From a0840d269546bc0b314dd2d0bcebe1785beb9f62 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Tue, 7 Jun 2011 21:10:04 +0200
Subject: [PATCH] FFI: Print NULL pointers as "cdata<... *>: NULL".

---
 src/lj_str.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/lj_str.c b/src/lj_str.c
index a5d894e0..cd3a8b69 100644
--- a/src/lj_str.c
+++ b/src/lj_str.c
@@ -360,6 +360,10 @@ const char *lj_str_pushvf(lua_State *L, const char *fmt, va_list argp)
       char buf[2+FMTP_CHARS];
       ptrdiff_t p = (ptrdiff_t)(va_arg(argp, void *));
       ptrdiff_t i, lasti = 2+FMTP_CHARS;
+      if (p == 0) {
+	addstr(L, sb, "NULL", 4);
+	break;
+      }
 #if LJ_64
       /* Shorten output for 64 bit pointers. */
       lasti = 2+2*4+((p >> 32) ? 2+2*(lj_fls((uint32_t)(p >> 32))>>3) : 0);