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, 26 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 54985d33b59..0be3eee6726 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,29 @@
+2012-12-08  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use putenv+unsetenv instead of modifying environ directly (Bug#13070).
+        * alloc.c (xputenv): New function.
+        * dbusbind.c (Fdbus_init_bus):
+        * emacs.c (main):
+        * xterm.c (x_term_init):
+        Use xputenv instead of setenv or putenv, to detect memory exhaustion.
+        * 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.
+        * emacs.c (dump_tz) [HAVE_TZSET]: Now const.
+        * lisp.h (xputenv): New decl.
+
 2012-12-08  Fabrice Popineau  <fabrice.popineau@gmail.com>
 
         * w32fns.c (emacs_abort): Don't do arithmetics on void pointers.