Use faccessat, not access, when checking file permissions.

* .bzrignore: Add lib/fcntl.h.
* configure.ac (euidaccess): Remove check; gnulib does this for us now.
(gl_FCNTL_O_FLAGS): Define a dummy version.
* lib/at-func.c, lib/euidaccess.c, lib/faccessat.c, lib/fcntl.in.h:
* lib/getgroups.c, lib/group-member.c, lib/root-uid.h:
* lib/xalloc-oversized.h, m4/euidaccess.m4, m4/faccessat.m4:
* m4/fcntl_h.m4, m4/getgroups.m4, m4/group-member.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Add faccessat.
(GNULIB_TOOL_FLAGS): Avoid at-internal, fchdir, malloc-posix,
openat-die, openat-h, save-cwd.  Do not avoid fcntl-h.
Omit gnulib's m4/fcntl-o.m4.
* nt/inc/ms-w32.h (AT_FDCWD, AT_EACCESS): New symbols.
(access): Remove.
(faccessat): New macro.
* src/Makefile.in (LIB_EACCESS): New macro.
(LIBES): Use it.
* src/callproc.c (init_callproc):
* src/charset.c (init_charset):
* src/fileio.c (check_existing, check_executable):
* src/lread.c (openp, load_path_check):
* src/process.c (allocate_pty):
* src/xrdb.c (file_p):
Use faccessat, not access or euidaccess.  Use symbolic names
instead of integers for the flags, as they're portable now.
* src/charset.c, src/xrdb.c: Include <fcntl.h>, for the new flags used.
* src/fileio.c (Ffile_readable_p):
Use faccessat, not stat + open + close.
(file_directory_p): New function, which uses 'stat' on most places
but 'access' (for efficiency) if WINDOWSNT.
* src/fileio.c (Ffile_directory_p, Fset_file_times):
* src/xrdb.c (file_p): Use file_directory_p.
* src/lisp.h (file_directory_p): New decl.
* src/lread.c (openp): When opening a file, use fstat rather than
stat, as that avoids a permissions race.  When not opening a file,
use file_directory_p rather than stat.
* src/process.c, src/sysdep.c, src/term.c: All uses of '#ifdef O_NONBLOCK'
changed to '#if O_NONBLOCK', to accommodate gnulib O_* tyle.
* src/w32.c (sys_faccessat): Rename from sys_access and switch to
faccessat's API.  All uses changed.

Fixes: debbugs:12632

21 files changed, 377 insertions, 146 deletions

diff --git a/ChangeLog b/ChangeLog
index 81eddade0a0..c7fcd319af2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2012-10-19  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use faccessat, not access, when checking file permissions (Bug#12632).
+        * .bzrignore: Add lib/fcntl.h.
+        * configure.ac (euidaccess): Remove check; gnulib does this for us now.
+        (gl_FCNTL_O_FLAGS): Define a dummy version.
+        * lib/at-func.c, lib/euidaccess.c, lib/faccessat.c, lib/fcntl.in.h:
+        * lib/getgroups.c, lib/group-member.c, lib/root-uid.h:
+        * lib/xalloc-oversized.h, m4/euidaccess.m4, m4/faccessat.m4:
+        * m4/fcntl_h.m4, m4/getgroups.m4, m4/group-member.m4:
+        New files, from gnulib.
+        * lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
+
 2012-10-18  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * Makefile.in ($(MAKEFILE_NAME)): Depend on src/lisp.mk as well.
diff --git a/admin/ChangeLog b/admin/ChangeLog
index e21293d618d..6d08bf7c37e 100644
--- a/admin/ChangeLog
+++ b/admin/ChangeLog
@@ -1,3 +1,11 @@
+2012-10-19  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use faccessat, not access, when checking file permissions (Bug#12632).
+        * merge-gnulib (GNULIB_MODULES): Add faccessat.
+        (GNULIB_TOOL_FLAGS): Avoid at-internal, fchdir, malloc-posix,
+        openat-die, openat-h, save-cwd.  Do not avoid fcntl-h.
+        Omit gnulib's m4/fcntl-o.m4.
+
 2012-10-12  Kenichi Handa  <handa@gnu.org>
 
         * charsets/Makefile (JISC6226.map): Add missing mappings.
diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 7fc0b5f4844..3c4d8e8058d 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -28,7 +28,7 @@ GNULIB_URL=git://git.savannah.gnu.org/gnulib.git
 GNULIB_MODULES='
   alloca-opt c-ctype c-strcase
   careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512
-  dtoastr dtotimespec dup2 environ execinfo
+  dtoastr dtotimespec dup2 environ execinfo faccessat
   filemode getloadavg getopt-gnu gettime gettimeofday
   ignore-value intprops largefile lstat
   manywarnings mktime pselect pthread_sigmask readlink
@@ -39,9 +39,12 @@ GNULIB_MODULES='
 '
 
 GNULIB_TOOL_FLAGS='
-  --avoid=errno --avoid=fcntl --avoid=fcntl-h --avoid=fstat
-  --avoid=msvc-inval --avoid=msvc-nothrow
-  --avoid=raise --avoid=select --avoid=sigprocmask --avoid=sys_types
+  --avoid=at-internal
+  --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat
+  --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow
+  --avoid=openat-die --avoid=openat-h
+  --avoid=raise
+  --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types
   --avoid=threadlib
   --conditional-dependencies --import --no-changelog --no-vc-files
   --makefile-name=gnulib.mk
@@ -85,7 +88,7 @@ test -x "$gnulib_srcdir"/gnulib-tool || {
 }
 
 "$gnulib_srcdir"/gnulib-tool --dir="$src" $GNULIB_TOOL_FLAGS $GNULIB_MODULES &&
-rm -- "$src"m4/gnulib-cache.m4 "$src"m4/warn-on-use.m4 &&
+rm -- "$src"m4/fcntl-o.m4 "$src"m4/gnulib-cache.m4 "$src"m4/warn-on-use.m4 &&
 cp -- "$gnulib_srcdir"/build-aux/texinfo.tex "$src"doc/misc &&
 cp -- "$gnulib_srcdir"/build-aux/move-if-change "$src"build-aux &&
 autoreconf -i -I m4 -- ${src:+"$src"}
diff --git a/configure.ac b/configure.ac
index 5520dd6a903..6b4c757ced5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -572,6 +572,8 @@ else
   test "x$NON_GCC_TEST_OPTIONS" != x && CC="$CC $NON_GCC_TEST_OPTIONS"
 fi
 
+# Avoid gnulib's tests for O_NOATIME and O_NOFOLLOW, as we don't use them.
+AC_DEFUN([gl_FCNTL_O_FLAGS])
 # Avoid gnulib's threadlib module, as we do threads our own way.
 AC_DEFUN([gl_THREADLIB])
 
@@ -2872,7 +2874,7 @@ AC_SUBST(BLESSMAIL_TARGET)
 AC_CHECK_FUNCS(gethostname \
 closedir getrusage get_current_dir_name \
 lrand48 setsid \
-fpathconf select euidaccess getpagesize setlocale \
+fpathconf select getpagesize setlocale \
 utimes getrlimit setrlimit setpgid getcwd shutdown getaddrinfo \
 __fpending strsignal setitimer \
 sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
diff --git a/lib/gnulib.mk b/lib/gnulib.mk
index 23749331a83..d2562a4dae1 100644
--- a/lib/gnulib.mk
+++ b/lib/gnulib.mk
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=errno --avoid=fcntl --avoid=fcntl-h --avoid=fstat --avoid=msvc-inval --avoid=msvc-nothrow --avoid=raise --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask readlink socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub utimens warnings
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=at-internal --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=openat-die --avoid=openat-h --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask readlink socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub utimens warnings
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -150,6 +150,17 @@ EXTRA_libgnu_a_SOURCES += dup2.c
 
 ## end   gnulib module dup2
 
+## begin gnulib module euidaccess
+
+if gl_GNULIB_ENABLED_euidaccess
+
+endif
+EXTRA_DIST += euidaccess.c
+
+EXTRA_libgnu_a_SOURCES += euidaccess.c
+
+## end   gnulib module euidaccess
+
 ## begin gnulib module execinfo
 
 BUILT_SOURCES += $(EXECINFO_H)
@@ -175,6 +186,50 @@ EXTRA_libgnu_a_SOURCES += execinfo.c
 
 ## end   gnulib module execinfo
 
+## begin gnulib module faccessat
+
+
+EXTRA_DIST += at-func.c faccessat.c
+
+EXTRA_libgnu_a_SOURCES += at-func.c faccessat.c
+
+## end   gnulib module faccessat
+
+## begin gnulib module fcntl-h
+
+BUILT_SOURCES += fcntl.h
+
+# We need the following in order to create <fcntl.h> when the system
+# doesn't have one that works with the given compiler.
+fcntl.h: fcntl.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H)
+        $(AM_V_GEN)rm -f $@-t $@ && \
+        { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+          sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+              -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+              -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+              -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+              -e 's|@''NEXT_FCNTL_H''@|$(NEXT_FCNTL_H)|g' \
+              -e 's/@''GNULIB_FCNTL''@/$(GNULIB_FCNTL)/g' \
+              -e 's/@''GNULIB_NONBLOCKING''@/$(GNULIB_NONBLOCKING)/g' \
+              -e 's/@''GNULIB_OPEN''@/$(GNULIB_OPEN)/g' \
+              -e 's/@''GNULIB_OPENAT''@/$(GNULIB_OPENAT)/g' \
+              -e 's|@''HAVE_FCNTL''@|$(HAVE_FCNTL)|g' \
+              -e 's|@''HAVE_OPENAT''@|$(HAVE_OPENAT)|g' \
+              -e 's|@''REPLACE_FCNTL''@|$(REPLACE_FCNTL)|g' \
+              -e 's|@''REPLACE_OPEN''@|$(REPLACE_OPEN)|g' \
+              -e 's|@''REPLACE_OPENAT''@|$(REPLACE_OPENAT)|g' \
+              -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+              -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
+              -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+              < $(srcdir)/fcntl.in.h; \
+        } > $@-t && \
+        mv $@-t $@
+MOSTLYCLEANFILES += fcntl.h fcntl.h-t
+
+EXTRA_DIST += fcntl.in.h
+
+## end   gnulib module fcntl-h
+
 ## begin gnulib module filemode
 
 libgnu_a_SOURCES += filemode.c
@@ -183,6 +238,17 @@ EXTRA_DIST += filemode.h
 
 ## end   gnulib module filemode
 
+## begin gnulib module getgroups
+
+if gl_GNULIB_ENABLED_getgroups
+
+endif
+EXTRA_DIST += getgroups.c
+
+EXTRA_libgnu_a_SOURCES += getgroups.c
+
+## end   gnulib module getgroups
+
 ## begin gnulib module getloadavg
 
 
@@ -242,6 +308,17 @@ EXTRA_libgnu_a_SOURCES += gettimeofday.c
 
 ## end   gnulib module gettimeofday
 
+## begin gnulib module group-member
+
+if gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1
+
+endif
+EXTRA_DIST += group-member.c
+
+EXTRA_libgnu_a_SOURCES += group-member.c
+
+## end   gnulib module group-member
+
 ## begin gnulib module ignore-value
 
 
@@ -354,6 +431,15 @@ EXTRA_libgnu_a_SOURCES += readlink.c
 
 ## end   gnulib module readlink
 
+## begin gnulib module root-uid
+
+if gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c
+
+endif
+EXTRA_DIST += root-uid.h
+
+## end   gnulib module root-uid
+
 ## begin gnulib module signal-h
 
 BUILT_SOURCES += signal.h
@@ -1312,6 +1398,15 @@ EXTRA_DIST += verify.h
 
 ## end   gnulib module verify
 
+## begin gnulib module xalloc-oversized
+
+if gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec
+
+endif
+EXTRA_DIST += xalloc-oversized.h
+
+## end   gnulib module xalloc-oversized
+
 
 mostlyclean-local: mostlyclean-generic
         @for dir in '' $(MOSTLYCLEANDIRS); do \
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index de2355d87c3..9b2dcee1cfa 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -53,17 +53,22 @@ AC_DEFUN([gl_EARLY],
   # Code from module dtotimespec:
   # Code from module dup2:
   # Code from module environ:
+  # Code from module euidaccess:
   # Code from module execinfo:
   # Code from module extensions:
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   # Code from module extern-inline:
+  # Code from module faccessat:
+  # Code from module fcntl-h:
   # Code from module filemode:
+  # Code from module getgroups:
   # Code from module getloadavg:
   # Code from module getopt-gnu:
   # Code from module getopt-posix:
   # Code from module gettext-h:
   # Code from module gettime:
   # Code from module gettimeofday:
+  # Code from module group-member:
   # Code from module ignore-value:
   # Code from module include_next:
   # Code from module intprops:
@@ -79,6 +84,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module pselect:
   # Code from module pthread_sigmask:
   # Code from module readlink:
+  # Code from module root-uid:
   # Code from module signal-h:
   # Code from module snippet/_Noreturn:
   # Code from module snippet/arg-nonnull:
@@ -120,6 +126,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module utimens:
   # Code from module verify:
   # Code from module warnings:
+  # Code from module xalloc-oversized:
 ])
 
 # This macro should be invoked from ./configure.ac, in the section
@@ -156,6 +163,14 @@ AC_DEFUN([gl_INIT],
   gl_UNISTD_MODULE_INDICATOR([environ])
   gl_EXECINFO_H
   AC_REQUIRE([gl_EXTERN_INLINE])
+  gl_FUNC_FACCESSAT
+  if test $HAVE_FACCESSAT = 0; then
+    AC_LIBOBJ([faccessat])
+    gl_PREREQ_FACCESSAT
+  fi
+  gl_MODULE_INDICATOR([faccessat])
+  gl_UNISTD_MODULE_INDICATOR([faccessat])
+  gl_FCNTL_H
   gl_FILEMODE
   gl_GETLOADAVG
   if test $HAVE_GETLOADAVG = 0; then
@@ -269,18 +284,53 @@ AC_DEFUN([gl_INIT],
   gl_UNISTD_H
   gl_UTIMENS
   gl_gnulib_enabled_dosname=false
+  gl_gnulib_enabled_euidaccess=false
+  gl_gnulib_enabled_getgroups=false
   gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36=false
+  gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=false
   gl_gnulib_enabled_pathmax=false
+  gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
   gl_gnulib_enabled_stat=false
   gl_gnulib_enabled_strtoll=false
   gl_gnulib_enabled_strtoull=false
   gl_gnulib_enabled_verify=false
+  gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
   func_gl_gnulib_m4code_dosname ()
   {
     if ! $gl_gnulib_enabled_dosname; then
       gl_gnulib_enabled_dosname=true
     fi
   }
+  func_gl_gnulib_m4code_euidaccess ()
+  {
+    if ! $gl_gnulib_enabled_euidaccess; then
+      gl_FUNC_EUIDACCESS
+      if test $HAVE_EUIDACCESS = 0; then
+        AC_LIBOBJ([euidaccess])
+        gl_PREREQ_EUIDACCESS
+      fi
+      gl_UNISTD_MODULE_INDICATOR([euidaccess])
+      gl_gnulib_enabled_euidaccess=true
+      if test $HAVE_EUIDACCESS = 0; then
+        func_gl_gnulib_m4code_a9786850e999ae65a836a6041e8e5ed1
+      fi
+      func_gl_gnulib_m4code_6099e9737f757db36c47fa9d9f02e88c
+      if test $HAVE_EUIDACCESS = 0; then
+        func_gl_gnulib_m4code_stat
+      fi
+    fi
+  }
+  func_gl_gnulib_m4code_getgroups ()
+  {
+    if ! $gl_gnulib_enabled_getgroups; then
+      gl_FUNC_GETGROUPS
+      if test $HAVE_GETGROUPS = 0 || test $REPLACE_GETGROUPS = 1; then
+        AC_LIBOBJ([getgroups])
+      fi
+      gl_UNISTD_MODULE_INDICATOR([getgroups])
+      gl_gnulib_enabled_getgroups=true
+    fi
+  }
   func_gl_gnulib_m4code_be453cec5eecf5731a274f2de7f2db36 ()
   {
     if ! $gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36; then
@@ -289,6 +339,24 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36=true
     fi
   }
+  func_gl_gnulib_m4code_a9786850e999ae65a836a6041e8e5ed1 ()
+  {
+    if ! $gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1; then
+      gl_FUNC_GROUP_MEMBER
+      if test $HAVE_GROUP_MEMBER = 0; then
+        AC_LIBOBJ([group-member])
+        gl_PREREQ_GROUP_MEMBER
+      fi
+      gl_UNISTD_MODULE_INDICATOR([group-member])
+      gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=true
+      if test $HAVE_GROUP_MEMBER = 0; then
+        func_gl_gnulib_m4code_getgroups
+      fi
+      if test $HAVE_GROUP_MEMBER = 0; then
+        func_gl_gnulib_m4code_682e609604ccaac6be382e4ee3a4eaec
+      fi
+    fi
+  }
   func_gl_gnulib_m4code_pathmax ()
   {
     if ! $gl_gnulib_enabled_pathmax; then
@@ -296,6 +364,12 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_pathmax=true
     fi
   }
+  func_gl_gnulib_m4code_6099e9737f757db36c47fa9d9f02e88c ()
+  {
+    if ! $gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c; then
+      gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=true
+    fi
+  }
   func_gl_gnulib_m4code_stat ()
   {
     if ! $gl_gnulib_enabled_stat; then
@@ -347,6 +421,18 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_verify=true
     fi
   }
+  func_gl_gnulib_m4code_682e609604ccaac6be382e4ee3a4eaec ()
+  {
+    if ! $gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec; then
+      gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=true
+    fi
+  }
+  if test $HAVE_FACCESSAT = 0; then
+    func_gl_gnulib_m4code_dosname
+  fi
+  if test $HAVE_FACCESSAT = 0; then
+    func_gl_gnulib_m4code_euidaccess
+  fi
   if test $REPLACE_GETOPT = 1; then
     func_gl_gnulib_m4code_be453cec5eecf5731a274f2de7f2db36
   fi
@@ -373,12 +459,17 @@ AC_DEFUN([gl_INIT],
   fi
   m4_pattern_allow([^gl_GNULIB_ENABLED_])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_dosname], [$gl_gnulib_enabled_dosname])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_euidaccess], [$gl_gnulib_enabled_euidaccess])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_getgroups], [$gl_gnulib_enabled_getgroups])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36], [$gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1], [$gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_pathmax], [$gl_gnulib_enabled_pathmax])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_stat], [$gl_gnulib_enabled_stat])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoll], [$gl_gnulib_enabled_strtoll])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoull], [$gl_gnulib_enabled_strtoull])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_verify], [$gl_gnulib_enabled_verify])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec], [$gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec])
   # End of code from modules
   m4_ifval(gl_LIBSOURCES_LIST, [
     m4_syscmd([test ! -d ]m4_defn([gl_LIBSOURCES_DIR])[ ||
@@ -527,6 +618,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/alloca.in.h
   lib/allocator.c
   lib/allocator.h
+  lib/at-func.c
   lib/c-ctype.c
   lib/c-ctype.h
   lib/c-strcase.h
@@ -538,12 +630,16 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/dtoastr.c
   lib/dtotimespec.c
   lib/dup2.c
+  lib/euidaccess.c
   lib/execinfo.c
   lib/execinfo.in.h
+  lib/faccessat.c
+  lib/fcntl.in.h
   lib/filemode.c
   lib/filemode.h
   lib/ftoastr.c
   lib/ftoastr.h
+  lib/getgroups.c
   lib/getloadavg.c
   lib/getopt.c
   lib/getopt.in.h
@@ -552,6 +648,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/gettext.h
   lib/gettime.c
   lib/gettimeofday.c
+  lib/group-member.c
   lib/ignore-value.h
   lib/intprops.h
   lib/inttypes.in.h
@@ -564,6 +661,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/pselect.c
   lib/pthread_sigmask.c
   lib/readlink.c
+  lib/root-uid.h
   lib/sha1.c
   lib/sha1.h
   lib/sha256.c
@@ -605,21 +703,28 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/utimens.c
   lib/utimens.h
   lib/verify.h
+  lib/xalloc-oversized.h
   m4/00gnulib.m4
   m4/alloca.m4
   m4/c-strtod.m4
   m4/clock_time.m4
   m4/dup2.m4
   m4/environ.m4
+  m4/euidaccess.m4
   m4/execinfo.m4
   m4/extensions.m4
   m4/extern-inline.m4
+  m4/faccessat.m4
+  m4/fcntl-o.m4
+  m4/fcntl_h.m4
   m4/filemode.m4
+  m4/getgroups.m4
   m4/getloadavg.m4
   m4/getopt.m4
   m4/gettime.m4
   m4/gettimeofday.m4
   m4/gnulib-common.m4
+  m4/group-member.m4
   m4/include_next.m4
   m4/inttypes.m4
   m4/largefile.m4
diff --git a/nt/ChangeLog b/nt/ChangeLog
index 94d2ce18551..f64cafe2e16 100644
--- a/nt/ChangeLog
+++ b/nt/ChangeLog
@@ -1,3 +1,10 @@
+2012-10-19  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use faccessat, not access, when checking file permissions (Bug#12632).
+        * inc/ms-w32.h (AT_FDCWD, AT_EACCESS): New symbols.
+        (access): Remove.
+        (faccessat): New macro.
+
 2012-10-17  Eli Zaretskii  <eliz@gnu.org>
 
         * inc/pwd.h (getuid, geteuid): Add prototypes.
diff --git a/nt/inc/ms-w32.h b/nt/inc/ms-w32.h
index dd2ae781cb8..0f6b51d3915 100644
--- a/nt/inc/ms-w32.h
+++ b/nt/inc/ms-w32.h
@@ -124,6 +124,10 @@ extern char *getenv ();
 #define MAXPATHLEN      _MAX_PATH
 #endif
 
+/* Use values compatible with gnulib, as there's no reason to differ.  */
+#define AT_FDCWD (-3041965)
+#define AT_EACCESS 4
+
 #ifdef HAVE_NTGUI
 #define HAVE_WINDOW_SYSTEM 1
 #define HAVE_MENUS 1
@@ -145,8 +149,6 @@ extern char *getenv ();
 #endif
 
 /* Calls that are emulated or shadowed.  */
-#undef access
-#define access  sys_access
 #undef chdir
 #define chdir   sys_chdir
 #undef chmod
@@ -161,6 +163,7 @@ extern char *getenv ();
 #define dup     sys_dup
 #undef dup2
 #define dup2    sys_dup2
+#define faccessat  sys_faccessat
 #define fopen   sys_fopen
 #define link    sys_link
 #define localtime sys_localtime
diff --git a/src/ChangeLog b/src/ChangeLog
index 5a1b4a5d8ee..ee18650e992 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,32 @@
+2012-10-19  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use faccessat, not access, when checking file permissions (Bug#12632).
+        * Makefile.in (LIB_EACCESS): New macro.
+        (LIBES): Use it.
+        * callproc.c (init_callproc):
+        * charset.c (init_charset):
+        * fileio.c (check_existing, check_executable):
+        * lread.c (openp, load_path_check):
+        * process.c (allocate_pty):
+        * xrdb.c (file_p):
+        Use faccessat, not access or euidaccess.  Use symbolic names
+        instead of integers for the flags, as they're portable now.
+        * charset.c, xrdb.c: Include <fcntl.h>, for the new flags used.
+        * fileio.c (Ffile_readable_p):
+        Use faccessat, not stat + open + close.
+        (file_directory_p): New function, which uses 'stat' on most places
+        but 'access' (for efficiency) if WINDOWSNT.
+        * fileio.c (Ffile_directory_p, Fset_file_times):
+        * xrdb.c (file_p): Use file_directory_p.
+        * lisp.h (file_directory_p): New decl.
+        * lread.c (openp): When opening a file, use fstat rather than
+        stat, as that avoids a permissions race.  When not opening a file,
+        use file_directory_p rather than stat.
+        * process.c, sysdep.c, term.c: All uses of '#ifdef O_NONBLOCK'
+        changed to '#if O_NONBLOCK', to accommodate gnulib O_* style.
+        * w32.c (sys_faccessat): Rename from sys_access and switch to
+        faccessat's API.  All uses changed.
+
 2012-10-19  Kazuhiro Ito  <kzhr@d1.dion.ne.jp>  (tiny change)
 
         * font.c (Ffont_at): Fix previous change.
diff --git a/src/Makefile.in b/src/Makefile.in
index c24e421bbbc..d034ad04796 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -150,6 +150,7 @@ M17N_FLT_CFLAGS = @M17N_FLT_CFLAGS@
 M17N_FLT_LIBS = @M17N_FLT_LIBS@
 
 LIB_CLOCK_GETTIME=@LIB_CLOCK_GETTIME@
+LIB_EACCESS=@LIB_EACCESS@
 LIB_TIMER_TIME=@LIB_TIMER_TIME@
 
 DBUS_CFLAGS = @DBUS_CFLAGS@
@@ -392,7 +393,7 @@ otherobj= $(TERMCAP_OBJ) $(PRE_ALLOC_OBJ) $(GMALLOC_OBJ) $(RALLOC_OBJ) \
 LIBES = $(LIBS) $(W32_LIBS) $(LIBX_BASE) $(LIBIMAGE) \
    $(LIBX_OTHER) $(LIBSOUND) \
    $(RSVG_LIBS) $(IMAGEMAGICK_LIBS) $(LIB_CLOCK_GETTIME) \
-   $(LIB_TIMER_TIME) $(DBUS_LIBS) \
+   $(LIB_EACCESS) $(LIB_TIMER_TIME) $(DBUS_LIBS) \
    $(LIB_EXECINFO) \
    $(LIBXML2_LIBS) $(LIBGPM) $(LIBRESOLV) $(LIBS_SYSTEM) \
    $(LIBS_TERMCAP) $(GETLOADAVG_LIBS) $(SETTINGS_LIBS) $(LIBSELINUX_LIBS) \
diff --git a/src/callproc.c b/src/callproc.c
index b33882e54c2..5a9b32f08c3 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1597,13 +1597,13 @@ init_callproc (void)
 #endif
     {
       tempdir = Fdirectory_file_name (Vexec_directory);
-      if (access (SSDATA (tempdir), 0) < 0)
+      if (faccessat (AT_FDCWD, SSDATA (tempdir), F_OK, AT_EACCESS) != 0)
         dir_warning ("Warning: arch-dependent data dir (%s) does not exist.\n",
                      Vexec_directory);
     }
 
   tempdir = Fdirectory_file_name (Vdata_directory);
-  if (access (SSDATA (tempdir), 0) < 0)
+  if (faccessat (AT_FDCWD, SSDATA (tempdir), F_OK, AT_EACCESS) != 0)
     dir_warning ("Warning: arch-independent data dir (%s) does not exist.\n",
                  Vdata_directory);
 
diff --git a/src/charset.c b/src/charset.c
index 6b999824dab..fe068e1d3bc 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -28,6 +28,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #define CHARSET_INLINE EXTERN_INLINE
 
+#include <fcntl.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <limits.h>
@@ -2293,7 +2294,7 @@ init_charset (void)
 {
   Lisp_Object tempdir;
   tempdir = Fexpand_file_name (build_string ("charsets"), Vdata_directory);
-  if (access (SSDATA (tempdir), 0) < 0)
+  if (faccessat (AT_FDCWD, SSDATA (tempdir), F_OK, AT_EACCESS) != 0)
     {
       /* This used to be non-fatal (dir_warning), but it should not
          happen, and if it does sooner or later it will cause some
diff --git a/src/conf_post.h b/src/conf_post.h
index aa008107ba6..eade536e6e1 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -169,6 +169,10 @@ extern void _DebPrint (const char *fmt, ...);
 #endif
 #endif
 
+/* Tell gnulib to omit support for openat-related functions having a
+   first argument other than AT_FDCWD.  */
+#define GNULIB_SUPPORT_ONLY_AT_FDCWD
+
 #include <string.h>
 #include <stdlib.h>
 
diff --git a/src/fileio.c b/src/fileio.c
index d47d7dd9e0b..3accb58a3eb 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2425,15 +2425,7 @@ On Unix, this is a name starting with a `/' or a `~'.  */)
 bool
 check_existing (const char *filename)
 {
-#ifdef DOS_NT
-  /* The full emulation of Posix 'stat' is too expensive on
-     DOS/Windows, when all we want to know is whether the file exists.
-     So we use 'access' instead, which is much more lightweight.  */
-  return (access (filename, F_OK) >= 0);
-#else
-  struct stat st;
-  return (stat (filename, &st) >= 0);
-#endif
+  return faccessat (AT_FDCWD, filename, F_OK, AT_EACCESS) == 0;
 }
 
 /* Return true if file FILENAME exists and can be executed.  */
@@ -2441,21 +2433,7 @@ check_existing (const char *filename)
 static bool
 check_executable (char *filename)
 {
-#ifdef DOS_NT
-  struct stat st;
-  if (stat (filename, &st) < 0)
-    return 0;
-  return ((st.st_mode & S_IEXEC) != 0);
-#else /* not DOS_NT */
-#ifdef HAVE_EUIDACCESS
-  return (euidaccess (filename, 1) >= 0);
-#else
-  /* Access isn't quite right because it uses the real uid
-     and we really want to test with the effective uid.
-     But Unix doesn't give us a right way to do it.  */
-  return (access (filename, 1) >= 0);
-#endif
-#endif /* not DOS_NT */
+  return faccessat (AT_FDCWD, filename, X_OK, AT_EACCESS) == 0;
 }
 
 /* Return true if file FILENAME exists and can be written.  */
@@ -2464,15 +2442,16 @@ static bool
 check_writable (const char *filename)
 {
 #ifdef MSDOS
+  /* FIXME: an faccessat implementation should be added to the
+     DOS/Windows ports and this #ifdef branch should be removed.  */
   struct stat st;
   if (stat (filename, &st) < 0)
     return 0;
   return (st.st_mode & S_IWRITE || S_ISDIR (st.st_mode));
 #else /* not MSDOS */
-#ifdef HAVE_EUIDACCESS
-  bool res = (euidaccess (filename, 2) >= 0);
+  bool res = faccessat (AT_FDCWD, filename, W_OK, AT_EACCESS) == 0;
 #ifdef CYGWIN
-  /* euidaccess may have returned failure because Cygwin couldn't
+  /* faccessat may have returned failure because Cygwin couldn't
      determine the file's UID or GID; if so, we return success. */
   if (!res)
     {
@@ -2483,14 +2462,6 @@ check_writable (const char *filename)
     }
 #endif /* CYGWIN */
   return res;
-#else /* not HAVE_EUIDACCESS */
-  /* Access isn't quite right because it uses the real uid
-     and we really want to test with the effective uid.
-     But Unix doesn't give us a right way to do it.
-     Opening with O_WRONLY could work for an ordinary file,
-     but would lose for directories.  */
-  return (access (filename, 2) >= 0);
-#endif /* not HAVE_EUIDACCESS */
 #endif /* not MSDOS */
 }
 
@@ -2547,9 +2518,6 @@ See also `file-exists-p' and `file-attributes'.  */)
 {
   Lisp_Object absname;
   Lisp_Object handler;
-  int desc;
-  int flags;
-  struct stat statbuf;
 
   CHECK_STRING (filename);
   absname = Fexpand_file_name (filename, Qnil);
@@ -2561,31 +2529,8 @@ See also `file-exists-p' and `file-attributes'.  */)
     return call2 (handler, Qfile_readable_p, absname);
 
   absname = ENCODE_FILE (absname);
-
-#if defined (DOS_NT) || defined (macintosh)
-  /* Under MS-DOS, Windows, and Macintosh, open does not work for
-     directories.  */
-  if (access (SDATA (absname), 0) == 0)
-    return Qt;
-  return Qnil;
-#else /* not DOS_NT and not macintosh */
-  flags = O_RDONLY;
-#ifdef O_NONBLOCK
-  /* Opening a fifo without O_NONBLOCK can wait.
-     We don't want to wait.  But we don't want to mess wth O_NONBLOCK
-     except in the case of a fifo, on a system which handles it.  */
-  desc = stat (SSDATA (absname), &statbuf);
-  if (desc < 0)
-    return Qnil;
-  if (S_ISFIFO (statbuf.st_mode))
-    flags |= O_NONBLOCK;
-#endif
-  desc = emacs_open (SSDATA (absname), flags, 0);
-  if (desc < 0)
-    return Qnil;
-  emacs_close (desc);
-  return Qt;
-#endif /* not DOS_NT and not macintosh */
+  return (faccessat (AT_FDCWD, SSDATA (absname), R_OK, AT_EACCESS) == 0
+          ? Qt : Qnil);
 }
 
 /* Having this before file-symlink-p mysteriously caused it to be forgotten
@@ -2622,7 +2567,7 @@ DEFUN ("file-writable-p", Ffile_writable_p, Sfile_writable_p, 1, 1, 0,
   /* The read-only attribute of the parent directory doesn't affect
      whether a file or directory can be created within it.  Some day we
      should check ACLs though, which do affect this.  */
-  return (access (SDATA (dir), D_OK) < 0) ? Qnil : Qt;
+  return file_directory_p (SDATA (dir)) ? Qt : Qnil;
 #else
   return (check_writable (!NILP (dir) ? SSDATA (dir) : "")
           ? Qt : Qnil);
@@ -2703,8 +2648,7 @@ Symbolic links to directories count as directories.
 See `file-symlink-p' to distinguish symlinks.  */)
   (Lisp_Object filename)
 {
-  register Lisp_Object absname;
-  struct stat st;
+  Lisp_Object absname;
   Lisp_Object handler;
 
   absname = expand_and_dir_to_file (filename, BVAR (current_buffer, directory));
@@ -2717,9 +2661,20 @@ See `file-symlink-p' to distinguish symlinks.  */)
 
   absname = ENCODE_FILE (absname);
 
-  if (stat (SSDATA (absname), &st) < 0)
-    return Qnil;
-  return S_ISDIR (st.st_mode) ? Qt : Qnil;
+  return file_directory_p (SSDATA (absname)) ? Qt : Qnil;
+}
+
+/* Return true if FILE is a directory or a symlink to a directory.  */
+bool
+file_directory_p (char const *file)
+{
+#ifdef WINDOWSNT
+  /* This is cheaper than 'stat'.  */
+  return faccessat (AT_FDCWD, file, D_OK, AT_EACCESS) == 0;
+#else
+  struct stat st;
+  return stat (file, &st) == 0 && S_ISDIR (st.st_mode);
+#endif
 }
 
 DEFUN ("file-accessible-directory-p", Ffile_accessible_directory_p,
@@ -3044,10 +2999,8 @@ Use the current time if TIMESTAMP is nil.  TIMESTAMP is in the format of
     if (set_file_times (-1, SSDATA (encoded_absname), t, t))
       {
 #ifdef MSDOS
-        struct stat st;
-
         /* Setting times on a directory always fails.  */
-        if (stat (SSDATA (encoded_absname), &st) == 0 && S_ISDIR (st.st_mode))
+        if (file_directory_p (SSDATA (encoded_absname)))
           return Qnil;
 #endif
         report_file_error ("Setting file times", Fcons (absname, Qnil));
diff --git a/src/lisp.h b/src/lisp.h
index 01f6ca5e57c..897757cf462 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3178,6 +3178,7 @@ extern Lisp_Object close_file_unwind (Lisp_Object);
 extern Lisp_Object restore_point_unwind (Lisp_Object);
 extern _Noreturn void report_file_error (const char *, Lisp_Object);
 extern void internal_delete_file (Lisp_Object);
+extern bool file_directory_p (const char *);
 extern void syms_of_fileio (void);
 extern Lisp_Object make_temp_name (Lisp_Object, bool);
 extern Lisp_Object Qdelete_file;
diff --git a/src/lread.c b/src/lread.c
index 6d4c0d990af..dedce50de2a 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1404,7 +1404,7 @@ Returns the file's name in absolute form, or nil if not found.
 If SUFFIXES is non-nil, it should be a list of suffixes to append to
 file name when searching.
 If non-nil, PREDICATE is used instead of `file-readable-p'.
-PREDICATE can also be an integer to pass to the access(2) function,
+PREDICATE can also be an integer to pass to the faccessat(2) function,
 in which case file-name-handlers are ignored.
 This function will normally skip directories, so if you want it to find
 directories, make sure the PREDICATE function returns `dir-ok' for them.  */)
@@ -1442,7 +1442,6 @@ static Lisp_Object Qdir_ok;
 int
 openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *storeptr, Lisp_Object predicate)
 {
-  int fd;
   ptrdiff_t fn_size = 100;
   char buf[100];
   char *fn = buf;
@@ -1497,7 +1496,6 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
         {
           ptrdiff_t fnlen, lsuffix = SBYTES (XCAR (tail));
           Lisp_Object handler;
-          bool exists;
 
           /* Concatenate path element/specified name with the suffix.
              If the directory starts with /:, remove that.  */
@@ -1521,6 +1519,7 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
           handler = Ffind_file_name_handler (string, Qfile_exists_p);
           if ((!NILP (handler) || !NILP (predicate)) && !NATNUMP (predicate))
             {
+              bool exists;
               if (NILP (predicate))
                 exists = !NILP (Ffile_readable_p (string));
               else
@@ -1542,37 +1541,40 @@ openp (Lisp_Object path, Lisp_Object str, Lisp_Object suffixes, Lisp_Object *sto
             }
           else
             {
-#ifndef WINDOWSNT
-              struct stat st;
-#endif
+              int fd;
               const char *pfn;
 
               encoded_fn = ENCODE_FILE (string);
               pfn = SSDATA (encoded_fn);
-#ifdef WINDOWSNT
-              exists = access (pfn, F_OK) == 0 && access (pfn, D_OK) < 0;
-#else
-              exists = (stat (pfn, &st) == 0 && ! S_ISDIR (st.st_mode));
-#endif
-              if (exists)
-                {
-                  /* Check that we can access or open it.  */
-                  if (NATNUMP (predicate))
-                    fd = (((XFASTINT (predicate) & ~INT_MAX) == 0
-                           && access (pfn, XFASTINT (predicate)) == 0)
-                          ? 1 : -1);
-                  else
-                    fd = emacs_open (pfn, O_RDONLY, 0);
 
-                  if (fd >= 0)
+              /* Check that we can access or open it.  */
+              if (NATNUMP (predicate))
+                fd = (((XFASTINT (predicate) & ~INT_MAX) == 0
+                       && (faccessat (AT_FDCWD, pfn, XFASTINT (predicate),
+                                      AT_EACCESS)
+                           == 0)
+                       && ! file_directory_p (pfn))
+                      ? 1 : -1);
+              else
+                {
+                  struct stat st;
+                  fd = emacs_open (pfn, O_RDONLY, 0);
+                  if (0 <= fd
+                      && (fstat (fd, &st) != 0 || S_ISDIR (st.st_mode)))
                     {
-                      /* We succeeded; return this descriptor and filename.  */
-                      if (storeptr)
-                        *storeptr = string;
-                      UNGCPRO;
-                      return fd;
+                      emacs_close (fd);
+                      fd = -1;
                     }
                 }
+
+              if (fd >= 0)
+                {
+                  /* We succeeded; return this descriptor and filename.  */
+                  if (storeptr)
+                    *storeptr = string;
+                  UNGCPRO;
+                  return fd;
+                }
             }
         }
       if (absolute)
@@ -4088,7 +4090,7 @@ load_path_check (void)
       if (STRINGP (dirfile))
         {
           dirfile = Fdirectory_file_name (dirfile);
-          if (access (SSDATA (dirfile), 0) < 0)
+          if (faccessat (AT_FDCWD, SSDATA (dirfile), F_OK, AT_EACCESS) != 0)
             dir_warning ("Warning: Lisp directory `%s' does not exist.\n",
                          XCAR (path_tail));
         }
diff --git a/src/process.c b/src/process.c
index 307e82819d6..572ab83de09 100644
--- a/src/process.c
+++ b/src/process.c
@@ -204,7 +204,7 @@ static EMACS_INT update_tick;
 #ifndef NON_BLOCKING_CONNECT
 #ifdef HAVE_SELECT
 #if defined (HAVE_GETPEERNAME) || defined (GNU_LINUX)
-#if defined (O_NONBLOCK) || defined (O_NDELAY)
+#if O_NONBLOCK || O_NDELAY
 #if defined (EWOULDBLOCK) || defined (EINPROGRESS)
 #define NON_BLOCKING_CONNECT
 #endif /* EWOULDBLOCK || EINPROGRESS */
@@ -651,7 +651,7 @@ allocate_pty (void)
         PTY_OPEN;
 #else /* no PTY_OPEN */
         {
-#  ifdef O_NONBLOCK
+#  if O_NONBLOCK
           fd = emacs_open (pty_name, O_RDWR | O_NONBLOCK, 0);
 #  else
           fd = emacs_open (pty_name, O_RDWR | O_NDELAY, 0);
@@ -668,7 +668,7 @@ allocate_pty (void)
 #else
             sprintf (pty_name, "/dev/tty%c%x", c, i);
 #endif /* no PTY_TTY_NAME_SPRINTF */
-            if (access (pty_name, 6) != 0)
+            if (faccessat (AT_FDCWD, pty_name, R_OK | W_OK, AT_EACCESS) != 0)
               {
                 emacs_close (fd);
 # ifndef __sgi
@@ -1621,7 +1621,7 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #if ! defined (USG) || defined (USG_SUBTTY_WORKS)
       /* On most USG systems it does not work to open the pty's tty here,
          then close it and reopen it in the child.  */
-#ifdef O_NOCTTY
+#if O_NOCTTY
       /* Don't let this terminal become our controlling terminal
          (in case we don't have one).  */
       forkout = forkin = emacs_open (pty_name, O_RDWR | O_NOCTTY, 0);
@@ -1675,11 +1675,11 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
     }
 #endif
 
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
   fcntl (inchannel, F_SETFL, O_NONBLOCK);
   fcntl (outchannel, F_SETFL, O_NONBLOCK);
 #else
-#ifdef O_NDELAY
+#if O_NDELAY
   fcntl (inchannel, F_SETFL, O_NDELAY);
   fcntl (outchannel, F_SETFL, O_NDELAY);
 #endif
@@ -1967,7 +1967,7 @@ create_pty (Lisp_Object process)
 #if ! defined (USG) || defined (USG_SUBTTY_WORKS)
       /* On most USG systems it does not work to open the pty's tty here,
          then close it and reopen it in the child.  */
-#ifdef O_NOCTTY
+#if O_NOCTTY
       /* Don't let this terminal become our controlling terminal
          (in case we don't have one).  */
       int forkout = emacs_open (pty_name, O_RDWR | O_NOCTTY, 0);
@@ -1987,11 +1987,11 @@ create_pty (Lisp_Object process)
     }
 #endif /* HAVE_PTYS */
 
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
   fcntl (inchannel, F_SETFL, O_NONBLOCK);
   fcntl (outchannel, F_SETFL, O_NONBLOCK);
 #else
-#ifdef O_NDELAY
+#if O_NDELAY
   fcntl (inchannel, F_SETFL, O_NDELAY);
   fcntl (outchannel, F_SETFL, O_NDELAY);
 #endif
@@ -2951,7 +2951,7 @@ usage: (make-network-process &rest ARGS)  */)
     {
       /* Don't support network sockets when non-blocking mode is
          not available, since a blocked Emacs is not useful.  */
-#if !defined (O_NONBLOCK) && !defined (O_NDELAY)
+#if !O_NONBLOCK && !O_NDELAY
       error ("Network servers not supported");
 #else
       is_server = 1;
@@ -3217,7 +3217,7 @@ usage: (make-network-process &rest ARGS)  */)
 #ifdef NON_BLOCKING_CONNECT
       if (is_non_blocking_client)
         {
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
           ret = fcntl (s, F_SETFL, O_NONBLOCK);
 #else
           ret = fcntl (s, F_SETFL, O_NDELAY);
@@ -3434,10 +3434,10 @@ usage: (make-network-process &rest ARGS)  */)
 
   chan_process[inch] = proc;
 
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
   fcntl (inch, F_SETFL, O_NONBLOCK);
 #else
-#ifdef O_NDELAY
+#if O_NDELAY
   fcntl (inch, F_SETFL, O_NDELAY);
 #endif
 #endif
@@ -4169,10 +4169,10 @@ server_accept_connection (Lisp_Object server, int channel)
 
   chan_process[s] = proc;
 
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
   fcntl (s, F_SETFL, O_NONBLOCK);
 #else
-#ifdef O_NDELAY
+#if O_NDELAY
   fcntl (s, F_SETFL, O_NDELAY);
 #endif
 #endif
@@ -4873,11 +4873,11 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 #endif
               /* ISC 4.1 defines both EWOULDBLOCK and O_NONBLOCK,
                  and Emacs uses O_NONBLOCK, so what we get is EAGAIN.  */
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
               else if (nread == -1 && errno == EAGAIN)
                 ;
 #else
-#ifdef O_NDELAY
+#if O_NDELAY
               else if (nread == -1 && errno == EAGAIN)
                 ;
               /* Note that we cannot distinguish between no input
@@ -7363,7 +7363,7 @@ init_process_emacs (void)
 #ifdef HAVE_GETSOCKNAME
    ADD_SUBFEATURE (QCservice, Qt);
 #endif
-#if defined (O_NONBLOCK) || defined (O_NDELAY)
+#if O_NONBLOCK || O_NDELAY
    ADD_SUBFEATURE (QCserver, Qt);
 #endif
 
diff --git a/src/sysdep.c b/src/sysdep.c
index 35beeaa7202..8a31957d182 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1216,7 +1216,7 @@ reset_sys_modes (struct tty_display_info *tty_out)
              old_fcntl_owner[fileno (tty_out->input)]);
     }
 #endif /* F_SETOWN */
-#ifdef O_NDELAY
+#if O_NDELAY
   fcntl (fileno (tty_out->input), F_SETFL,
          fcntl (fileno (tty_out->input), F_GETFL, 0) & ~O_NDELAY);
 #endif
@@ -2312,12 +2312,12 @@ serial_open (char *port)
 
   fd = emacs_open ((char*) port,
                    O_RDWR
-#ifdef O_NONBLOCK
+#if O_NONBLOCK
                    | O_NONBLOCK
 #else
                    | O_NDELAY
 #endif
-#ifdef O_NOCTTY
+#if O_NOCTTY
                    | O_NOCTTY
 #endif
                    , 0);
diff --git a/src/term.c b/src/term.c
index f7c87b7608d..87ce5447b76 100644
--- a/src/term.c
+++ b/src/term.c
@@ -3023,7 +3023,7 @@ init_tty (const char *name, const char *terminal_type, int must_succeed)
     int fd;
     FILE *file;
 
-#ifdef O_IGNORE_CTTY
+#if O_IGNORE_CTTY
     if (!ctty)
       /* Open the terminal device.  Don't recognize it as our
          controlling terminal, and don't make it the controlling tty
@@ -3054,7 +3054,7 @@ init_tty (const char *name, const char *terminal_type, int must_succeed)
                      name);
       }
 
-#ifndef O_IGNORE_CTTY
+#if !O_IGNORE_CTTY
     if (!ctty)
       dissociate_if_controlling_tty (fd);
 #endif
diff --git a/src/w32.c b/src/w32.c
index 5ac1bc3eb7c..341f4d3fef3 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1597,7 +1597,7 @@ init_environment (char ** argv)
          see if it succeeds.  But I think that's too much to ask.  */
 
       /* MSVCRT's _access crashes with D_OK.  */
-      if (tmp && sys_access (tmp, D_OK) == 0)
+      if (tmp && sys_faccessat (AT_FDCWD, tmp, D_OK, AT_EACCESS) == 0)
         {
           char * var = alloca (strlen (tmp) + 8);
           sprintf (var, "TMPDIR=%s", tmp);
@@ -2714,10 +2714,16 @@ logon_network_drive (const char *path)
    long file names.  */
 
 int
-sys_access (const char * path, int mode)
+sys_faccessat (int dirfd, const char * path, int mode, int flags)
 {
   DWORD attributes;
 
+  if (dirfd != AT_FDCWD)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
   /* MSVCRT implementation of 'access' doesn't recognize D_OK, and its
      newer versions blow up when passed D_OK.  */
   path = map_w32_filename (path, NULL);
@@ -2960,7 +2966,7 @@ sys_mktemp (char * template)
         {
           int save_errno = errno;
           p[0] = first_char[i];
-          if (sys_access (template, 0) < 0)
+          if (sys_faccessat (AT_FDCWD, template, F_OK, AT_EACCESS) < 0)
             {
               errno = save_errno;
               return template;
@@ -4011,7 +4017,7 @@ symlink (char const *filename, char const *linkname)
     {
       /* Non-absolute FILENAME is understood as being relative to
          LINKNAME's directory.  We need to prepend that directory to
-         FILENAME to get correct results from sys_access below, since
+         FILENAME to get correct results from sys_faccessat below, since
          otherwise it will interpret FILENAME relative to the
          directory where the Emacs process runs.  Note that
          make-symbolic-link always makes sure LINKNAME is a fully
@@ -4025,10 +4031,10 @@ symlink (char const *filename, char const *linkname)
         strncpy (tem, linkfn, p - linkfn);
       tem[p - linkfn] = '\0';
       strcat (tem, filename);
-      dir_access = sys_access (tem, D_OK);
+      dir_access = sys_faccessat (AT_FDCWD, tem, D_OK, AT_EACCESS);
     }
   else
-    dir_access = sys_access (filename, D_OK);
+    dir_access = sys_faccessat (AT_FDCWD, filename, D_OK, AT_EACCESS);
 
   /* Since Windows distinguishes between symlinks to directories and
      to files, we provide a kludgy feature: if FILENAME doesn't
diff --git a/src/xrdb.c b/src/xrdb.c
index 9d056a607e4..982a6e46a13 100644
--- a/src/xrdb.c
+++ b/src/xrdb.c
@@ -21,6 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
+#include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <epaths.h>
@@ -261,11 +262,8 @@ gethomedir (void)
 static int
 file_p (const char *filename)
 {
-  struct stat status;
-
-  return (access (filename, 4) == 0             /* exists and is readable */
-          && stat (filename, &status) == 0      /* get the status */
-          && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
+  return (faccessat (AT_FDCWD, filename, R_OK, AT_EACCESS) == 0
+          && ! file_directory_p (filename));
 }