Fix putenv and unsetenv on MS-Windows.

 src/w32.c (unsetenv): Return 0 if the input string is too long.

 nt/inc/ms-w32.h (sys_putenv): Add prototype.

Fixes: debbugs:13070

1 files changed, 1 insertions, 1 deletions

diff --git a/src/w32.c b/src/w32.c
index 203c5cd40ff..b6bb653369d 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1562,7 +1562,7 @@ unsetenv (const char *name)
   if (name_len > 32767)
     {
       errno = ENOMEM;
-      return -1;
+      return 0;
     }
   /* 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.  */