Replace all snprintf() calls with M_snprintf().

The Windows API has an _snprintf function that is not the same as
Unix's snprintf(): if the string is truncated then no trailing NUL
character is appended. This makes the function unsafe. Define a
replacement/wrapper called M_snprintf that works the same but always
appends a trailing NUL, for safety on Windows and other OSes that
behave like this.

Do the same thing for vsnprintf(), and update HACKING to list
snprintf/vsnprintf as forbidden functions. This fixes #375;
thanks to Quasar for pointing out the different behavior of these
functions.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/hexen/p_spec.c b/src/hexen/p_spec.c
index 06a4a6ff..58f3defe 100644
--- a/src/hexen/p_spec.c
+++ b/src/hexen/p_spec.c
@@ -27,6 +27,7 @@
 
 #include "h2def.h"
 #include "i_system.h"
+#include "m_misc.h"
 #include "p_local.h"
 #include "s_sound.h"
 
@@ -428,8 +429,8 @@ static boolean CheckedLockedDoor(mobj_t * mo, byte lock)
     }
     if (!(mo->player->keys & (1 << (lock - 1))))
     {
-        snprintf(LockedBuffer, sizeof(LockedBuffer),
-                 "YOU NEED THE %s\n", TextKeyMessages[lock - 1]);
+        M_snprintf(LockedBuffer, sizeof(LockedBuffer),
+                   "YOU NEED THE %s\n", TextKeyMessages[lock - 1]);
         P_SetMessage(mo->player, LockedBuffer, true);
         S_StartSound(mo, SFX_DOOR_LOCKED);
         return false;