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, 3 deletions

diff --git a/src/doom/d_main.c b/src/doom/d_main.c
index 0cdb83d4..2a4fe236 100644
--- a/src/doom/d_main.c
+++ b/src/doom/d_main.c
@@ -384,7 +384,7 @@ void D_BindVariables(void)
     {
         char buf[12];
 
-        snprintf(buf, sizeof(buf), "chatmacro%i", i);
+        M_snprintf(buf, sizeof(buf), "chatmacro%i", i);
         M_BindVariable(buf, &chat_macros[i]);
     }
 }
@@ -669,8 +669,8 @@ static char *GetGameName(char *gamename)
             gamename_size = strlen(deh_sub) + 10;
             gamename = Z_Malloc(gamename_size, PU_STATIC, 0);
             version = G_VanillaVersionCode();
-            snprintf(gamename, gamename_size, deh_sub,
-                     version / 100, version % 100);
+            M_snprintf(gamename, gamename_size, deh_sub,
+                       version / 100, version % 100);
 
             while (gamename[0] != '\0' && isspace(gamename[0]))
             {