Fix locating pdump by symlink

* admin/merge-gnulib (GNULIB_MODULES): Add canonicalize-lgpl module
* build-aux/config.guess, build-aux/gitlog-to-changelog,
build-aux/update-copyright, lib/canonicalize-lgpl.c,
lib/gnulib.mk.in, lib/malloca.c, lib/malloca.h, lib/pathmax.h,
m4/canonicalize.m4, m4/double-slash-root.m4, m4/gnulib-comp.m4,
m4/malloca.m4, my/pathmax.4: copy from GNUlib or regenerate from
update
* src/emacs.c: find dump by canonical path

15 files changed, 1130 insertions, 32 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index c2d9291b843..78e74882f3d 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -29,6 +29,7 @@ GNULIB_MODULES='
   alloca-opt binary-io byteswap c-ctype c-strcase
   careadlinkat close-stream copy-file-range
   count-leading-zeros count-one-bits count-trailing-zeros
+  canonicalize-lgpl
   crypto/md5-buffer crypto/sha1-buffer crypto/sha256-buffer crypto/sha512-buffer
   d-type diffseq dosname dtoastr dtotimespec dup2
   environ execinfo explicit_bzero faccessat
diff --git a/build-aux/config.guess b/build-aux/config.guess
index ae713942d8f..41b8b854c02 100755
--- a/build-aux/config.guess
+++ b/build-aux/config.guess
@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2019 Free Software Foundation, Inc.
 
-timestamp='2019-05-28'
+timestamp='2019-06-10'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -262,6 +262,9 @@ case "$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
     *:SolidBSD:*:*)
 	echo "$UNAME_MACHINE"-unknown-solidbsd"$UNAME_RELEASE"
 	exit ;;
+    *:OS108:*:*)
+	echo "$UNAME_MACHINE"-unknown-os108_"$UNAME_RELEASE"
+	exit ;;
     macppc:MirBSD:*:*)
 	echo powerpc-unknown-mirbsd"$UNAME_RELEASE"
 	exit ;;
diff --git a/build-aux/gitlog-to-changelog b/build-aux/gitlog-to-changelog
index deddef24466..3acfa8b4c5b 100755
--- a/build-aux/gitlog-to-changelog
+++ b/build-aux/gitlog-to-changelog
@@ -1,31 +1,46 @@
-eval '(exit $?0)' && eval 'exec perl -wS "$0" "$@"'
-  & eval 'exec perl -wS "$0" $argv:q'
-    if 0;
-# Convert git log output to ChangeLog format.
+#!/bin/sh
+#! -*-perl-*-
 
-my $VERSION = '2018-03-07 03:47'; # UTC
-# The definition above must lie within the first 8 lines in order
-# for the Emacs time-stamp write hook (at end) to update it.
-# If you change this file with Emacs, please let the write hook
-# do its job.  Otherwise, update this string manually.
+# Convert git log output to ChangeLog format.
 
 # Copyright (C) 2008-2019 Free Software Foundation, Inc.
-
+#
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
-
+#
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # 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 <https://www.gnu.org/licenses/>.
-
+#
 # Written by Jim Meyering
 
+# This is a prologue that allows to run a perl script as an executable
+# on systems that are compliant to a POSIX version before POSIX:2017.
+# On such systems, the usual invocation of an executable through execlp()
+# or execvp() fails with ENOEXEC if it is a script that does not start
+# with a #! line.  The script interpreter mentioned in the #! line has
+# to be /bin/sh, because on GuixSD systems that is the only program that
+# has a fixed file name.  The second line is essential for perl and is
+# also useful for editing this file in Emacs.  The next two lines below
+# are valid code in both sh and perl.  When executed by sh, they re-execute
+# the script through the perl program found in $PATH.  The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh.  When executed by  perl, the next two lines are a no-op.
+eval 'exec perl -wSx "$0" "$@"'
+     if 0;
+
+my $VERSION = '2018-03-07 03:47'; # UTC
+# The definition above must lie within the first 8 lines in order
+# for the Emacs time-stamp write hook (at end) to update it.
+# If you change this file with Emacs, please let the write hook
+# do its job.  Otherwise, update this string manually.
+
 use strict;
 use warnings;
 use Getopt::Long;
@@ -492,6 +507,7 @@ sub git_dir_option($)
 # mode: perl
 # indent-tabs-mode: nil
 # eval: (add-hook 'before-save-hook 'time-stamp)
+# time-stamp-line-limit: 50
 # time-stamp-start: "my $VERSION = '"
 # time-stamp-format: "%:y-%02m-%02d %02H:%02M"
 # time-stamp-time-zone: "UTC0"
diff --git a/build-aux/update-copyright b/build-aux/update-copyright
index d80549ea8dd..4a9ea7c7a75 100755
--- a/build-aux/update-copyright
+++ b/build-aux/update-copyright
@@ -1,9 +1,7 @@
-eval '(exit $?0)' && eval 'exec perl -wS -0777 -pi "$0" "$@"'
-  & eval 'exec perl -wS -0777 -pi "$0" $argv:q'
-    if 0;
-# Update an FSF copyright year list to include the current year.
+#!/bin/sh
+#! -*-perl-*-
 
-my $VERSION = '2018-03-07.03:47'; # UTC
+# Update an FSF copyright year list to include the current year.
 
 # Copyright (C) 2009-2019 Free Software Foundation, Inc.
 #
@@ -19,9 +17,12 @@ my $VERSION = '2018-03-07.03:47'; # UTC
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
+#
 # Written by Jim Meyering and Joel E. Denny
 
+# This script updates an FSF copyright year list to include the current year.
+# Usage: update-copyright [FILE...]
+#
 # The arguments to this script should be names of files that contain
 # copyright statements to be updated.  The copyright holder's name
 # defaults to "Free Software Foundation, Inc." but may be changed to
@@ -121,6 +122,27 @@ my $VERSION = '2018-03-07.03:47'; # UTC
 #   5. Set UPDATE_COPYRIGHT_HOLDER if the copyright holder is other
 #      than "Free Software Foundation, Inc.".
 
+# This is a prologue that allows to run a perl script as an executable
+# on systems that are compliant to a POSIX version before POSIX:2017.
+# On such systems, the usual invocation of an executable through execlp()
+# or execvp() fails with ENOEXEC if it is a script that does not start
+# with a #! line.  The script interpreter mentioned in the #! line has
+# to be /bin/sh, because on GuixSD systems that is the only program that
+# has a fixed file name.  The second line is essential for perl and is
+# also useful for editing this file in Emacs.  The next two lines below
+# are valid code in both sh and perl.  When executed by sh, they re-execute
+# the script through the perl program found in $PATH.  The '-x' option
+# is essential as well; without it, perl would re-execute the script
+# through /bin/sh.  When executed by  perl, the next two lines are a no-op.
+eval 'exec perl -wSx "$0" "$@"'
+     if 0;
+
+my $VERSION = '2018-03-07.03:47'; # UTC
+# The definition above must lie within the first 8 lines in order
+# for the Emacs time-stamp write hook (at end) to update it.
+# If you change this file with Emacs, please let the write hook
+# do its job.  Otherwise, update this string manually.
+
 use strict;
 use warnings;
 
@@ -270,6 +292,7 @@ else
 # mode: perl
 # indent-tabs-mode: nil
 # eval: (add-hook 'before-save-hook 'time-stamp)
+# time-stamp-line-limit: 200
 # time-stamp-start: "my $VERSION = '"
 # time-stamp-format: "%:y-%02m-%02d.%02H:%02M"
 # time-stamp-time-zone: "UTC0"
diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
new file mode 100644
index 00000000000..4d1be6dc24b
--- /dev/null
+++ b/lib/canonicalize-lgpl.c
@@ -0,0 +1,428 @@
+/* Return the canonical absolute name of a given file.
+   Copyright (C) 1996-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC
+/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
+   optimizes away the name == NULL test below.  */
+# define _GL_ARG_NONNULL(params)
+
+# define _GL_USE_STDLIB_ALLOC 1
+# include <config.h>
+#endif
+
+#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <alloca.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#if HAVE_SYS_PARAM_H || defined _LIBC
+# include <sys/param.h>
+#endif
+#include <sys/stat.h>
+#include <errno.h>
+#include <stddef.h>
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+#else
+# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
+# define versioned_symbol(lib, local, symbol, version) extern int dummy
+# define compat_symbol(lib, local, symbol, version)
+# define weak_alias(local, symbol)
+# define __canonicalize_file_name canonicalize_file_name
+# define __realpath realpath
+# include "pathmax.h"
+# include "malloca.h"
+# include "dosname.h"
+# if HAVE_GETCWD
+#  if IN_RELOCWRAPPER
+    /* When building the relocatable program wrapper, use the system's getcwd
+       function, not the gnulib override, otherwise we would get a link error.
+     */
+#   undef getcwd
+#  endif
+#  if defined VMS && !defined getcwd
+    /* We want the directory in Unix syntax, not in VMS syntax.
+       The gnulib override of 'getcwd' takes 2 arguments; the original VMS
+       'getcwd' takes 3 arguments.  */
+#   define __getcwd(buf, max) getcwd (buf, max, 0)
+#  else
+#   define __getcwd getcwd
+#  endif
+# else
+#  define __getcwd(buf, max) getwd (buf)
+# endif
+# define __readlink readlink
+# define __set_errno(e) errno = (e)
+# ifndef MAXSYMLINKS
+#  ifdef SYMLOOP_MAX
+#   define MAXSYMLINKS SYMLOOP_MAX
+#  else
+#   define MAXSYMLINKS 20
+#  endif
+# endif
+#endif
+
+#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
+# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
+#endif
+
+/* Define this independently so that stdint.h is not a prerequisite.  */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#if !FUNC_REALPATH_WORKS || defined _LIBC
+
+static void
+alloc_failed (void)
+{
+#if defined _WIN32 && ! defined __CYGWIN__
+  /* Avoid errno problem without using the malloc or realloc modules; see:
+     https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html  */
+  errno = ENOMEM;
+#endif
+}
+
+/* Return the canonical absolute name of file NAME.  A canonical name
+   does not contain any ".", ".." components nor any repeated path
+   separators ('/') or symlinks.  All path components must exist.  If
+   RESOLVED is null, the result is malloc'd; otherwise, if the
+   canonical name is PATH_MAX chars or more, returns null with 'errno'
+   set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
+   returns the name in RESOLVED.  If the name cannot be resolved and
+   RESOLVED is non-NULL, it contains the path of the first component
+   that cannot be resolved.  If the path can be resolved, RESOLVED
+   holds the same value as the value returned.  */
+
+char *
+__realpath (const char *name, char *resolved)
+{
+  char *rpath, *dest, *extra_buf = NULL;
+  const char *start, *end, *rpath_limit;
+  long int path_max;
+  int num_links = 0;
+  size_t prefix_len;
+
+  if (name == NULL)
+    {
+      /* As per Single Unix Specification V2 we must return an error if
+         either parameter is a null pointer.  We extend this to allow
+         the RESOLVED parameter to be NULL in case the we are expected to
+         allocate the room for the return value.  */
+      __set_errno (EINVAL);
+      return NULL;
+    }
+
+  if (name[0] == '\0')
+    {
+      /* As per Single Unix Specification V2 we must return an error if
+         the name argument points to an empty string.  */
+      __set_errno (ENOENT);
+      return NULL;
+    }
+
+#ifdef PATH_MAX
+  path_max = PATH_MAX;
+#else
+  path_max = pathconf (name, _PC_PATH_MAX);
+  if (path_max <= 0)
+    path_max = 8192;
+#endif
+
+  if (resolved == NULL)
+    {
+      rpath = malloc (path_max);
+      if (rpath == NULL)
+        {
+          alloc_failed ();
+          return NULL;
+        }
+    }
+  else
+    rpath = resolved;
+  rpath_limit = rpath + path_max;
+
+  /* This is always zero for Posix hosts, but can be 2 for MS-Windows
+     and MS-DOS X:/foo/bar file names.  */
+  prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
+
+  if (!IS_ABSOLUTE_FILE_NAME (name))
+    {
+      if (!__getcwd (rpath, path_max))
+        {
+          rpath[0] = '\0';
+          goto error;
+        }
+      dest = strchr (rpath, '\0');
+      start = name;
+      prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath);
+    }
+  else
+    {
+      dest = rpath;
+      if (prefix_len)
+        {
+          memcpy (rpath, name, prefix_len);
+          dest += prefix_len;
+        }
+      *dest++ = '/';
+      if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
+        {
+          if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
+            *dest++ = '/';
+          *dest = '\0';
+        }
+      start = name + prefix_len;
+    }
+
+  for (end = start; *start; start = end)
+    {
+#ifdef _LIBC
+      struct stat64 st;
+#else
+      struct stat st;
+#endif
+
+      /* Skip sequence of multiple path-separators.  */
+      while (ISSLASH (*start))
+        ++start;
+
+      /* Find end of path component.  */
+      for (end = start; *end && !ISSLASH (*end); ++end)
+        /* Nothing.  */;
+
+      if (end - start == 0)
+        break;
+      else if (end - start == 1 && start[0] == '.')
+        /* nothing */;
+      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
+        {
+          /* Back up to previous component, ignore if at root already.  */
+          if (dest > rpath + prefix_len + 1)
+            for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
+              continue;
+          if (DOUBLE_SLASH_IS_DISTINCT_ROOT
+              && dest == rpath + 1 && !prefix_len
+              && ISSLASH (*dest) && !ISSLASH (dest[1]))
+            dest++;
+        }
+      else
+        {
+          size_t new_size;
+
+          if (!ISSLASH (dest[-1]))
+            *dest++ = '/';
+
+          if (dest + (end - start) >= rpath_limit)
+            {
+              ptrdiff_t dest_offset = dest - rpath;
+              char *new_rpath;
+
+              if (resolved)
+                {
+                  __set_errno (ENAMETOOLONG);
+                  if (dest > rpath + prefix_len + 1)
+                    dest--;
+                  *dest = '\0';
+                  goto error;
+                }
+              new_size = rpath_limit - rpath;
+              if (end - start + 1 > path_max)
+                new_size += end - start + 1;
+              else
+                new_size += path_max;
+              new_rpath = (char *) realloc (rpath, new_size);
+              if (new_rpath == NULL)
+                {
+                  alloc_failed ();
+                  goto error;
+                }
+              rpath = new_rpath;
+              rpath_limit = rpath + new_size;
+
+              dest = rpath + dest_offset;
+            }
+
+#ifdef _LIBC
+          dest = __mempcpy (dest, start, end - start);
+#else
+          memcpy (dest, start, end - start);
+          dest += end - start;
+#endif
+          *dest = '\0';
+
+          /* FIXME: if lstat fails with errno == EOVERFLOW,
+             the entry exists.  */
+#ifdef _LIBC
+          if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
+#else
+          if (lstat (rpath, &st) < 0)
+#endif
+            goto error;
+
+          if (S_ISLNK (st.st_mode))
+            {
+              char *buf;
+              size_t len;
+              ssize_t n;
+
+              if (++num_links > MAXSYMLINKS)
+                {
+                  __set_errno (ELOOP);
+                  goto error;
+                }
+
+              buf = malloca (path_max);
+              if (!buf)
+                {
+                  __set_errno (ENOMEM);
+                  goto error;
+                }
+
+              n = __readlink (rpath, buf, path_max - 1);
+              if (n < 0)
+                {
+                  int saved_errno = errno;
+                  freea (buf);
+                  __set_errno (saved_errno);
+                  goto error;
+                }
+              buf[n] = '\0';
+
+              if (!extra_buf)
+                {
+                  extra_buf = malloca (path_max);
+                  if (!extra_buf)
+                    {
+                      freea (buf);
+                      __set_errno (ENOMEM);
+                      goto error;
+                    }
+                }
+
+              len = strlen (end);
+              /* Check that n + len + 1 doesn't overflow and is <= path_max. */
+              if (n >= SIZE_MAX - len || n + len >= path_max)
+                {
+                  freea (buf);
+                  __set_errno (ENAMETOOLONG);
+                  goto error;
+                }
+
+              /* Careful here, end may be a pointer into extra_buf... */
+              memmove (&extra_buf[n], end, len + 1);
+              name = end = memcpy (extra_buf, buf, n);
+
+              if (IS_ABSOLUTE_FILE_NAME (buf))
+                {
+                  size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
+
+                  if (pfxlen)
+                    memcpy (rpath, buf, pfxlen);
+                  dest = rpath + pfxlen;
+                  *dest++ = '/'; /* It's an absolute symlink */
+                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
+                    {
+                      if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
+                        *dest++ = '/';
+                      *dest = '\0';
+                    }
+                  /* Install the new prefix to be in effect hereafter.  */
+                  prefix_len = pfxlen;
+                }
+              else
+                {
+                  /* Back up to previous component, ignore if at root
+                     already: */
+                  if (dest > rpath + prefix_len + 1)
+                    for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
+                      continue;
+                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
+                      && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
+                    dest++;
+                }
+            }
+          else if (!S_ISDIR (st.st_mode) && *end != '\0')
+            {
+              __set_errno (ENOTDIR);
+              goto error;
+            }
+        }
+    }
+  if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1]))
+    --dest;
+  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len
+      && ISSLASH (*dest) && !ISSLASH (dest[1]))
+    dest++;
+  *dest = '\0';
+
+  if (extra_buf)
+    freea (extra_buf);
+
+  return rpath;
+
+error:
+  {
+    int saved_errno = errno;
+    if (extra_buf)
+      freea (extra_buf);
+    if (resolved == NULL)
+      free (rpath);
+    __set_errno (saved_errno);
+  }
+  return NULL;
+}
+versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
+#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */
+
+
+#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
+char *
+attribute_compat_text_section
+__old_realpath (const char *name, char *resolved)
+{
+  if (resolved == NULL)
+    {
+      __set_errno (EINVAL);
+      return NULL;
+    }
+
+  return __realpath (name, resolved);
+}
+compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
+#endif
+
+
+char *
+__canonicalize_file_name (const char *name)
+{
+  return __realpath (name, NULL);
+}
+weak_alias (__canonicalize_file_name, canonicalize_file_name)
+
+#else
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;
+
+#endif
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 6e817fa6897..d0bef0bd5de 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -72,6 +72,7 @@
 #  byteswap \
 #  c-ctype \
 #  c-strcase \
+#  canonicalize-lgpl \
 #  careadlinkat \
 #  close-stream \
 #  copy-file-range \
@@ -484,6 +485,8 @@ GTK_CFLAGS = @GTK_CFLAGS@
 GTK_LIBS = @GTK_LIBS@
 GTK_OBJ = @GTK_OBJ@
 GZIP_PROG = @GZIP_PROG@
+HARFBUZZ_CFLAGS = @HARFBUZZ_CFLAGS@
+HARFBUZZ_LIBS = @HARFBUZZ_LIBS@
 HAVE_ALLOCA_H = @HAVE_ALLOCA_H@
 HAVE_ALPHASORT = @HAVE_ALPHASORT@
 HAVE_ATOLL = @HAVE_ATOLL@
@@ -1105,6 +1108,7 @@ pdfdir = @pdfdir@
 prefix = @prefix@
 program_transform_name = @program_transform_name@
 psdir = @psdir@
+runstatedir = @runstatedir@
 sbindir = @sbindir@
 sharedstatedir = @sharedstatedir@
 srcdir = @srcdir@
@@ -1243,6 +1247,17 @@ libgnu_a_SOURCES += c-strcase.h c-strcasecmp.c c-strncasecmp.c
 endif
 ## end   gnulib module c-strcase
 
+## begin gnulib module canonicalize-lgpl
+ifeq (,$(OMIT_GNULIB_MODULE_canonicalize-lgpl))
+
+
+EXTRA_DIST += canonicalize-lgpl.c
+
+EXTRA_libgnu_a_SOURCES += canonicalize-lgpl.c
+
+endif
+## end   gnulib module canonicalize-lgpl
+
 ## begin gnulib module careadlinkat
 ifeq (,$(OMIT_GNULIB_MODULE_careadlinkat))
 
@@ -1980,6 +1995,18 @@ EXTRA_libgnu_a_SOURCES += lstat.c
 endif
 ## end   gnulib module lstat
 
+## begin gnulib module malloca
+ifeq (,$(OMIT_GNULIB_MODULE_malloca))
+
+ifneq (,$(gl_GNULIB_ENABLED_malloca))
+libgnu_a_SOURCES += malloca.c
+
+endif
+EXTRA_DIST += malloca.h
+
+endif
+## end   gnulib module malloca
+
 ## begin gnulib module memmem-simple
 ifeq (,$(OMIT_GNULIB_MODULE_memmem-simple))
 
@@ -2079,6 +2106,17 @@ EXTRA_DIST += openat.h
 endif
 ## end   gnulib module openat-h
 
+## begin gnulib module pathmax
+ifeq (,$(OMIT_GNULIB_MODULE_pathmax))
+
+ifneq (,$(gl_GNULIB_ENABLED_pathmax))
+
+endif
+EXTRA_DIST += pathmax.h
+
+endif
+## end   gnulib module pathmax
+
 ## begin gnulib module pipe2
 ifeq (,$(OMIT_GNULIB_MODULE_pipe2))
 
diff --git a/lib/malloca.c b/lib/malloca.c
new file mode 100644
index 00000000000..f60c5fb5d93
--- /dev/null
+++ b/lib/malloca.c
@@ -0,0 +1,105 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003, 2006-2007, 2009-2019 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003, 2018.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+#define _GL_USE_STDLIB_ALLOC 1
+#include <config.h>
+
+/* Specification.  */
+#include "malloca.h"
+
+#include "verify.h"
+
+/* The speed critical point in this file is freea() applied to an alloca()
+   result: it must be fast, to match the speed of alloca().  The speed of
+   mmalloca() and freea() in the other case are not critical, because they
+   are only invoked for big memory sizes.
+   Here we use a bit in the address as an indicator, an idea by Ondřej Bílka.
+   malloca() can return three types of pointers:
+     - Pointers ≡ 0 mod 2*sa_alignment_max come from stack allocation.
+     - Pointers ≡ sa_alignment_max mod 2*sa_alignment_max come from heap
+       allocation.
+     - NULL comes from a failed heap allocation.  */
+
+/* Type for holding very small pointer differences.  */
+typedef unsigned char small_t;
+/* Verify that it is wide enough.  */
+verify (2 * sa_alignment_max - 1 <= (small_t) -1);
+
+void *
+mmalloca (size_t n)
+{
+#if HAVE_ALLOCA
+  /* Allocate one more word, used to determine the address to pass to freea(),
+     and room for the alignment ≡ sa_alignment_max mod 2*sa_alignment_max.  */
+  size_t nplus = n + sizeof (small_t) + 2 * sa_alignment_max - 1;
+
+  if (nplus >= n)
+    {
+      char *mem = (char *) malloc (nplus);
+
+      if (mem != NULL)
+        {
+          char *p =
+            (char *)((((uintptr_t)mem + sizeof (small_t) + sa_alignment_max - 1)
+                      & ~(uintptr_t)(2 * sa_alignment_max - 1))
+                     + sa_alignment_max);
+          /* Here p >= mem + sizeof (small_t),
+             and p <= mem + sizeof (small_t) + 2 * sa_alignment_max - 1
+             hence p + n <= mem + nplus.
+             So, the memory range [p, p+n) lies in the allocated memory range
+             [mem, mem + nplus).  */
+          ((small_t *) p)[-1] = p - mem;
+          /* p ≡ sa_alignment_max mod 2*sa_alignment_max.  */
+          return p;
+        }
+    }
+  /* Out of memory.  */
+  return NULL;
+#else
+# if !MALLOC_0_IS_NONNULL
+  if (n == 0)
+    n = 1;
+# endif
+  return malloc (n);
+#endif
+}
+
+#if HAVE_ALLOCA
+void
+freea (void *p)
+{
+  /* Check argument.  */
+  if ((uintptr_t) p & (sa_alignment_max - 1))
+    {
+      /* p was not the result of a malloca() call.  Invalid argument.  */
+      abort ();
+    }
+  /* Determine whether p was a non-NULL pointer returned by mmalloca().  */
+  if ((uintptr_t) p & sa_alignment_max)
+    {
+      void *mem = (char *) p - ((small_t *) p)[-1];
+      free (mem);
+    }
+}
+#endif
+
+/*
+ * Hey Emacs!
+ * Local Variables:
+ * coding: utf-8
+ * End:
+ */
diff --git a/lib/malloca.h b/lib/malloca.h
new file mode 100644
index 00000000000..d80c316caa9
--- /dev/null
+++ b/lib/malloca.h
@@ -0,0 +1,127 @@
+/* Safe automatic memory allocation.
+   Copyright (C) 2003-2007, 2009-2019 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+#ifndef _MALLOCA_H
+#define _MALLOCA_H
+
+#include <alloca.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "xalloc-oversized.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* safe_alloca(N) is equivalent to alloca(N) when it is safe to call
+   alloca(N); otherwise it returns NULL.  It either returns N bytes of
+   memory allocated on the stack, that lasts until the function returns,
+   or NULL.
+   Use of safe_alloca should be avoided:
+     - inside arguments of function calls - undefined behaviour,
+     - in inline functions - the allocation may actually last until the
+       calling function returns.
+*/
+#if HAVE_ALLOCA
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.
+   This must be a macro, not a function.  */
+# define safe_alloca(N) ((N) < 4032 ? alloca (N) : NULL)
+#else
+# define safe_alloca(N) ((void) (N), NULL)
+#endif
+
+/* malloca(N) is a safe variant of alloca(N).  It allocates N bytes of
+   memory allocated on the stack, that must be freed using freea() before
+   the function returns.  Upon failure, it returns NULL.  */
+#if HAVE_ALLOCA
+# define malloca(N) \
+  ((N) < 4032 - (2 * sa_alignment_max - 1)                                   \
+   ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
+                + (2 * sa_alignment_max - 1))                                \
+               & ~(uintptr_t)(2 * sa_alignment_max - 1))                     \
+   : mmalloca (N))
+#else
+# define malloca(N) \
+  mmalloca (N)
+#endif
+extern void * mmalloca (size_t n);
+
+/* Free a block of memory allocated through malloca().  */
+#if HAVE_ALLOCA
+extern void freea (void *p);
+#else
+# define freea free
+#endif
+
+/* nmalloca(N,S) is an overflow-safe variant of malloca (N * S).
+   It allocates an array of N objects, each with S bytes of memory,
+   on the stack.  S must be positive and N must be nonnegative.
+   The array must be freed using freea() before the function returns.  */
+#define nmalloca(n, s) (xalloc_oversized (n, s) ? NULL : malloca ((n) * (s)))
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+/* ------------------- Auxiliary, non-public definitions ------------------- */
+
+/* Determine the alignment of a type at compile time.  */
+#if defined __GNUC__ || defined __IBM__ALIGNOF__
+# define sa_alignof __alignof__
+#elif defined __cplusplus
+  template <class type> struct sa_alignof_helper { char __slot1; type __slot2; };
+# define sa_alignof(type) offsetof (sa_alignof_helper<type>, __slot2)
+#elif defined __hpux
+  /* Work around a HP-UX 10.20 cc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#elif defined _AIX
+  /* Work around an AIX 3.2.5 xlc bug with enums constants defined as offsetof
+     values.  */
+# define sa_alignof(type) (sizeof (type) <= 4 ? 4 : 8)
+#else
+# define sa_alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
+#endif
+
+enum
+{
+/* The desired alignment of memory allocations is the maximum alignment
+   among all elementary types.  */
+  sa_alignment_long = sa_alignof (long),
+  sa_alignment_double = sa_alignof (double),
+#if HAVE_LONG_LONG_INT
+  sa_alignment_longlong = sa_alignof (long long),
+#endif
+  sa_alignment_longdouble = sa_alignof (long double),
+  sa_alignment_max = ((sa_alignment_long - 1) | (sa_alignment_double - 1)
+#if HAVE_LONG_LONG_INT
+                      | (sa_alignment_longlong - 1)
+#endif
+                      | (sa_alignment_longdouble - 1)
+                     ) + 1
+};
+
+#endif /* _MALLOCA_H */
diff --git a/lib/pathmax.h b/lib/pathmax.h
new file mode 100644
index 00000000000..9463a1fb2c6
--- /dev/null
+++ b/lib/pathmax.h
@@ -0,0 +1,83 @@
+/* Define PATH_MAX somehow.  Requires sys/types.h.
+   Copyright (C) 1992, 1999, 2001, 2003, 2005, 2009-2019 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+#ifndef _PATHMAX_H
+# define _PATHMAX_H
+
+/* POSIX:2008 defines PATH_MAX to be the maximum number of bytes in a filename,
+   including the terminating NUL byte.
+   <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html>
+   PATH_MAX is not defined on systems which have no limit on filename length,
+   such as GNU/Hurd.
+
+   This file does *not* define PATH_MAX always.  Programs that use this file
+   can handle the GNU/Hurd case in several ways:
+     - Either with a package-wide handling, or with a per-file handling,
+     - Either through a
+         #ifdef PATH_MAX
+       or through a fallback like
+         #ifndef PATH_MAX
+         # define PATH_MAX 8192
+         #endif
+       or through a fallback like
+         #ifndef PATH_MAX
+         # define PATH_MAX pathconf ("/", _PC_PATH_MAX)
+         #endif
+ */
+
+# include <unistd.h>
+
+# include <limits.h>
+
+# ifndef _POSIX_PATH_MAX
+#  define _POSIX_PATH_MAX 256
+# endif
+
+/* Don't include sys/param.h if it already has been.  */
+# if defined HAVE_SYS_PARAM_H && !defined PATH_MAX && !defined MAXPATHLEN
+#  include <sys/param.h>
+# endif
+
+# if !defined PATH_MAX && defined MAXPATHLEN
+#  define PATH_MAX MAXPATHLEN
+# endif
+
+# ifdef __hpux
+/* On HP-UX, PATH_MAX designates the maximum number of bytes in a filename,
+   *not* including the terminating NUL byte, and is set to 1023.
+   Additionally, when _XOPEN_SOURCE is defined to 500 or more, PATH_MAX is
+   not defined at all any more.  */
+#  undef PATH_MAX
+#  define PATH_MAX 1024
+# endif
+
+# if defined _WIN32 && ! defined __CYGWIN__
+/* The page "Naming Files, Paths, and Namespaces" on msdn.microsoft.com,
+   section "Maximum Path Length Limitation",
+   <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file#maximum-path-length-limitation>
+   explains that the maximum size of a filename, including the terminating
+   NUL byte, is 260 = 3 + 256 + 1.
+   This is the same value as
+     - FILENAME_MAX in <stdio.h>,
+     - _MAX_PATH in <stdlib.h>,
+     - MAX_PATH in <windef.h>.
+   Undefine the original value, because mingw's <limits.h> gets it wrong.  */
+#  undef PATH_MAX
+#  define PATH_MAX 260
+# endif
+
+#endif /* _PATHMAX_H */
diff --git a/m4/canonicalize.m4 b/m4/canonicalize.m4
new file mode 100644
index 00000000000..b61747bd1a5
--- /dev/null
+++ b/m4/canonicalize.m4
@@ -0,0 +1,133 @@
+# canonicalize.m4 serial 30
+
+dnl Copyright (C) 2003-2007, 2009-2019 Free Software Foundation, Inc.
+
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Provides canonicalize_file_name and canonicalize_filename_mode, but does
+# not provide or fix realpath.
+AC_DEFUN([gl_FUNC_CANONICALIZE_FILENAME_MODE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+  else
+    case "$gl_cv_func_realpath_works" in
+      *yes) ;;
+      *)    REPLACE_CANONICALIZE_FILE_NAME=1 ;;
+    esac
+  fi
+])
+
+# Provides canonicalize_file_name and realpath.
+AC_DEFUN([gl_CANONICALIZE_LGPL],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_REQUIRE([gl_CANONICALIZE_LGPL_SEPARATE])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+    if test $ac_cv_func_realpath = no; then
+      HAVE_REALPATH=0
+    else
+      case "$gl_cv_func_realpath_works" in
+        *yes) ;;
+        *)    REPLACE_REALPATH=1 ;;
+      esac
+    fi
+  else
+    case "$gl_cv_func_realpath_works" in
+      *yes)
+        ;;
+      *)
+        REPLACE_CANONICALIZE_FILE_NAME=1
+        REPLACE_REALPATH=1
+        ;;
+    esac
+  fi
+])
+
+# Like gl_CANONICALIZE_LGPL, except prepare for separate compilation
+# (no REPLACE_CANONICALIZE_FILE_NAME, no REPLACE_REALPATH, no AC_LIBOBJ).
+AC_DEFUN([gl_CANONICALIZE_LGPL_SEPARATE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name getcwd readlink])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  AC_CHECK_HEADERS_ONCE([sys/param.h])
+])
+
+# Check whether realpath works.  Assume that if a platform has both
+# realpath and canonicalize_file_name, but the former is broken, then
+# so is the latter.
+AC_DEFUN([gl_FUNC_REALPATH_WORKS],
+[
+  AC_CHECK_FUNCS_ONCE([realpath])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether realpath works], [gl_cv_func_realpath_works], [
+    touch conftest.a
+    mkdir conftest.d
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        ]GL_NOCRASH[
+        #include <stdlib.h>
+        #include <string.h>
+      ]], [[
+        int result = 0;
+        {
+          char *name = realpath ("conftest.a", NULL);
+          if (!(name && *name == '/'))
+            result |= 1;
+          free (name);
+        }
+        {
+          char *name = realpath ("conftest.b/../conftest.a", NULL);
+          if (name != NULL)
+            result |= 2;
+          free (name);
+        }
+        {
+          char *name = realpath ("conftest.a/", NULL);
+          if (name != NULL)
+            result |= 4;
+          free (name);
+        }
+        {
+          char *name1 = realpath (".", NULL);
+          char *name2 = realpath ("conftest.d//./..", NULL);
+          if (! name1 || ! name2 || strcmp (name1, name2))
+            result |= 8;
+          free (name1);
+          free (name2);
+        }
+        return result;
+      ]])
+     ],
+     [gl_cv_func_realpath_works=yes],
+     [gl_cv_func_realpath_works=no],
+     [case "$host_os" in
+                       # Guess yes on glibc systems.
+        *-gnu* | gnu*) gl_cv_func_realpath_works="guessing yes" ;;
+                       # Guess yes on musl systems.
+        *-musl*)       gl_cv_func_realpath_works="guessing yes" ;;
+                       # Guess no on native Windows.
+        mingw*)        gl_cv_func_realpath_works="guessing no" ;;
+                       # If we don't know, assume the worst.
+        *)             gl_cv_func_realpath_works="guessing no" ;;
+      esac
+     ])
+    rm -rf conftest.a conftest.d
+  ])
+  case "$gl_cv_func_realpath_works" in
+    *yes)
+      AC_DEFINE([FUNC_REALPATH_WORKS], [1], [Define to 1 if realpath()
+        can malloc memory, always gives an absolute path, and handles
+        trailing slash correctly.])
+      ;;
+  esac
+])
diff --git a/m4/double-slash-root.m4 b/m4/double-slash-root.m4
new file mode 100644
index 00000000000..0c5afb17156
--- /dev/null
+++ b/m4/double-slash-root.m4
@@ -0,0 +1,38 @@
+# double-slash-root.m4 serial 4   -*- Autoconf -*-
+dnl Copyright (C) 2006, 2008-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_DOUBLE_SLASH_ROOT],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CACHE_CHECK([whether // is distinct from /], [gl_cv_double_slash_root],
+    [ if test x"$cross_compiling" = xyes ; then
+        # When cross-compiling, there is no way to tell whether // is special
+        # short of a list of hosts.  However, the only known hosts to date
+        # that have a distinct // are Apollo DomainOS (too old to port to),
+        # Cygwin, and z/OS.  If anyone knows of another system for which // has
+        # special semantics and is distinct from /, please report it to
+        # <bug-gnulib@gnu.org>.
+        case $host in
+          *-cygwin | i370-ibm-openedition)
+            gl_cv_double_slash_root=yes ;;
+          *)
+            # Be optimistic and assume that / and // are the same when we
+            # don't know.
+            gl_cv_double_slash_root='unknown, assuming no' ;;
+        esac
+      else
+        set x `ls -di / // 2>/dev/null`
+        if test "$[2]" = "$[4]" && wc //dev/null >/dev/null 2>&1; then
+          gl_cv_double_slash_root=no
+        else
+          gl_cv_double_slash_root=yes
+        fi
+      fi])
+  if test "$gl_cv_double_slash_root" = yes; then
+    AC_DEFINE([DOUBLE_SLASH_IS_DISTINCT_ROOT], [1],
+      [Define to 1 if // is a file system root distinct from /.])
+  fi
+])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 4627575bf63..cb6dce15ccf 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -52,6 +52,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module byteswap:
   # Code from module c-ctype:
   # Code from module c-strcase:
+  # Code from module canonicalize-lgpl:
   # Code from module careadlinkat:
   # Code from module clock-time:
   # Code from module cloexec:
@@ -113,6 +114,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module limits-h:
   # Code from module localtime-buffer:
   # Code from module lstat:
+  # Code from module malloca:
   # Code from module manywarnings:
   # Code from module memmem-simple:
   # Code from module memrchr:
@@ -125,6 +127,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module nstrftime:
   # Code from module open:
   # Code from module openat-h:
+  # Code from module pathmax:
   # Code from module pipe2:
   # Code from module pselect:
   # Code from module pthread_sigmask:
@@ -199,6 +202,13 @@ AC_DEFUN([gl_INIT],
   gl_FUNC_ALLOCA
   gl___BUILTIN_EXPECT
   gl_BYTESWAP
+  gl_CANONICALIZE_LGPL
+  if test $HAVE_CANONICALIZE_FILE_NAME = 0 || test $REPLACE_CANONICALIZE_FILE_NAME = 1; then
+    AC_LIBOBJ([canonicalize-lgpl])
+  fi
+  gl_MODULE_INDICATOR([canonicalize-lgpl])
+  gl_STDLIB_MODULE_INDICATOR([canonicalize_file_name])
+  gl_STDLIB_MODULE_INDICATOR([realpath])
   AC_CHECK_FUNCS_ONCE([readlinkat])
   gl_CLOCK_TIME
   gl_MODULE_INDICATOR([close-stream])
@@ -447,9 +457,11 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=false
   gl_gnulib_enabled_21ee726a3540c09237a8e70c0baf7467=false
   gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=false
+  gl_gnulib_enabled_malloca=false
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_open=false
   gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
+  gl_gnulib_enabled_pathmax=false
   gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
   gl_gnulib_enabled_strtoll=false
   gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
@@ -561,6 +573,14 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=true
     fi
   }
+  func_gl_gnulib_m4code_malloca ()
+  {
+    if ! $gl_gnulib_enabled_malloca; then
+      gl_MALLOCA
+      gl_gnulib_enabled_malloca=true
+      func_gl_gnulib_m4code_682e609604ccaac6be382e4ee3a4eaec
+    fi
+  }
   func_gl_gnulib_m4code_5264294aa0a5557541b53c8c741f7f31 ()
   {
     if ! $gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31; then
@@ -593,6 +613,13 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=true
     fi
   }
+  func_gl_gnulib_m4code_pathmax ()
+  {
+    if ! $gl_gnulib_enabled_pathmax; then
+      gl_PATHMAX
+      gl_gnulib_enabled_pathmax=true
+    fi
+  }
   func_gl_gnulib_m4code_6099e9737f757db36c47fa9d9f02e88c ()
   {
     if ! $gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c; then
@@ -617,6 +644,12 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=true
     fi
   }
+  if test $HAVE_CANONICALIZE_FILE_NAME = 0 || test $REPLACE_CANONICALIZE_FILE_NAME = 1; then
+    func_gl_gnulib_m4code_malloca
+  fi
+  if test $HAVE_CANONICALIZE_FILE_NAME = 0 || test $REPLACE_CANONICALIZE_FILE_NAME = 1; then
+    func_gl_gnulib_m4code_pathmax
+  fi
   if test $HAVE_FACCESSAT = 0 || test $REPLACE_FACCESSAT = 1; then
     func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b
   fi
@@ -676,9 +709,11 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1], [$gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_21ee726a3540c09237a8e70c0baf7467], [$gl_gnulib_enabled_21ee726a3540c09237a8e70c0baf7467])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9], [$gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_malloca], [$gl_gnulib_enabled_malloca])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_open], [$gl_gnulib_enabled_open])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
+  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_strtoll], [$gl_gnulib_enabled_strtoll])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec], [$gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec])
@@ -845,6 +880,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/c-strcase.h
   lib/c-strcasecmp.c
   lib/c-strncasecmp.c
+  lib/canonicalize-lgpl.c
   lib/careadlinkat.c
   lib/careadlinkat.h
   lib/cdefs.h
@@ -915,6 +951,8 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/localtime-buffer.c
   lib/localtime-buffer.h
   lib/lstat.c
+  lib/malloca.c
+  lib/malloca.h
   lib/md5.c
   lib/md5.h
   lib/memmem.c
@@ -928,6 +966,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/openat-priv.h
   lib/openat-proc.c
   lib/openat.h
+  lib/pathmax.h
   lib/pipe2.c
   lib/pselect.c
   lib/pthread_sigmask.c
@@ -1001,6 +1040,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/alloca.m4
   m4/builtin-expect.m4
   m4/byteswap.m4
+  m4/canonicalize.m4
   m4/clock_time.m4
   m4/copy-file-range.m4
   m4/count-leading-zeros.m4
@@ -1009,6 +1049,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/d-type.m4
   m4/dirent_h.m4
   m4/dirfd.m4
+  m4/double-slash-root.m4
   m4/dup2.m4
   m4/eealloc.m4
   m4/environ.m4
@@ -1048,6 +1089,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/localtime-buffer.m4
   m4/longlong.m4
   m4/lstat.m4
+  m4/malloca.m4
   m4/manywarnings-c++.m4
   m4/manywarnings.m4
   m4/mbstate_t.m4
@@ -1064,6 +1106,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/off_t.m4
   m4/open-cloexec.m4
   m4/open.m4
+  m4/pathmax.m4
   m4/pipe2.m4
   m4/pselect.m4
   m4/pthread_sigmask.m4
diff --git a/m4/malloca.m4 b/m4/malloca.m4
new file mode 100644
index 00000000000..820f40a8a88
--- /dev/null
+++ b/m4/malloca.m4
@@ -0,0 +1,15 @@
+# malloca.m4 serial 1
+dnl Copyright (C) 2003-2004, 2006-2007, 2009-2019 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_MALLOCA],
+[
+  dnl Use the autoconf tests for alloca(), but not the AC_SUBSTed variables
+  dnl @ALLOCA@ and @LTALLOCA@.
+  dnl gl_FUNC_ALLOCA   dnl Already brought in by the module dependencies.
+  AC_REQUIRE([gl_EEMALLOC])
+  AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
+])
diff --git a/m4/pathmax.m4 b/m4/pathmax.m4
new file mode 100644
index 00000000000..0770aca3aac
--- /dev/null
+++ b/m4/pathmax.m4
@@ -0,0 +1,42 @@
+# pathmax.m4 serial 11
+dnl Copyright (C) 2002-2003, 2005-2006, 2009-2019 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_PATHMAX],
+[
+  dnl Prerequisites of lib/pathmax.h.
+  AC_CHECK_HEADERS_ONCE([sys/param.h])
+])
+
+# Expands to a piece of C program that defines PATH_MAX in the same way as
+# "pathmax.h" will do.
+AC_DEFUN([gl_PATHMAX_SNIPPET], [[
+/* Arrange to define PATH_MAX, like "pathmax.h" does. */
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#include <limits.h>
+#if defined HAVE_SYS_PARAM_H && !defined PATH_MAX && !defined MAXPATHLEN
+# include <sys/param.h>
+#endif
+#if !defined PATH_MAX && defined MAXPATHLEN
+# define PATH_MAX MAXPATHLEN
+#endif
+#ifdef __hpux
+# undef PATH_MAX
+# define PATH_MAX 1024
+#endif
+#if defined _WIN32 && ! defined __CYGWIN__
+# undef PATH_MAX
+# define PATH_MAX 260
+#endif
+]])
+
+# Prerequisites of gl_PATHMAX_SNIPPET.
+AC_DEFUN([gl_PATHMAX_SNIPPET_PREREQ],
+[
+  AC_CHECK_HEADERS_ONCE([unistd.h sys/param.h])
+])
diff --git a/src/emacs.c b/src/emacs.c
index fd46540ce22..6463c1be1b7 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -709,9 +709,6 @@ load_pdump (int argc, char **argv)
 {
   const char *const suffix = ".pdmp";
   enum pdumper_load_result result;
-#ifdef WINDOWSNT
-  size_t argv0_len;
-#endif
 
   /* TODO: maybe more thoroughly scrub process environment in order to
      make this use case (loading a pdumper image in an unexeced emacs)
@@ -747,17 +744,23 @@ load_pdump (int argc, char **argv)
     }
 
   /* Look for a dump file in the same directory as the executable; it
-     should have the same basename.  */
+     should have the same basename.  If the directory name is, however,
+     a symbolic link, resolve the symbolic symbolic link first.  */
+
+  char* argv0 = realpath (argv[0], NULL);
+  if (!argv0)
+    fatal ("could not resolve realpath of \"%s\": %s",
+           argv0, strerror (errno));
 
-  dump_file = alloca (strlen (argv[0]) + strlen (suffix) + 1);
+  dump_file = alloca (strlen (argv0) + strlen (suffix) + 1);
 #ifdef DOS_NT
   /* Remove the .exe extension if present.  */
-  argv0_len = strlen (argv[0]);
-  if (argv0_len >= 4 && c_strcasecmp (argv[0] + argv0_len - 4, ".exe") == 0)
-    sprintf (dump_file, "%.*s%s", (int)(argv0_len - 4), argv[0], suffix);
+  size_t argv0_len = strlen (argv0);
+  if (argv0_len >= 4 && c_strcasecmp (argv0 + argv0_len - 4, ".exe") == 0)
+    sprintf (dump_file, "%.*s%s", (int)(argv0_len - 4), argv0, suffix);
   else
 #endif
-  sprintf (dump_file, "%s%s", argv[0], suffix);
+  sprintf (dump_file, "%s%s", argv0, suffix);
 
   result = pdumper_load (dump_file);
   if (result == PDUMPER_LOAD_SUCCESS)
@@ -790,17 +793,17 @@ load_pdump (int argc, char **argv)
 
   if (result == PDUMPER_LOAD_FILE_NOT_FOUND)
     {
-      /* Finally, look for basename(argv[0])+".pdmp" in PATH_EXEC.
+      /* Finally, look for basename(argv0)+".pdmp" in PATH_EXEC.
 	 This way, they can rename both the executable and its pdump
 	 file in PATH_EXEC, and have several Emacs configurations in
 	 the same versioned libexec subdirectory.  */
       char *p, *last_sep = NULL;
-      for (p = argv[0]; *p; p++)
+      for (p = argv0; *p; p++)
 	{
 	  if (IS_DIRECTORY_SEP (*p))
 	    last_sep = p;
 	}
-      argv0_base = last_sep ? last_sep + 1 : argv[0];
+      argv0_base = last_sep ? last_sep + 1 : argv0;
       dump_file = alloca (strlen (path_exec)
 			  + 1
 			  + strlen (argv0_base)