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, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 1d4fc853693..f31a03833c1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-12-08  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Use putenv+unsetenv instead of modifying environ directly (Bug#13070).
+        * 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.
+
 2012-12-08  Eli Zaretskii  <eliz@gnu.org>
 
         * lib/makefile.w32-in ($(BLD)/sig2str.$(O)): New dependency.