Use putenv+unsetenv instead of modifying environ directly.

* admin/merge-gnulib (GNULIB_MODULES): Add putenv, unsetenv.
* lib/putenv.c, lib/unsetenv.c, m4/putenv.m4, m4/setenv.m4:
New files, copied automatically from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* src/alloc.c (xputenv): New function.
* src/dbusbind.c (Fdbus_init_bus):
* src/emacs.c (main):
* src/xterm.c (x_term_init):
Use xputenv instead of setenv or putenv, to detect memory exhaustion.
* src/editfns.c (initial_tz): Move static var decl up.
(tzvalbuf_in_environ): New static var.
(init_editfns):	Initialize these two static vars.
(Fencode_time): Don't assume arbitrary limit on EMACS_INT width.
Save old TZ value on stack, if it's small.
(Fencode_time, set_time_zone_rule): Don't modify 'environ' directly;
instead, use xputenv+unsetenv to set and restore TZ.
(environbuf): Remove static var.  All uses removed.
(Fset_time_zone_rule): Do not save TZ and environ;
no longer needed here.
(set_time_zone_rule_tz1, set_time_zone_rule_tz2) [LOCALTIME_CACHE]:
Move to inside set_time_zone_rule; they don't need file scope any more.
(set_time_zone_rule): Maintain the TZ=value string separately.
(syms_of_editfns): Don't initialize initial_tz;
init_editfns now does it.
* src/emacs.c (dump_tz) [HAVE_TZSET]: Now const.
* src/lisp.h (xputenv): New decl.

Fixes: debbugs:13070

1 files changed, 1 insertions, 4 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 8acd1d7843e..e9e99574663 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -9908,10 +9908,7 @@ x_term_init (Lisp_Object display_name, char *xrm_option, char *resource_name)
 
         /* Emacs can only handle core input events, so make sure
            Gtk doesn't use Xinput or Xinput2 extensions.  */
-        {
-          static char fix_events[] = "GDK_CORE_DEVICE_EVENTS=1";
-          putenv (fix_events);
-        }
+        xputenv ("GDK_CORE_DEVICE_EVENTS=1");
 
         /* Work around GLib bug that outputs a faulty warning. See
            https://bugzilla.gnome.org/show_bug.cgi?id=563627.  */