2 files changed, 8 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 483930a6489..e5d663b746e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2012-12-31  Eli Zaretskii  <eliz@gnu.org>
+
+        * w32.c (unsetenv): Set up the string passed to _putenv
+        correctly.  See
+        http://lists.gnu.org/archive/html/emacs-devel/2012-12/msg00863.html
+        for the bug this caused.
+
 2012-12-30  Paul Eggert  <eggert@cs.ucla.edu>
 
         * coding.c (Qmac): Now static.
diff --git a/src/w32.c b/src/w32.c
index c9adece652b..5e2080139e1 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1784,6 +1784,7 @@ unsetenv (const char *name)
   /* It is safe to use 'alloca' with 32K size, since the stack is at
      least 2MB, and we set it to 8MB in the link command line.  */
   var = alloca (name_len + 2);
+  strncpy (var, name, name_len);
   var[name_len++] = '=';
   var[name_len] = '\0';
   return _putenv (var);