Merge from Gnulib

This incorporates:
2017-11-23 stat: work around Solaris bug with tv_nsec < 0
2017-11-12 maint: shorten https://lists.gnu.org/archive/html/... links
* build-aux/config.sub, doc/misc/texinfo.tex, lib/allocator.h:
* lib/fstatat.c, lib/intprops.h, lib/lstat.c, lib/signal.in.h:
* lib/stat-time.h, lib/stdio-impl.h, lib/stdio.in.h:
* lib/timespec.h, m4/alloca.m4, m4/extern-inline.m4:
* m4/faccessat.m4, m4/fstatat.m4, m4/gnulib-common.m4:
* m4/lstat.m4, m4/std-gnu11.m4, m4/sys_types_h.m4:
* m4/vararrays.m4:
Copy from Gnulib.

20 files changed, 162 insertions, 76 deletions

diff --git a/build-aux/config.sub b/build-aux/config.sub
index fb579478695..00f68b8e5f3 100755
--- a/build-aux/config.sub
+++ b/build-aux/config.sub
@@ -2,7 +2,7 @@
 # Configuration validation subroutine script.
 #   Copyright 1992-2017 Free Software Foundation, Inc.
 
-timestamp='2017-11-04'
+timestamp='2017-11-23'
 
 # 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
@@ -1546,6 +1546,19 @@ case $os in
         -dicos*)
                 os=-dicos
                 ;;
+        -pikeos*)
+                # Until real need of OS specific support for
+                # particular features comes up, bare metal
+                # configurations are quite functional.
+                case $basic_machine in
+                    arm*)
+                        os=-eabi
+                        ;;
+                    *)
+                        os=-elf
+                        ;;
+                esac
+                ;;
         -nacl*)
                 ;;
         -ios)
diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index 022c3f5b370..e2bf51af8c0 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2017-09-11.18}
+\def\texinfoversion{2017-11-17.06}
 %
 % Copyright 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,
 % 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
@@ -5969,24 +5969,30 @@ end
     % Split the last of the double-column material.
     \savemarks
     \balancecolumns
-    %
+  }%
+  \eject % call the \output just set
+  \ifdim\pagetotal=0pt
     % Having called \balancecolumns once, we do not
     % want to call it again.  Therefore, reset \output to its normal
     % definition right away.
     \global\output = {\onepageout{\pagecontents\PAGE}}%
-  }%
-  \eject
-  \endgroup % started in \begindoublecolumns
-  \restoremarks
-  % Leave the double-column material on the current page, no automatic
-  % page break.
-  \box\balancedcolumns
-  %
-  % \pagegoal was set to the doubled \vsize above, since we restarted
-  % the current page.  We're now back to normal single-column
-  % typesetting, so reset \pagegoal to the normal \vsize.
-  \global\vsize = \txipageheight %
-  \pagegoal = \txipageheight %
+    %
+    \endgroup % started in \begindoublecolumns
+    \restoremarks
+    % Leave the double-column material on the current page, no automatic
+    % page break.
+    \box\balancedcolumns
+    %
+    % \pagegoal was set to the doubled \vsize above, since we restarted
+    % the current page.  We're now back to normal single-column
+    % typesetting, so reset \pagegoal to the normal \vsize.
+    \global\vsize = \txipageheight %
+    \pagegoal = \txipageheight %
+  \else
+    % We had some left-over material.  This might happen when \doublecolumnout
+    % is called in \balancecolumns.  Try again.
+    \expandafter\enddoublecolumns
+  \fi
 }
 \newbox\balancedcolumns
 \setbox\balancedcolumns=\vbox{shouldnt see this}%
@@ -6001,6 +6007,7 @@ end
   \ifdim\dimen@<5\baselineskip
     % Don't split a short final column in two.
     \setbox2=\vbox{}%
+    \global\setbox\balancedcolumns=\vbox{\pagesofar}%
   \else
     \divide\dimen@ by 2 % target to split to
     \dimen@ii = \dimen@
@@ -6016,15 +6023,15 @@ end
       \repeat
     }%
     % Now the left column is in box 1, and the right column in box 3.
+    %
     % Check whether the left column has come out higher than the page itself.  
     % (Note that we have doubled \vsize for the double columns, so
     % the actual height of the page is 0.5\vsize).
     \ifdim2\ht1>\vsize
-      % Just split the last of the double column material roughly in half.
-      \setbox2=\box0
-      \setbox0 = \vsplit2 to \dimen@ii
-      \setbox0=\vbox to \dimen@ii {\unvbox0\vfill}%
-      \setbox2=\vbox to \dimen@ii {\unvbox2\vfill}%
+      % It appears that we have been called upon to balance too much material.
+      % Output some of it with \doublecolumnout, leaving the rest on the page.
+      \setbox\PAGE=\box0
+      \doublecolumnout
     \else
       % Compare the heights of the two columns.
       \ifdim4\ht1>5\ht3
@@ -6037,10 +6044,10 @@ end
         \setbox2=\vbox to\ht1{\unvbox3\unskip}%
         \setbox0=\vbox to\ht1{\unvbox1\unskip}%
       \fi
+      \global\setbox\balancedcolumns=\vbox{\pagesofar}%
     \fi
   \fi
   %
-  \global\setbox\balancedcolumns=\vbox{\pagesofar}%
 }
 \catcode`\@ = \other
 
diff --git a/lib/allocator.h b/lib/allocator.h
index 8f79d7435c3..fc3d646aa54 100644
--- a/lib/allocator.h
+++ b/lib/allocator.h
@@ -29,7 +29,7 @@ struct allocator
   /* Do not use GCC attributes such as __attribute__ ((malloc)) with
      the function types pointed at by these members, because these
      attributes do not work with pointers to functions.  See
-     <https://lists.gnu.org/archive/html/bug-gnulib/2011-04/msg00007.html>.  */
+     <https://lists.gnu.org/r/bug-gnulib/2011-04/msg00007.html>.  */
 
   /* Call ALLOCATE to allocate memory, like 'malloc'.  On failure ALLOCATE
      should return NULL, though not necessarily set errno.  When given
diff --git a/lib/fstatat.c b/lib/fstatat.c
index 294861f51b1..237e68c5da7 100644
--- a/lib/fstatat.c
+++ b/lib/fstatat.c
@@ -41,6 +41,8 @@ orig_fstatat (int fd, char const *filename, struct stat *buf, int flags)
    above.  */
 #include "sys/stat.h"
 
+#include "stat-time.h"
+
 #include <errno.h>
 #include <fcntl.h>
 #include <string.h>
@@ -51,6 +53,12 @@ orig_fstatat (int fd, char const *filename, struct stat *buf, int flags)
 #  define LSTAT_FOLLOWS_SLASHED_SYMLINK 0
 # endif
 
+static int
+normal_fstatat (int fd, char const *file, struct stat *st, int flag)
+{
+  return stat_time_normalize (orig_fstatat (fd, file, st, flag), st);
+}
+
 /* fstatat should always follow symbolic links that end in /, but on
    Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified.
    Likewise, trailing slash on a non-directory should be an error.
@@ -63,7 +71,7 @@ orig_fstatat (int fd, char const *filename, struct stat *buf, int flags)
 int
 rpl_fstatat (int fd, char const *file, struct stat *st, int flag)
 {
-  int result = orig_fstatat (fd, file, st, flag);
+  int result = normal_fstatat (fd, file, st, flag);
   size_t len;
 
   if (LSTAT_FOLLOWS_SLASHED_SYMLINK || result != 0)
@@ -79,7 +87,7 @@ rpl_fstatat (int fd, char const *file, struct stat *st, int flag)
           errno = ENOTDIR;
           return -1;
         }
-      result = orig_fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW);
+      result = normal_fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW);
     }
   /* Fix stat behavior.  */
   if (result == 0 && !S_ISDIR (st->st_mode) && file[len - 1] == '/')
diff --git a/lib/intprops.h b/lib/intprops.h
index a34e81c7b5e..2df7b1f9f69 100644
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -26,7 +26,7 @@
 #define _GL_INT_CONVERT(e, v) (0 * (e) + (v))
 
 /* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see
-   <https://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00406.html>.  */
+   <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00406.html>.  */
 #define _GL_INT_NEGATE_CONVERT(e, v) (0 * (e) - (v))
 
 /* The extra casts in the following macros work around compiler bugs,
@@ -179,7 +179,7 @@
 /* Return 1 if A * B would overflow in [MIN,MAX] arithmetic.
    See above for restrictions.  Avoid && and || as they tickle
    bugs in Sun C 5.11 2010/08/13 and other compilers; see
-   <https://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00401.html>.  */
+   <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00401.html>.  */
 #define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max)     \
   ((b) < 0                                              \
    ? ((a) < 0                                           \
@@ -443,7 +443,7 @@
    implementation-defined result or signal for values outside T's
    range.  However, code that works around this theoretical problem
    runs afoul of a compiler bug in Oracle Studio 12.3 x86.  See:
-   https://lists.gnu.org/archive/html/bug-gnulib/2017-04/msg00049.html
+   https://lists.gnu.org/r/bug-gnulib/2017-04/msg00049.html
    As the compiler bug is real, don't try to work around the
    theoretical problem.  */
 
diff --git a/lib/lstat.c b/lib/lstat.c
index c721a4e641c..f3c61779540 100644
--- a/lib/lstat.c
+++ b/lib/lstat.c
@@ -47,6 +47,8 @@ orig_lstat (const char *filename, struct stat *buf)
    above.  */
 # include "sys/stat.h"
 
+# include "stat-time.h"
+
 # include <string.h>
 # include <errno.h>
 
@@ -66,32 +68,33 @@ orig_lstat (const char *filename, struct stat *buf)
 int
 rpl_lstat (const char *file, struct stat *sbuf)
 {
-  size_t len;
-  int lstat_result = orig_lstat (file, sbuf);
-
-  if (lstat_result != 0)
-    return lstat_result;
+  int result = orig_lstat (file, sbuf);
 
   /* This replacement file can blindly check against '/' rather than
      using the ISSLASH macro, because all platforms with '\\' either
      lack symlinks (mingw) or have working lstat (cygwin) and thus do
      not compile this file.  0 len should have already been filtered
      out above, with a failure return of ENOENT.  */
-  len = strlen (file);
-  if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode))
-    return 0;
-
-  /* At this point, a trailing slash is only permitted on
-     symlink-to-dir; but it should have found information on the
-     directory, not the symlink.  Call stat() to get info about the
-     link's referent.  Our replacement stat guarantees valid results,
-     even if the symlink is not pointing to a directory.  */
-  if (!S_ISLNK (sbuf->st_mode))
+  if (result == 0)
     {
-      errno = ENOTDIR;
-      return -1;
+      if (S_ISDIR (sbuf->st_mode) || file[strlen (file) - 1] != '/')
+        result = stat_time_normalize (result, sbuf);
+      else
+        {
+          /* At this point, a trailing slash is permitted only on
+             symlink-to-dir; but it should have found information on the
+             directory, not the symlink.  Call 'stat' to get info about the
+             link's referent.  Our replacement stat guarantees valid results,
+             even if the symlink is not pointing to a directory.  */
+          if (!S_ISLNK (sbuf->st_mode))
+            {
+              errno = ENOTDIR;
+              return -1;
+            }
+          result = stat (file, sbuf);
+        }
     }
-  return stat (file, sbuf);
+  return result;
 }
 
 #endif /* HAVE_LSTAT */
diff --git a/lib/signal.in.h b/lib/signal.in.h
index 9c32b14962f..e8107c37bf5 100644
--- a/lib/signal.in.h
+++ b/lib/signal.in.h
@@ -200,7 +200,7 @@ typedef int verify_NSIG_constraint[NSIG <= 32 ? 1 : -1];
 /* When also using extern inline, suppress the use of static inline in
    standard headers of problematic Apple configurations, as Libc at
    least through Libc-825.26 (2013-04-09) mishandles it; see, e.g.,
-   <https://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
+   <https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html>.
    Perhaps Apple will fix this some day.  */
 #if (defined _GL_EXTERN_INLINE_IN_USE && defined __APPLE__ \
      && (defined __i386__ || defined __x86_64__))
diff --git a/lib/stat-time.h b/lib/stat-time.h
index 47a3bf8f21e..1cf821992ed 100644
--- a/lib/stat-time.h
+++ b/lib/stat-time.h
@@ -20,6 +20,10 @@
 #ifndef STAT_TIME_H
 #define STAT_TIME_H 1
 
+#include "intprops.h"
+
+#include <errno.h>
+#include <stddef.h>
 #include <sys/stat.h>
 #include <time.h>
 
@@ -202,6 +206,47 @@ get_stat_birthtime (struct stat const *st)
   return t;
 }
 
+/* If a stat-like function returned RESULT, normalize the timestamps
+   in *ST, in case this platform suffers from the Solaris 11 bug where
+   tv_nsec might be negative.  Return the adjusted RESULT, setting
+   errno to EOVERFLOW if normalization overflowed.  This function
+   is intended to be private to this .h file.  */
+_GL_STAT_TIME_INLINE int
+stat_time_normalize (int result, struct stat *st)
+{
+#if defined __sun && defined STAT_TIMESPEC
+  if (result == 0)
+    {
+      long int timespec_resolution = 1000000000;
+      short int const ts_off[] = { offsetof (struct stat, st_atim),
+                                   offsetof (struct stat, st_mtim),
+                                   offsetof (struct stat, st_ctim) };
+      int i;
+      for (i = 0; i < sizeof ts_off / sizeof *ts_off; i++)
+        {
+          struct timespec *ts = (struct timespec *) ((char *) st + ts_off[i]);
+          long int q = ts->tv_nsec / timespec_resolution;
+          long int r = ts->tv_nsec % timespec_resolution;
+          if (r < 0)
+            {
+              r += timespec_resolution;
+              q--;
+            }
+          ts->tv_nsec = r;
+          /* Overflow is possible, as Solaris 11 stat can yield
+             tv_sec == TYPE_MINIMUM (time_t) && tv_nsec == -1000000000.
+             INT_ADD_WRAPV is OK, since time_t is signed on Solaris.  */
+          if (INT_ADD_WRAPV (q, ts->tv_sec, &ts->tv_sec))
+            {
+              errno = EOVERFLOW;
+              return -1;
+            }
+        }
+    }
+#endif
+  return result;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/stdio-impl.h b/lib/stdio-impl.h
index 8960333687e..329801ad23b 100644
--- a/lib/stdio-impl.h
+++ b/lib/stdio-impl.h
@@ -81,7 +81,7 @@
 #ifdef __TANDEM                     /* NonStop Kernel */
 # ifndef _IOERR
 /* These values were determined by the program 'stdioext-flags' at
-   <https://lists.gnu.org/archive/html/bug-gnulib/2010-12/msg00165.html>.  */
+   <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 #  define _IOERR   0x40
 #  define _IOREAD  0x80
 #  define _IOWRT    0x4
@@ -132,7 +132,7 @@ struct _gl_real_FILE
 # define fp_ ((struct _gl_real_FILE *) fp)
 
 /* These values were determined by a program similar to the one at
-   <https://lists.gnu.org/archive/html/bug-gnulib/2010-12/msg00165.html>.  */
+   <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 # define _IOREAD   0x1
 # define _IOWRT    0x2
 # define _IORW     0x4
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index 066e08eba9a..505f3f49f4e 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -152,7 +152,7 @@
 /* When also using extern inline, suppress the use of static inline in
    standard headers of problematic Apple configurations, as Libc at
    least through Libc-825.26 (2013-04-09) mishandles it; see, e.g.,
-   <https://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
+   <https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html>.
    Perhaps Apple will fix this some day.  */
 #if (defined _GL_EXTERN_INLINE_IN_USE && defined __APPLE__ \
      && defined __GNUC__ && defined __STDC__)
diff --git a/lib/timespec.h b/lib/timespec.h
index cc34067374f..84c8146a3ea 100644
--- a/lib/timespec.h
+++ b/lib/timespec.h
@@ -87,7 +87,7 @@ timespec_cmp (struct timespec a, struct timespec b)
     return 1;
 
   /* Pacify gcc -Wstrict-overflow (bleeding-edge circa 2017-10-02).  See:
-     http://lists.gnu.org/archive/html/bug-gnulib/2017-10/msg00006.html  */
+     http://lists.gnu.org/r/bug-gnulib/2017-10/msg00006.html  */
   assume (-1 <= a.tv_nsec && a.tv_nsec <= 2 * TIMESPEC_RESOLUTION);
   assume (-1 <= b.tv_nsec && b.tv_nsec <= 2 * TIMESPEC_RESOLUTION);
 
diff --git a/m4/alloca.m4 b/m4/alloca.m4
index d1224316498..867954a2e37 100644
--- a/m4/alloca.m4
+++ b/m4/alloca.m4
@@ -44,7 +44,7 @@ AC_DEFUN([gl_FUNC_ALLOCA],
 AC_DEFUN([gl_PREREQ_ALLOCA], [:])
 
 # This works around a bug in autoconf <= 2.68.
-# See <https://lists.gnu.org/archive/html/bug-gnulib/2011-06/msg00277.html>.
+# See <https://lists.gnu.org/r/bug-gnulib/2011-06/msg00277.html>.
 
 m4_version_prereq([2.69], [] ,[
 
diff --git a/m4/extern-inline.m4 b/m4/extern-inline.m4
index c08af18af68..207aa6a0895 100644
--- a/m4/extern-inline.m4
+++ b/m4/extern-inline.m4
@@ -11,7 +11,7 @@ AC_DEFUN([gl_EXTERN_INLINE],
 [/* Please see the Gnulib manual for how to use these macros.
 
    Suppress extern inline with HP-UX cc, as it appears to be broken; see
-   <https://lists.gnu.org/archive/html/bug-texinfo/2013-02/msg00030.html>.
+   <https://lists.gnu.org/r/bug-texinfo/2013-02/msg00030.html>.
 
    Suppress extern inline with Sun C in standards-conformance mode, as it
    mishandles inline functions that call each other.  E.g., for 'inline void f
@@ -28,13 +28,13 @@ AC_DEFUN([gl_EXTERN_INLINE],
    from calling static functions.  This bug is known to occur on:
 
      OS X 10.8 and earlier; see:
-     https://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html
+     https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
 
      DragonFly; see
      http://muscles.dragonflybsd.org/bulk/bleeding-edge-potential/latest-per-pkg/ah-tty-0.3.12.log
 
      FreeBSD; see:
-     https://lists.gnu.org/archive/html/bug-gnulib/2014-07/msg00104.html
+     https://lists.gnu.org/r/bug-gnulib/2014-07/msg00104.html
 
    OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
    for clang but remains for g++; see <https://trac.macports.org/ticket/41033>.
diff --git a/m4/faccessat.m4 b/m4/faccessat.m4
index f4cb49d166c..c64545abd46 100644
--- a/m4/faccessat.m4
+++ b/m4/faccessat.m4
@@ -1,4 +1,4 @@
-# serial 7
+# serial 8
 # See if we need to provide faccessat replacement.
 
 dnl Copyright (C) 2009-2017 Free Software Foundation, Inc.
@@ -11,6 +11,7 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_FACCESSAT],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
 
   dnl Persuade glibc <unistd.h> to declare faccessat().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
@@ -18,8 +19,11 @@ AC_DEFUN([gl_FUNC_FACCESSAT],
   AC_CHECK_FUNCS_ONCE([faccessat])
   if test $ac_cv_func_faccessat = no; then
     HAVE_FACCESSAT=0
-  elif test "$gl_cv_func_lstat_dereferences_slashed_symlink" != yes; then
-    REPLACE_FACCESSAT=1
+  else
+    case "$gl_cv_func_lstat_dereferences_slashed_symlink" in
+      *yes) ;;
+      *)    REPLACE_FACCESSAT=1 ;;
+    esac
   fi
 ])
 
diff --git a/m4/fstatat.m4 b/m4/fstatat.m4
index b29ec9258e9..767eb83db4b 100644
--- a/m4/fstatat.m4
+++ b/m4/fstatat.m4
@@ -1,4 +1,4 @@
-# fstatat.m4 serial 3
+# fstatat.m4 serial 4
 dnl Copyright (C) 2004-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -13,14 +13,14 @@ AC_DEFUN([gl_FUNC_FSTATAT],
   AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([AC_CANONICAL_HOST])
   AC_CHECK_FUNCS_ONCE([fstatat])
 
   if test $ac_cv_func_fstatat = no; then
     HAVE_FSTATAT=0
   else
     dnl Test for an AIX 7.1 bug; see
-    dnl <https://lists.gnu.org/archive/html/bug-tar/2011-09/msg00015.html>.
+    dnl <https://lists.gnu.org/r/bug-tar/2011-09/msg00015.html>.
     AC_CACHE_CHECK([whether fstatat (..., 0) works],
       [gl_cv_func_fstatat_zero_flag],
       [AC_RUN_IFELSE(
@@ -46,15 +46,20 @@ AC_DEFUN([gl_FUNC_FSTATAT],
 
     case $gl_cv_func_fstatat_zero_flag+$gl_cv_func_lstat_dereferences_slashed_symlink in
     *yes+*yes) ;;
-    *) REPLACE_FSTATAT=1
-       case $gl_cv_func_fstatat_zero_flag in
-       *yes)
+    *) REPLACE_FSTATAT=1 ;;
+    esac
+
+    case $host_os in
+      solaris*)
+        REPLACE_FSTATAT=1 ;;
+    esac
+
+    case $REPLACE_FSTATAT,$gl_cv_func_fstatat_zero_flag in
+      1,*yes)
          AC_DEFINE([HAVE_WORKING_FSTATAT_ZERO_FLAG], [1],
            [Define to 1 if fstatat (..., 0) works.
             For example, it does not work in AIX 7.1.])
          ;;
-       esac
-       ;;
     esac
   fi
 ])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 36da841287d..bea5a650e76 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -228,13 +228,13 @@ m4_ifndef([AS_VAR_IF],
 # This is like AC_PROG_CC_C99, except that
 # - AC_PROG_CC_C99 did not exist in Autoconf versions < 2.60,
 # - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
-#   <https://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00367.html>,
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00367.html>,
 #   but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
-#   <https://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00441.html>.
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00441.html>.
 # Remaining problems:
 # - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options
 #   to CC twice
-#   <https://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00431.html>.
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00431.html>.
 # - AC_PROG_CC_STDC is likely to change now that C11 is an ISO standard.
 AC_DEFUN([gl_PROG_CC_C99],
 [
diff --git a/m4/lstat.m4 b/m4/lstat.m4
index 0b6e5d70cba..6ba18cec574 100644
--- a/m4/lstat.m4
+++ b/m4/lstat.m4
@@ -1,4 +1,4 @@
-# serial 29
+# serial 30
 
 # Copyright (C) 1997-2001, 2003-2017 Free Software Foundation, Inc.
 #
@@ -10,14 +10,15 @@ dnl From Jim Meyering.
 
 AC_DEFUN([gl_FUNC_LSTAT],
 [
+  AC_REQUIRE([AC_CANONICAL_HOST])
   AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
   dnl If lstat does not exist, the replacement <sys/stat.h> does
   dnl "#define lstat stat", and lstat.c is a no-op.
   AC_CHECK_FUNCS_ONCE([lstat])
   if test $ac_cv_func_lstat = yes; then
     AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
-    case "$gl_cv_func_lstat_dereferences_slashed_symlink" in
-      *no)
+    case $host_os,$gl_cv_func_lstat_dereferences_slashed_symlink in
+      solaris* | *no)
         REPLACE_LSTAT=1
         ;;
     esac
diff --git a/m4/std-gnu11.m4 b/m4/std-gnu11.m4
index 3c2f26f4666..c0466beb404 100644
--- a/m4/std-gnu11.m4
+++ b/m4/std-gnu11.m4
@@ -369,7 +369,7 @@ dnl		just the module.  Instead, define the (private) symbol
 dnl             _STDC_C99, which suppresses a bogus failure in <stdbool.h>.
 dnl             The resulting compiler passes the test case here, and that's
 dnl             good enough.  For more, please see the thread starting at:
-dnl            https://lists.gnu.org/archive/html/autoconf/2010-12/msg00059.html
+dnl            https://lists.gnu.org/r/autoconf/2010-12/msg00059.html
 dnl Tru64       -c99
 dnl with extended modes being tried first.
 [[-std=gnu99 -std=c99 -c99 -AC99 -D_STDC_C99= -qlanglvl=extc1x -qlanglvl=extc99]], [$1], [$2])[]dnl
@@ -458,7 +458,7 @@ dnl preferably extc11.
 # --------------
 # Do not use AU_ALIAS here and in AC_PROG_CC_C99 and AC_PROG_CC_STDC,
 # as that'd be incompatible with how Automake redefines AC_PROG_CC.  See
-# <https://lists.gnu.org/archive/html/autoconf/2012-10/msg00048.html>.
+# <https://lists.gnu.org/r/autoconf/2012-10/msg00048.html>.
 AU_DEFUN([AC_PROG_CC_C89],
   [AC_REQUIRE([AC_PROG_CC])],
   [$0 is obsolete; use AC_PROG_CC]
diff --git a/m4/sys_types_h.m4 b/m4/sys_types_h.m4
index de56d04fc15..75097713d98 100644
--- a/m4/sys_types_h.m4
+++ b/m4/sys_types_h.m4
@@ -35,7 +35,7 @@ AC_DEFUN([gl_SYS_TYPES_H_DEFAULTS],
 ])
 
 # This works around a buggy version in autoconf <= 2.69.
-# See <https://lists.gnu.org/archive/html/autoconf/2016-08/msg00014.html>
+# See <https://lists.gnu.org/r/autoconf/2016-08/msg00014.html>
 
 m4_version_prereq([2.70], [], [
 
diff --git a/m4/vararrays.m4 b/m4/vararrays.m4
index 38a3ed23542..2f678e381eb 100644
--- a/m4/vararrays.m4
+++ b/m4/vararrays.m4
@@ -27,7 +27,7 @@ AC_DEFUN([AC_C_VARARRAYS],
              [[/* Test for VLA support.  This test is partly inspired
                   from examples in the C standard.  Use at least two VLA
                   functions to detect the GCC 3.4.3 bug described in:
-                  https://lists.gnu.org/archive/html/bug-gnulib/2014-08/msg00014.html
+                  https://lists.gnu.org/r/bug-gnulib/2014-08/msg00014.html
                   */
                #ifdef __STDC_NO_VLA__
                 syntax error;