthread_lock_destroy): Update.
	(gl_rwlock_define): Update.
	(gl_rwlock_define_initialized): Update.
	(glthread_rwlock_rdlock): Update.
	(glthread_rwlock_wrlock): Update.
	(glthread_rwlock_unlock): Update.
	(glthread_rwlock_destroy): Update.
	(gl_recursive_lock_define): Update.
	(gl_recursive_lock_define_initialized): Update.
	(gl_recursive_lock_initializer): Update.
	(glthread_recursive_lock_init): Update.
	(glthread_recursive_lock_lock): Update.
	(glthread_recursive_lock_unlock): Update.
	(glthread_recursive_lock_destroy): Update.
	(gl_once_define): Update.
	(glthread_once): Update.
	(glthread_once_multithreaded): Update.
	(glthread_once_singlethreaded): Update.
	(thread_in_use): Update.
	(glthread_recursive_lock_init_multithreaded): Update.
	(glthread_recursive_lock_lock_multithreaded): Update.
	(glthread_recursive_lock_unlock_multithreaded): Update.
	(glthread_recursive_lock_destroy_multithreaded): Update.
	(glthread_lock_init_func): Update.
	(glthread_lock_lock_func): Update.
	(glthread_lock_unlock_func): Update.
	(glthread_lock_destroy_func): Update.
	(glthread_rwlock_init_func): Update.
	(glthread_rwlock_rdlock_func): Update.
	(glthread_rwlock_wrlock_func): Update.
	(glthread_rwlock_unlock_func): Update.
	(glthread_rwlock_destroy_func): Update.
	(glthread_recursive_lock_init_func): Update.
	(glthread_recursive_lock_lock_func): Update.
	(glthread_recursive_lock_unlock_func): Update.
	(glthread_recursive_lock_destroy_func): Update.
	(glthread_once_func): Update.
	* import/glthread/threadlib.c: Update.
	* import/hard-locale.c: Update.
	* import/hard-locale.h: Update.
	* import/inet_ntop.c: Update.
	* import/intprops.h (__has_builtin): Update.
	(_GL_INT_CONVERT): Update.
	(_GL_INT_NEGATE_CONVERT): Update.
	(verify): Update.
	(_GL_HAS_BUILTIN_OVERFLOW): Update.
	(_GL_HAS_BUILTIN_ADD_OVERFLOW): Update.
	(_GL_HAS_BUILTIN_OVERFLOW_P): Update.
	(_GL_HAS_BUILTIN_MUL_OVERFLOW): Update.
	(_GL_BINARY_OP_OVERFLOW): Update.
	(INT_ADD_WRAPV): Update.
	(INT_SUBTRACT_WRAPV): Update.
	(INT_MULTIPLY_WRAPV): Update.
	(_GL_INT_OP_WRAPV): Update.
	(_GL_INT_OP_WRAPV_SMALLISH): Update.
	(_GL_INT_OP_WRAPV_LONGISH): Update.
	(_GL_INT_OP_CALC): Update.
	(_GL_INT_OP_CALC1): Update.
	(_GL_INT_OP_WRAPV_VIA_UNSIGNED): Update.
	(_GL_INT_ADD_RANGE_OVERFLOW): Update.
	(_GL_INT_SUBTRACT_RANGE_OVERFLOW): Update.
	(_GL_INT_MULTIPLY_RANGE_OVERFLOW): Update.
	* import/inttypes.in.h (if): Update.
	* import/isnan.c: Update.
	* import/isnand-nolibm.h: Update.
	* import/isnand.c: Update.
	* import/isnanl-nolibm.h: Update.
	* import/isnanl.c: Update.
	* import/itold.c: Update.
	* import/libc-config.h: New file.
	* import/limits.in.h (LLONG_MIN): Update.
	(LLONG_MAX): Update.
	(ULLONG_MAX): Update.
	(WORD_BIT): Update.
	(LONG_BIT): Update.
	* import/localcharset.c (setlocale): Update.
	(relocate): Update.
	(O_NOFOLLOW): Update.
	(ISSLASH): Update.
	(DIRECTORY_SEPARATOR): Update.
	(getc): Update.
	(volatile): Update.
	(get_charset_aliases): Update.
	(struct table_entry): Update.
	(alias_table_defined): Update.
	(locale_table_defined): Update.
	(locale_charset): Update.
	(if): Update.
	* import/localcharset.h: Update.
	* import/localtime-buffer.c: New file.
	* import/localtime-buffer.h: New file.
	* import/lstat.c (rpl_lstat): Update.
	* import/m4/00gnulib.m4: Update.
	* import/m4/__inline.m4: New file.
	* import/m4/absolute-header.m4: Update.
	* import/m4/alloca.m4: Update.
	* import/m4/arpa_inet_h.m4: Update.
	* import/m4/builtin-expect.m4: New file.
	* import/m4/canonicalize.m4: Update.
	* import/m4/chdir-long.m4: Update.
	* import/m4/close.m4: Update.
	* import/m4/closedir.m4: Update.
	* import/m4/codeset.m4: Update.
	* import/m4/configmake.m4: Remove.
	* import/m4/d-ino.m4: Update.
	* import/m4/d-type.m4: Update.
	* import/m4/dirent_h.m4: Update.
	* import/m4/dirfd.m4: Update.
	* import/m4/dirname.m4: Update.
	* import/m4/double-slash-root.m4: Update.
	* import/m4/dup.m4: Update.
	* import/m4/dup2.m4: Update.
	* import/m4/eealloc.m4: Update.
	* import/m4/environ.m4: Update.
	* import/m4/errno_h.m4: Update.
	* import/m4/error.m4: Update.
	* import/m4/exponentd.m4: Update.
	* import/m4/exponentl.m4: Update.
	* import/m4/extensions.m4: Update.
	* import/m4/extern-inline.m4: Update.
	* import/m4/fchdir.m4: Update.
	* import/m4/fcntl-o.m4: Update.
	* import/m4/fcntl.m4: Update.
	* import/m4/fcntl_h.m4: Update.
	* import/m4/fdopendir.m4: Update.
	* import/m4/filenamecat.m4: Update.
	* import/m4/flexmember.m4: Update.
	* import/m4/float_h.m4: Update.
	* import/m4/fnmatch.m4: Update.
	* import/m4/fnmatch_h.m4: New file.
	* import/m4/fpieee.m4: Update.
	* import/m4/frexp.m4: Update.
	* import/m4/frexpl.m4: Update.
	* import/m4/fstat.m4: Update.
	* import/m4/fstatat.m4: Update.
	* import/m4/getcwd-abort-bug.m4: Update.
	* import/m4/getcwd-path-max.m4: Update.
	* import/m4/getcwd.m4: Update.
	* import/m4/getdtablesize.m4: Update.
	* import/m4/getlogin.m4: New file.
	* import/m4/getlogin_r.m4: Update.
	* import/m4/getpagesize.m4: New file.
	* import/m4/getprogname.m4: Update.
	* import/m4/gettimeofday.m4: Update.
	* import/m4/glibc21.m4: Remove.
	* import/m4/glob.m4: Update.
	* import/m4/glob_h.m4: New file.
	* import/m4/gnulib-cache.m4: Update.
	* import/m4/gnulib-common.m4: Update.
	* import/m4/gnulib-comp.m4: Update.
	* import/m4/gnulib-tool.m4: Update.
	* import/m4/hard-locale.m4: Remove.
	* import/m4/host-cpu-c-abi.m4: New file.
	* import/m4/include_next.m4: Update.
	* import/m4/inet_ntop.m4: Update.
	* import/m4/inttypes-pri.m4: Update.
	* import/m4/inttypes.m4: Update.
	* import/m4/isnand.m4: Update.
	* import/m4/isnanl.m4: Update.
	* import/m4/largefile.m4: Update.
	* import/m4/lib-ld.m4: Update.
	* import/m4/lib-link.m4: Update.
	* import/m4/lib-prefix.m4: Update.
	* import/m4/limits-h.m4: Update.
	* import/m4/localcharset.m4: Update.
	* import/m4/locale-fr.m4: Update.
	* import/m4/locale-ja.m4: Update.
	* import/m4/locale-zh.m4: Update.
	* import/m4/localtime-buffer.m4: New file.
	* import/m4/lock.m4: Update.
	* import/m4/longlong.m4: Update.
	* import/m4/lstat.m4: Update.
	* import/m4/malloc.m4: Update.
	* import/m4/malloca.m4: Update.
	* import/m4/math_h.m4: Update.
	* import/m4/mbrtowc.m4: Update.
	* import/m4/mbsinit.m4: Update.
	* import/m4/mbsrtowcs.m4: Update.
	* import/m4/mbstate_t.m4: Update.
	* import/m4/memchr.m4: Update.
	* import/m4/memmem.m4: Update.
	* import/m4/mempcpy.m4: Update.
	* import/m4/memrchr.m4: Update.
	* import/m4/mkdir.m4: Update.
	* import/m4/mkdtemp.m4: Update.
	* import/m4/mkostemp.m4: Update.
	* import/m4/mmap-anon.m4: Update.
	* import/m4/mode_t.m4: Update.
	* import/m4/msvc-inval.m4: Update.
	* import/m4/msvc-nothrow.m4: Update.
	* import/m4/multiarch.m4: Update.
	* import/m4/netinet_in_h.m4: Update.
	* import/m4/nocrash.m4: Update.
	* import/m4/off_t.m4: Update.
	* import/m4/onceonly.m4: Remove.
	* import/m4/open-cloexec.m4: New file.
	* import/m4/open-slash.m4: New file.
	* import/m4/open.m4: Update.
	* import/m4/openat.m4: Update.
	* import/m4/opendir.m4: Update.
	* import/m4/pathmax.m4: Update.
	* import/m4/pthread_rwlock_rdlock.m4: New file.
	* import/m4/rawmemchr.m4: Update.
	* import/m4/readdir.m4: Update.
	* import/m4/readlink.m4: Update.
	* import/m4/realloc.m4: Update.
	* import/m4/rename.m4: Update.
	* import/m4/rewinddir.m4: Update.
	* import/m4/rmdir.m4: Update.
	* import/m4/save-cwd.m4: Update.
	* import/m4/secure_getenv.m4: Remove.
	* import/m4/setenv.m4: Update.
	* import/m4/signal_h.m4: Update.
	* import/m4/socklen.m4: Update.
	* import/m4/sockpfaf.m4: Update.
	* import/m4/ssize_t.m4: Update.
	* import/m4/stat-time.m4: New file.
	* import/m4/stat.m4: Update.
	* import/m4/std-gnu11.m4: New file.
	* import/m4/stdalign.m4: Update.
	* import/m4/stdbool.m4: Update.
	* import/m4/stddef_h.m4: Update.
	* import/m4/stdint.m4: Update.
	* import/m4/stdio_h.m4: Update.
	* import/m4/stdlib_h.m4: Update.
	* import/m4/strchrnul.m4: Update.
	* import/m4/strdup.m4: Update.
	* import/m4/strerror.m4: Update.
	* import/m4/strerror_r.m4: Update.
	* import/m4/string_h.m4: Update.
	* import/m4/strstr.m4: Update.
	* import/m4/strtok_r.m4: Update.
	* import/m4/sys_socket_h.m4: Update.
	* import/m4/sys_stat_h.m4: Update.
	* import/m4/sys_time_h.m4: Update.
	* import/m4/sys_types_h.m4: Update.
	* import/m4/sys_uio_h.m4: Update.
	* import/m4/tempname.m4: Update.
	* import/m4/threadlib.m4: Update.
	* import/m4/time_h.m4: Update.
	* import/m4/time_r.m4: Update.
	* import/m4/unistd-safer.m4: Update.
	* import/m4/unistd_h.m4: Update.
	* import/m4/warn-on-use.m4: Update.
	* import/m4/wchar_h.m4: Update.
	* import/m4/wchar_t.m4: Update.
	* import/m4/wctype_h.m4: Update.
	* import/m4/wint_t.m4: Update.
	* import/malloc.c: Update.
	* import/malloc/scratch_buffer.h: New file.
	* import/malloc/scratch_buffer_grow.c: New file.
	* import/malloc/scratch_buffer_grow_preserve.c: New file.
	* import/malloc/scratch_buffer_set_array_size.c: New file.
	* import/malloca.c (MAGIC_NUMBER): Update.
	(MAGIC_SIZE): Update.
	(struct preliminary_header): Update.
	(HEADER_SIZE): Update.
	(union header): Update.
	(verify): Update.
	(HASH_TABLE_SIZE): Update.
	(freea): Update.
	* import/malloca.h (malloca): Update.
	(nmalloca): Update.
	* import/malloca.valgrind: Remove.
	* import/math.in.h (_GL_MATH_CXX_REAL_FLOATING_DECL_2): Update.
	(func): Update.
	(rpl_func): Update.
	(f): Update.
	(d): Update.
	(l): Update.
	(_GL_WARN_ON_USE): Update.
	(_GL_WARN_ON_USE_ATTRIBUTE): Update.
	(FP_ILOGB0): Update.
	(FP_ILOGBNAN): Update.
	(acosf): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(asinf): Update.
	(atanf): Update.
	(atan2f): Update.
	(cosf): Update.
	(coshf): Update.
	(expf): Update.
	(expl): Update.
	(expm1l): Update.
	(ilogbl): Update.
	(rintl): Update.
	(sinf): Update.
	(sinhf): Update.
	(sqrtf): Update.
	(tanf): Update.
	(tanhf): Update.
	(isfinite): Update.
	(isinf): Update.
	(isnan): Update.
	(GNULIB_defined_signbit): Update.
	(signbit): Update.
	* import/mbrtowc.c (FALLTHROUGH): Update.
	(locale_enc): Update.
	(locale_enc_cached): Update.
	(gl_lock_define_initialized): Update.
	(mbrtowc): Update.
	* import/mbsinit.c (if): Update.
	(mbsinit): Update.
	* import/mbsrtowcs-impl.h: Update.
	* import/mbsrtowcs-state.c: Update.
	* import/mbsrtowcs.c: Update.
	* import/memchr.c: Update.
	* import/memchr.valgrind: Update.
	* import/memmem.c (__builtin_expect): Update.
	* import/mempcpy.c: Update.
	* import/memrchr.c (__memrchr): Update.
	* import/mkdir.c (if): Update.
	* import/mkdtemp.c: Update.
	* import/mkostemp.c: Update.
	* import/msvc-inval.c: Update.
	* import/msvc-inval.h: Update.
	* import/msvc-nothrow.c: Update.
	* import/msvc-nothrow.h (if): Update.
	* import/netinet_in.in.h: Update.
	* import/open.c (open): Update.
	(if): Update.
	* import/openat-die.c: Update.
	* import/openat-priv.h: Update.
	* import/openat-proc.c: Update.
	* import/openat.c (rpl_openat): Update.
	* import/openat.h: Update.
	* import/opendir.c: Update.
	* import/pathmax.h (if): Update.
	* import/pipe-safer.c: Update.
	* import/rawmemchr.c: Update.
	* import/rawmemchr.valgrind: Update.
	* import/readdir.c (readdir): Update.
	* import/readlink.c: Update.
	* import/realloc.c: Update.
	* import/ref-add.sin: Remove.
	* import/ref-del.sin: Remove.
	* import/rename.c (if): Update.
	* import/rewinddir.c: Update.
	* import/rmdir.c: Update.
	* import/same-inode.h (SAME_INODE): Update.
	* import/save-cwd.c (save_cwd): Update.
	* import/save-cwd.h: Update.
	* import/scratch_buffer.h: New file.
	* import/secure_getenv.c: Remove.
	* import/setenv.c: Update.
	* import/signal.in.h: Update.
	* import/stat-time.c: New file.
	* import/stat-time.h: New file.
	* import/stat-w32.c: New file.
	* import/stat-w32.h: New file.
	* import/stat.c (if): Update.
	(stat): Update.
	(REPLACE_FUNC_STAT_DIR): Update.
	(WINDOWS_NATIVE): Update.
	(WIN32_LEAN_AND_MEAN): Update.
	(is_unc_root): Update.
	(rpl_stat): Update.
	* import/stdalign.in.h (elif): Update.
	* import/stdbool.in.h: Update.
	* import/stddef.in.h (_GL_STDDEF_ALIGNAS): Update.
	(max_align_t): Update.
	(GNULIB_defined_max_align_t): Update.
	* import/stdint.in.h (WINT_MIN): Update.
	(WINT_MAX): Update.
	(_STDINT_MIN): Update.
	(_STDINT_UNSIGNED_MIN): Update.
	(_STDINT_SIGNED_MIN): Update.
	(PTRDIFF_MIN): Update.
	(SIG_ATOMIC_MIN): Update.
	(WCHAR_MIN): Update.
	* import/stdio.in.h (if): Update.
	* import/stdlib.in.h (if): Update.
	(_GL_WARN_ON_USE): Update.
	(_GL_FUNCDECL_SYS): Update.
	(random): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(srandom): Update.
	(initstate): Update.
	(setstate): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(GNULIB_defined_strtod_function): Update.
	(strtold): Update.
	(GNULIB_defined_strtold_function): Update.
	* import/str-two-way.h: Update.
	* import/strchrnul.c: Update.
	* import/strchrnul.valgrind: Update.
	* import/strdup.c: Update.
	* import/streq.h: Update.
	* import/strerror-override.c: Update.
	* import/strerror-override.h: Update.
	* import/strerror.c (strerror): Update.
	* import/strerror_r.c (safe_copy): Update.
	* import/string.in.h (_GL_FUNCDECL_SYS): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(_GL_WARN_ON_USE): Update.
	* import/stripslash.c: Update.
	* import/strnlen1.c: Update.
	* import/strnlen1.h: Update.
	* import/strstr.c (__builtin_expect): Update.
	* import/strtok_r.c: Update.
	* import/sys_socket.in.h (CMSG_SPACE): Update.
	(CMSG_LEN): Update.
	(struct sockaddr_storage): Update.
	(SO_REUSEPORT): Update.
	(_GL_WARN_ON_USE): Update.
	* import/sys_stat.in.h (if): Update.
	(stat): Update.
	(struct stat): Update.
	(st_atime): Update.
	(st_mtime): Update.
	(st_ctime): Update.
	(_GL_WINDOWS_STAT_TIMESPEC): Update.
	(GNULIB_defined_struct_stat): Update.
	(_S_IFBLK): Update.
	(_S_IFLNK): Update.
	(_S_IFSOCK): Update.
	(fstat): Update.
	(fstatat): Update.
	(lstat): Update.
	(stat64): Update.
	(_stat64): Update.
	(_stat32i64): Update.
	(_stati64): Update.
	(_stat32): Update.
	(_stat64i32): Update.
	* import/sys_time.in.h: Update.
	* import/sys_types.in.h (dev_t): Update.
	(GNULIB_defined_dev_t): Update.
	(ino_t): Update.
	(GNULIB_defined_ino_t): Update.
	(_GL_WINDOWS_STAT_INODES): Update.
	(if): Update.
	* import/sys_uio.in.h: Update.
	* import/tempname.c (__secure_getenv): Update.
	(try_nocreate): Update.
	* import/tempname.h: Update.
	* import/time.in.h (tzset): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_FUNCDECL_SYS): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(ctime): Update.
	(strftime): Update.
	* import/time_r.c: Update.
	* import/unistd--.h: Update.
	* import/unistd-safer.h: Update.
	* import/unistd.in.h (if): Update.
	(elif): Update.
	(__need_getopt): Update.
	(access): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(_GL_WARN_ON_USE): Update.
	(_GL_FUNCDECL_SYS): Update.
	(__declspec): Update.
	(_GL_WARN_ON_USE_ATTRIBUTE): Update.
	(faccessat): Update.
	(getpass): Update.
	(truncate): Update.
	* import/unsetenv.c: Update.
	* import/verify.h (if): Update.
	(_GL_HAVE__STATIC_ASSERT): Update.
	(_GL_HAVE_STATIC_ASSERT): Update.
	(_GL_HAVE__STATIC_ASSERT1): Update.
	(_GL_HAVE_STATIC_ASSERT1): Update.
	(_GL_VERIFY): Update.
	(_Static_assert): Update.
	(_GL_HAS_BUILTIN_TRAP): Update.
	(_GL_HAS_BUILTIN_UNREACHABLE): Update.
	(verify_true): Update.
	(verify): Update.
	(__has_builtin): Update.
	(elif): Update.
	(assume): Update.
	* import/warn-on-use.h: Rename from import/extra/snippet/warn-on-use.h.
	* import/wchar.in.h (if): Update.
	(wcsftime): Update.
	(_GL_FUNCDECL_RPL): Update.
	(_GL_CXXALIAS_RPL): Update.
	(_GL_FUNCDECL_SYS): Update.
	(_GL_CXXALIAS_SYS): Update.
	(_GL_CXXALIASWARN): Update.
	(_GL_WARN_ON_USE): Update.
	* import/wctype.in.h (rpl_iswalnum): Update.
	(rpl_iswalpha): Update.
	(rpl_iswblank): Update.
	(rpl_iswcntrl): Update.
	(rpl_iswdigit): Update.
	(rpl_iswgraph): Update.
	(rpl_iswlower): Update.
	(rpl_iswprint): Update.
	(rpl_iswpunct): Update.
	(rpl_iswspace): Update.
	(rpl_iswupper): Update.
	(rpl_iswxdigit): Update.
	(rpl_towlower): Update.
	(rpl_towupper): Update.
	(iswalnum): Update.
	(iswalpha): Update.
	(iswblank): Update.
	(iswcntrl): Update.
	(iswdigit): Update.
	(iswgraph): Update.
	(iswlower): Update.
	(iswprint): Update.
	(iswpunct): Update.
	(iswspace): Update.
	(iswupper): Update.
	(iswxdigit): Update.
	(towlower): Update.
	(towupper): Update.
	* import/windows-initguard.h: New file.
	* import/windows-mutex.c: New file.
	* import/windows-mutex.h: New file.
	* import/windows-once.c: New file.
	* import/windows-once.h: New file.
	* import/windows-recmutex.c: New file.
	* import/windows-recmutex.h: New file.
	* import/windows-rwlock.c: New file.
	* import/windows-rwlock.h: New file.
	* import/xalloc-oversized.h: New file.
	* patches/0001-Fix-PR-gdb-23558-Use-system-s-getcwd-when-cross-comp.patch: Remove.
	* patches/0002-mkostemp-mkostemps-Fix-compilation-error-in-C-mode-o.patch: Remove.
	* patches/0003-Fix-glob-c-Coverity-issues.patch: Remove.
	* update-gnulib.sh: Update to latest gnulib and don't apply patches
	anymore.  Also updates the patch -p flag to the current directory structure in
	case patches are needed again in the future.

Change-Id: I9c2b07a3046baecfb664e21b2644353ea888dbfa

1 files changed, 314 insertions, 187 deletions

diff --git a/gnulib/import/mbrtowc.c b/gnulib/import/mbrtowc.c
index cdd874b..1aad22c 100644
--- a/gnulib/import/mbrtowc.c
+++ b/gnulib/import/mbrtowc.c
@@ -1,5 +1,5 @@
 /* Convert multibyte character to wide character.
-   Copyright (C) 1999-2002, 2005-2016 Free Software Foundation, Inc.
+   Copyright (C) 1999-2002, 2005-2019 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2008.
 
    This program is free software: you can redistribute it and/or modify
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
@@ -34,7 +34,67 @@
 # include "localcharset.h"
 # include "streq.h"
 # include "verify.h"
+# include "glthread/lock.h"
+
+# ifndef FALLTHROUGH
+#  if __GNUC__ < 7
+#   define FALLTHROUGH ((void) 0)
+#  else
+#   define FALLTHROUGH __attribute__ ((__fallthrough__))
+#  endif
+# endif
+
+/* Returns a classification of special values of the encoding of the current
+   locale.  */
+typedef enum {
+  enc_other,      /* other */
+  enc_utf8,       /* UTF-8 */
+  enc_eucjp,      /* EUC-JP */
+  enc_94,         /* EUC-KR, GB2312, BIG5 */
+  enc_euctw,      /* EUC-TW */
+  enc_gb18030,    /* GB18030 */
+  enc_sjis        /* SJIS */
+} enc_t;
+static inline enc_t
+locale_enc (void)
+{
+  const char *encoding = locale_charset ();
+  if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
+    return enc_utf8;
+  if (STREQ_OPT (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
+    return enc_eucjp;
+  if (STREQ_OPT (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
+      || STREQ_OPT (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0)
+      || STREQ_OPT (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
+    return enc_94;
+  if (STREQ_OPT (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
+    return enc_euctw;
+  if (STREQ_OPT (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0))
+    return enc_gb18030;
+  if (STREQ_OPT (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
+    return enc_sjis;
+  return enc_other;
+}
+
+# if GNULIB_WCHAR_SINGLE
+/* When we know that the locale does not change, provide a speedup by
+   caching the value of locale_enc.  */
+static int cached_locale_enc = -1;
+static inline enc_t
+locale_enc_cached (void)
+{
+  if (cached_locale_enc < 0)
+    cached_locale_enc = locale_enc ();
+  return cached_locale_enc;
+}
+# else
+/* By default, don't make assumptions, hence no caching.  */
+#  define locale_enc_cached locale_enc
+# endif
 
+/* This lock protects the internal state of mbtowc against multiple simultaneous
+   calls of mbrtowc.  */
+gl_lock_define_initialized(static, mbtowc_lock)
 
 verify (sizeof (mbstate_t) >= 4);
 
@@ -65,6 +125,8 @@ mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
     char buf[4];
     const char *p;
     size_t m;
+    enc_t enc;
+    int res;
 
     switch (nstate)
       {
@@ -74,10 +136,10 @@ mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
         break;
       case 3:
         buf[2] = pstate[3];
-        /*FALLTHROUGH*/
+        FALLTHROUGH;
       case 2:
         buf[1] = pstate[2];
-        /*FALLTHROUGH*/
+        FALLTHROUGH;
       case 1:
         buf[0] = pstate[1];
         p = buf;
@@ -97,231 +159,296 @@ mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
 
     /* Here m > 0.  */
 
-# if __GLIBC__ || defined __UCLIBC__
-    /* Work around bug <http://sourceware.org/bugzilla/show_bug.cgi?id=9674> */
-    mbtowc (NULL, NULL, 0);
-# endif
-    {
-      int res = mbtowc (pwc, p, m);
-
-      if (res >= 0)
-        {
-          if (pwc != NULL && ((*pwc == 0) != (res == 0)))
-            abort ();
-          if (nstate >= (res > 0 ? res : 1))
-            abort ();
-          res -= nstate;
-          pstate[0] = 0;
-          return res;
-        }
+    enc = locale_enc_cached ();
 
-      /* mbtowc does not distinguish between invalid and incomplete multibyte
-         sequences.  But mbrtowc needs to make this distinction.
-         There are two possible approaches:
-           - Use iconv() and its return value.
-           - Use built-in knowledge about the possible encodings.
-         Given the low quality of implementation of iconv() on the systems that
-         lack mbrtowc(), we use the second approach.
-         The possible encodings are:
-           - 8-bit encodings,
-           - EUC-JP, EUC-KR, GB2312, EUC-TW, BIG5, GB18030, SJIS,
-           - UTF-8.
-         Use specialized code for each.  */
-      if (m >= 4 || m >= MB_CUR_MAX)
-        goto invalid;
-      /* Here MB_CUR_MAX > 1 and 0 < m < 4.  */
+    if (enc == enc_utf8) /* UTF-8 */
       {
-        const char *encoding = locale_charset ();
+        /* Achieve multi-thread safety by not calling mbtowc() at all.  */
+        /* Cf. unistr/u8-mbtouc.c.  */
+        unsigned char c = (unsigned char) p[0];
 
-        if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
+        if (c < 0x80)
           {
-            /* Cf. unistr/u8-mblen.c.  */
-            unsigned char c = (unsigned char) p[0];
-
-            if (c >= 0xc2)
-              {
-                if (c < 0xe0)
-                  {
-                    if (m == 1)
-                      goto incomplete;
-                  }
-                else if (c < 0xf0)
-                  {
-                    if (m == 1)
-                      goto incomplete;
-                    if (m == 2)
-                      {
-                        unsigned char c2 = (unsigned char) p[1];
-
-                        if ((c2 ^ 0x80) < 0x40
-                            && (c >= 0xe1 || c2 >= 0xa0)
-                            && (c != 0xed || c2 < 0xa0))
-                          goto incomplete;
-                      }
-                  }
-                else if (c <= 0xf4)
-                  {
-                    if (m == 1)
-                      goto incomplete;
-                    else /* m == 2 || m == 3 */
-                      {
-                        unsigned char c2 = (unsigned char) p[1];
-
-                        if ((c2 ^ 0x80) < 0x40
-                            && (c >= 0xf1 || c2 >= 0x90)
-                            && (c < 0xf4 || (c == 0xf4 && c2 < 0x90)))
-                          {
-                            if (m == 2)
-                              goto incomplete;
-                            else /* m == 3 */
-                              {
-                                unsigned char c3 = (unsigned char) p[2];
-
-                                if ((c3 ^ 0x80) < 0x40)
-                                  goto incomplete;
-                              }
-                          }
-                      }
-                  }
-              }
-            goto invalid;
+            if (pwc != NULL)
+              *pwc = c;
+            res = (c == 0 ? 0 : 1);
+            goto success;
           }
-
-        /* As a reference for this code, you can use the GNU libiconv
-           implementation.  Look for uses of the RET_TOOFEW macro.  */
-
-        if (STREQ_OPT (encoding,
-                       "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
+        if (c >= 0xc2)
           {
-            if (m == 1)
+            if (c < 0xe0)
               {
-                unsigned char c = (unsigned char) p[0];
-
-                if ((c >= 0xa1 && c < 0xff) || c == 0x8e || c == 0x8f)
+                if (m == 1)
                   goto incomplete;
-              }
-            if (m == 2)
-              {
-                unsigned char c = (unsigned char) p[0];
-
-                if (c == 0x8f)
+                else /* m >= 2 */
                   {
                     unsigned char c2 = (unsigned char) p[1];
 
-                    if (c2 >= 0xa1 && c2 < 0xff)
-                      goto incomplete;
+                    if ((c2 ^ 0x80) < 0x40)
+                      {
+                        if (pwc != NULL)
+                          *pwc = ((unsigned int) (c & 0x1f) << 6)
+                                 | (unsigned int) (c2 ^ 0x80);
+                        res = 2;
+                        goto success;
+                      }
                   }
               }
-            goto invalid;
-          }
-        if (STREQ_OPT (encoding,
-                       "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
-            || STREQ_OPT (encoding,
-                          "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0)
-            || STREQ_OPT (encoding,
-                          "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
-          {
-            if (m == 1)
+            else if (c < 0xf0)
               {
-                unsigned char c = (unsigned char) p[0];
-
-                if (c >= 0xa1 && c < 0xff)
+                if (m == 1)
                   goto incomplete;
-              }
-            goto invalid;
-          }
-        if (STREQ_OPT (encoding,
-                       "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
-          {
-            if (m == 1)
-              {
-                unsigned char c = (unsigned char) p[0];
+                else
+                  {
+                    unsigned char c2 = (unsigned char) p[1];
 
-                if ((c >= 0xa1 && c < 0xff) || c == 0x8e)
-                  goto incomplete;
-              }
-            else /* m == 2 || m == 3 */
-              {
-                unsigned char c = (unsigned char) p[0];
+                    if ((c2 ^ 0x80) < 0x40
+                        && (c >= 0xe1 || c2 >= 0xa0)
+                        && (c != 0xed || c2 < 0xa0))
+                      {
+                        if (m == 2)
+                          goto incomplete;
+                        else /* m >= 3 */
+                          {
+                            unsigned char c3 = (unsigned char) p[2];
 
-                if (c == 0x8e)
-                  goto incomplete;
+                            if ((c3 ^ 0x80) < 0x40)
+                              {
+                                if (pwc != NULL)
+                                  *pwc = ((unsigned int) (c & 0x0f) << 12)
+                                         | ((unsigned int) (c2 ^ 0x80) << 6)
+                                         | (unsigned int) (c3 ^ 0x80);
+                                res = 3;
+                                goto success;
+                              }
+                          }
+                      }
+                  }
               }
-            goto invalid;
-          }
-        if (STREQ_OPT (encoding,
-                       "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0))
-          {
-            if (m == 1)
+            else if (c <= 0xf4)
               {
-                unsigned char c = (unsigned char) p[0];
-
-                if ((c >= 0x90 && c <= 0xe3) || (c >= 0xf8 && c <= 0xfe))
+                if (m == 1)
                   goto incomplete;
-              }
-            else /* m == 2 || m == 3 */
-              {
-                unsigned char c = (unsigned char) p[0];
-
-                if (c >= 0x90 && c <= 0xe3)
+                else
                   {
                     unsigned char c2 = (unsigned char) p[1];
 
-                    if (c2 >= 0x30 && c2 <= 0x39)
+                    if ((c2 ^ 0x80) < 0x40
+                        && (c >= 0xf1 || c2 >= 0x90)
+                        && (c < 0xf4 || (c == 0xf4 && c2 < 0x90)))
                       {
                         if (m == 2)
                           goto incomplete;
-                        else /* m == 3 */
+                        else
                           {
                             unsigned char c3 = (unsigned char) p[2];
 
-                            if (c3 >= 0x81 && c3 <= 0xfe)
-                              goto incomplete;
+                            if ((c3 ^ 0x80) < 0x40)
+                              {
+                                if (m == 3)
+                                  goto incomplete;
+                                else /* m >= 4 */
+                                  {
+                                    unsigned char c4 = (unsigned char) p[3];
+
+                                    if ((c4 ^ 0x80) < 0x40)
+                                      {
+                                        if (pwc != NULL)
+                                          *pwc = ((unsigned int) (c & 0x07) << 18)
+                                                 | ((unsigned int) (c2 ^ 0x80) << 12)
+                                                 | ((unsigned int) (c3 ^ 0x80) << 6)
+                                                 | (unsigned int) (c4 ^ 0x80);
+                                        res = 4;
+                                        goto success;
+                                      }
+                                  }
+                              }
                           }
                       }
                   }
               }
-            goto invalid;
           }
-        if (STREQ_OPT (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
-          {
-            if (m == 1)
-              {
-                unsigned char c = (unsigned char) p[0];
+        goto invalid;
+      }
+    else
+      {
+        /* The hidden internal state of mbtowc would make this function not
+           multi-thread safe.  Achieve multi-thread safety through a lock.  */
+        gl_lock_lock (mbtowc_lock);
 
-                if ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xea)
-                    || (c >= 0xf0 && c <= 0xf9))
-                  goto incomplete;
-              }
-            goto invalid;
-          }
+        /* Put the hidden internal state of mbtowc into its initial state.
+           This is needed at least with glibc, uClibc, and MSVC CRT.
+           See <https://sourceware.org/bugzilla/show_bug.cgi?id=9674>.  */
+        mbtowc (NULL, NULL, 0);
 
-        /* An unknown multibyte encoding.  */
-        goto incomplete;
-      }
+        res = mbtowc (pwc, p, m);
 
-     incomplete:
-      {
-        size_t k = nstate;
-        /* Here 0 <= k < m < 4.  */
-        pstate[++k] = s[0];
-        if (k < m)
+        gl_lock_unlock (mbtowc_lock);
+
+        if (res >= 0)
+          {
+            if (pwc != NULL && ((*pwc == 0) != (res == 0)))
+              abort ();
+            goto success;
+          }
+
+        /* mbtowc does not distinguish between invalid and incomplete multibyte
+           sequences.  But mbrtowc needs to make this distinction.
+           There are two possible approaches:
+             - Use iconv() and its return value.
+             - Use built-in knowledge about the possible encodings.
+           Given the low quality of implementation of iconv() on the systems
+           that lack mbrtowc(), we use the second approach.
+           The possible encodings are:
+             - 8-bit encodings,
+             - EUC-JP, EUC-KR, GB2312, EUC-TW, BIG5, GB18030, SJIS,
+             - UTF-8 (already handled above).
+           Use specialized code for each.  */
+        if (m >= 4 || m >= MB_CUR_MAX)
+          goto invalid;
+        /* Here MB_CUR_MAX > 1 and 0 < m < 4.  */
+        switch (enc)
           {
-            pstate[++k] = s[1];
-            if (k < m)
-              pstate[++k] = s[2];
+          /* As a reference for this code, you can use the GNU libiconv
+             implementation.  Look for uses of the RET_TOOFEW macro.  */
+
+          case enc_eucjp: /* EUC-JP */
+            {
+              if (m == 1)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if ((c >= 0xa1 && c < 0xff) || c == 0x8e || c == 0x8f)
+                    goto incomplete;
+                }
+              if (m == 2)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if (c == 0x8f)
+                    {
+                      unsigned char c2 = (unsigned char) p[1];
+
+                      if (c2 >= 0xa1 && c2 < 0xff)
+                        goto incomplete;
+                    }
+                }
+              goto invalid;
+            }
+
+          case enc_94: /* EUC-KR, GB2312, BIG5 */
+            {
+              if (m == 1)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if (c >= 0xa1 && c < 0xff)
+                    goto incomplete;
+                }
+              goto invalid;
+            }
+
+          case enc_euctw: /* EUC-TW */
+            {
+              if (m == 1)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if ((c >= 0xa1 && c < 0xff) || c == 0x8e)
+                    goto incomplete;
+                }
+              else /* m == 2 || m == 3 */
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if (c == 0x8e)
+                    goto incomplete;
+                }
+              goto invalid;
+            }
+
+          case enc_gb18030: /* GB18030 */
+            {
+              if (m == 1)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if ((c >= 0x90 && c <= 0xe3) || (c >= 0xf8 && c <= 0xfe))
+                    goto incomplete;
+                }
+              else /* m == 2 || m == 3 */
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if (c >= 0x90 && c <= 0xe3)
+                    {
+                      unsigned char c2 = (unsigned char) p[1];
+
+                      if (c2 >= 0x30 && c2 <= 0x39)
+                        {
+                          if (m == 2)
+                            goto incomplete;
+                          else /* m == 3 */
+                            {
+                              unsigned char c3 = (unsigned char) p[2];
+
+                              if (c3 >= 0x81 && c3 <= 0xfe)
+                                goto incomplete;
+                            }
+                        }
+                    }
+                }
+              goto invalid;
+            }
+
+          case enc_sjis: /* SJIS */
+            {
+              if (m == 1)
+                {
+                  unsigned char c = (unsigned char) p[0];
+
+                  if ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xea)
+                      || (c >= 0xf0 && c <= 0xf9))
+                    goto incomplete;
+                }
+              goto invalid;
+            }
+
+          default:
+            /* An unknown multibyte encoding.  */
+            goto incomplete;
           }
-        if (k != m)
-          abort ();
       }
-      pstate[0] = m;
-      return (size_t)(-2);
 
-     invalid:
-      errno = EILSEQ;
-      /* The conversion state is undefined, says POSIX.  */
-      return (size_t)(-1);
+   success:
+    /* res >= 0 is the corrected return value of mbtowc (pwc, p, m).  */
+    if (nstate >= (res > 0 ? res : 1))
+      abort ();
+    res -= nstate;
+    pstate[0] = 0;
+    return res;
+
+   incomplete:
+    {
+      size_t k = nstate;
+      /* Here 0 <= k < m < 4.  */
+      pstate[++k] = s[0];
+      if (k < m)
+        {
+          pstate[++k] = s[1];
+          if (k < m)
+            pstate[++k] = s[2];
+        }
+      if (k != m)
+        abort ();
     }
+    pstate[0] = m;
+    return (size_t)(-2);
+
+   invalid:
+    errno = EILSEQ;
+    /* The conversion state is undefined, says POSIX.  */
+    return (size_t)(-1);
   }
 }