Remove Gnulib putenv code

It’s not needed, since Emacs always uses the system putenv and all
platforms have putenv.  This improves on the fix for Bug#19874.
Suggested by Bruno Haible.
* admin/merge-gnulib (GNULIB_MODULES): Remove putenv.
* configure.ac: Remove workarounds for Gnulib putenv module.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/putenv.c, m4/putenv.m4: Remove.

2 files changed, 0 insertions, 206 deletions

diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index ed80f88a874..1c8085b1a41 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -127,7 +127,6 @@
 #  pipe2 \
 #  pselect \
 #  pthread_sigmask \
-#  putenv \
 #  qcopy-acl \
 #  readlink \
 #  readlinkat \
@@ -2162,17 +2161,6 @@ EXTRA_libgnu_a_SOURCES += pthread_sigmask.c
 endif
 ## end   gnulib module pthread_sigmask
 
-## begin gnulib module putenv
-ifeq (,$(OMIT_GNULIB_MODULE_putenv))
-
-
-EXTRA_DIST += putenv.c
-
-EXTRA_libgnu_a_SOURCES += putenv.c
-
-endif
-## end   gnulib module putenv
-
 ## begin gnulib module qcopy-acl
 ifeq (,$(OMIT_GNULIB_MODULE_qcopy-acl))
 
diff --git a/lib/putenv.c b/lib/putenv.c
deleted file mode 100644
index 9e862e63d3d..00000000000
--- a/lib/putenv.c
+++ /dev/null
@@ -1,194 +0,0 @@
-/* Copyright (C) 1991, 1994, 1997-1998, 2000, 2003-2020 Free Software
-   Foundation, Inc.
-
-   NOTE: The canonical source of this file is maintained with the GNU C
-   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
-
-   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 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/>.  */
-
-#include <config.h>
-
-/* Specification.  */
-#include <stdlib.h>
-
-#include <stddef.h>
-
-/* Include errno.h *after* sys/types.h to work around header problems
-   on AIX 3.2.5.  */
-#include <errno.h>
-#ifndef __set_errno
-# define __set_errno(ev) ((errno) = (ev))
-#endif
-
-#include <string.h>
-#include <unistd.h>
-
-#if defined _WIN32 && ! defined __CYGWIN__
-# define WIN32_LEAN_AND_MEAN
-# include <windows.h>
-#endif
-
-#if _LIBC
-# if HAVE_GNU_LD
-#  define environ __environ
-# else
-extern char **environ;
-# endif
-#endif
-
-#if _LIBC
-/* This lock protects against simultaneous modifications of 'environ'.  */
-# include <bits/libc-lock.h>
-__libc_lock_define_initialized (static, envlock)
-# define LOCK   __libc_lock_lock (envlock)
-# define UNLOCK __libc_lock_unlock (envlock)
-#else
-# define LOCK
-# define UNLOCK
-#endif
-
-static int
-_unsetenv (const char *name)
-{
-  size_t len;
-#if !HAVE_DECL__PUTENV
-  char **ep;
-#endif
-
-  if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
-    {
-      __set_errno (EINVAL);
-      return -1;
-    }
-
-  len = strlen (name);
-
-#if HAVE_DECL__PUTENV
-  {
-    int putenv_result, putenv_errno;
-    char *name_ = malloc (len + 2);
-    memcpy (name_, name, len);
-    name_[len] = '=';
-    name_[len + 1] = 0;
-    putenv_result = _putenv (name_);
-    putenv_errno = errno;
-    free (name_);
-    __set_errno (putenv_errno);
-    return putenv_result;
-  }
-#else
-
-  LOCK;
-
-  ep = environ;
-  while (*ep != NULL)
-    if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
-      {
-        /* Found it.  Remove this pointer by moving later ones back.  */
-        char **dp = ep;
-
-        do
-          dp[0] = dp[1];
-        while (*dp++);
-        /* Continue the loop in case NAME appears again.  */
-      }
-    else
-      ++ep;
-
-  UNLOCK;
-
-  return 0;
-#endif
-}
-
-
-/* Put STRING, which is of the form "NAME=VALUE", in the environment.
-   If STRING contains no '=', then remove STRING from the environment.  */
-int
-putenv (char *string)
-{
-  const char *name_end = strchr (string, '=');
-  char **ep;
-
-  if (name_end == NULL)
-    {
-      /* Remove the variable from the environment.  */
-      return _unsetenv (string);
-    }
-
-#if HAVE_DECL__PUTENV
-  /* Rely on _putenv to allocate the new environment.  If other
-     parts of the application use _putenv, the !HAVE_DECL__PUTENV code
-     would fight over who owns the environ vector, causing a crash.  */
-  if (name_end[1])
-    return _putenv (string);
-  else
-    {
-      /* _putenv ("NAME=") unsets NAME, so invoke _putenv ("NAME= ")
-         to allocate the environ vector and then replace the new
-         entry with "NAME=".  */
-      int putenv_result, putenv_errno;
-      char *name_x = malloc (name_end - string + sizeof "= ");
-      if (!name_x)
-        return -1;
-      memcpy (name_x, string, name_end - string + 1);
-      name_x[name_end - string + 1] = ' ';
-      name_x[name_end - string + 2] = 0;
-      putenv_result = _putenv (name_x);
-      putenv_errno = errno;
-      for (ep = environ; *ep; ep++)
-        if (strcmp (*ep, name_x) == 0)
-          {
-            *ep = string;
-            break;
-          }
-# if defined _WIN32 && ! defined __CYGWIN__
-      if (putenv_result == 0)
-        {
-          /* _putenv propagated "NAME= " into the subprocess environment;
-             fix that by calling SetEnvironmentVariable directly.  */
-          name_x[name_end - string] = 0;
-          putenv_result = SetEnvironmentVariable (name_x, "") ? 0 : -1;
-          putenv_errno = ENOMEM; /* ENOMEM is the only way to fail.  */
-        }
-# endif
-      free (name_x);
-      __set_errno (putenv_errno);
-      return putenv_result;
-    }
-#else
-  for (ep = environ; *ep; ep++)
-    if (strncmp (*ep, string, name_end - string) == 0
-        && (*ep)[name_end - string] == '=')
-      break;
-
-  if (*ep)
-    *ep = string;
-  else
-    {
-      static char **last_environ = NULL;
-      size_t size = ep - environ;
-      char **new_environ = malloc ((size + 2) * sizeof *new_environ);
-      if (! new_environ)
-        return -1;
-      new_environ[0] = string;
-      memcpy (new_environ + 1, environ, (size + 1) * sizeof *new_environ);
-      free (last_environ);
-      last_environ = new_environ;
-      environ = new_environ;
-    }
-
-  return 0;
-#endif
-}