PR#331: for Visual Studio, use a snprintf/vsnprintf wrapper that ensures the string is terminated.

json_object.c

@@ -31,13 +31,7 @@
 #include "json_util.h"
 #include "math_compat.h"
 #include "strdup_compat.h"
-
-#if !defined(HAVE_SNPRINTF) && defined(_MSC_VER)
-  /* MSC has the version as _snprintf */
-# define snprintf _snprintf
-#elif !defined(HAVE_SNPRINTF)
-# error You do not have snprintf on your system.
-#endif /* HAVE_SNPRINTF */
+#include "snprintf_compat.h"
 
 // Don't define this.  It's not thread-safe.
 /* #define REFCOUNT_DEBUG 1 */

json_util.c

@@ -48,12 +48,7 @@
 # define open _open
 #endif
 
-#if !defined(HAVE_SNPRINTF) && defined(_MSC_VER)
-  /* MSC has the version as _snprintf */
-# define snprintf _snprintf
-#elif !defined(HAVE_SNPRINTF)
-# error You do not have snprintf on your system.
-#endif /* HAVE_SNPRINTF */
+#include "snprintf_compat.h"
 
 #include "debug.h"
 #include "printbuf.h"

printbuf.c

@@ -27,6 +27,7 @@
 
 #include "debug.h"
 #include "printbuf.h"
+#include "snprintf_compat.h"
 #include "vasprintf_compat.h"
 
 static int printbuf_extend(struct printbuf *p, int min_size);

snprintf_compat.h

@@ -0,0 +1,36 @@
+#ifndef __snprintf_compat_h
+#define __snprintf_compat_h
+
+/*
+ * Microsoft's _vsnprintf and _snprint don't always terminate
+ * the string, so use wrappers that ensure that.
+ */
+
+#include <stdarg.h>
+
+#if !defined(HAVE_SNPRINTF) && defined(_MSC_VER)
+static int json_c_vsnprintf(char *str, size_t size, const char *format, va_list ap)
+{
+	int ret;
+	ret = _vsnprintf(str, size, format, ap);
+	str[size - 1] = '\0';
+	return ret;
+}
+#define vsnprintf json_c_vsnprintf
+
+static int json_c_snprintf(char *str, size_t size, const char *format, ...)
+{
+	va_list ap;
+	int ret;
+	va_start(ap, format);
+	ret = json_c_vsnprintf(str, size, format, ap);
+	va_end(ap);
+	return ret;
+}
+#define snprintf json_c_snprintf
+
+#elif !defined(HAVE_SNPRINTF) /* !HAVE_SNPRINTF */
+# error Need vsnprintf!
+#endif /* !HAVE_SNPRINTF && defined(WIN32) */
+
+#endif /* __snprintf_compat_h */

tests/test_locale.c

@@ -7,6 +7,7 @@
 #include "config.h"
 #include "json.h"
 #include "json_tokener.h"
+#include "snprintf_compat.h"
 
 #ifdef HAVE_LOCALE_H
 #include <locale.h>

vasprintf_compat.h

@@ -1,11 +1,7 @@
 #ifndef __vasprintf_compat_h
 #define __vasprintf_compat_h
 
-#if !defined(HAVE_VSNPRINTF) && defined(_MSC_VER)
-# define vsnprintf _vsnprintf
-#elif !defined(HAVE_VSNPRINTF) /* !HAVE_VSNPRINTF */
-# error Need vsnprintf!
-#endif /* !HAVE_VSNPRINTF && defined(WIN32) */
+#include "snprintf_compat.h"
 
 #if !defined(HAVE_VASPRINTF)
 /* CAW: compliant version of vasprintf */