From ad155c765b4c0c8df9555ebde908301a24d408db Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <sezeroz@gmail.com>
Date: Sun, 1 Jul 2018 09:50:47 +0300
Subject: [PATCH] make sure SDL_vsnprintf() nul terminates if it is using
 _vsnprintf

(bug #3769: backported commit 5e1341f8c467 for windows and watcom.)
---
 include/SDL_stdinc.h    |  4 ++--
 src/stdlib/SDL_string.c | 12 ++++++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/SDL_stdinc.h b/include/SDL_stdinc.h
index d6d29fb06..0df464784 100644
--- a/include/SDL_stdinc.h
+++ b/include/SDL_stdinc.h
@@ -575,13 +575,13 @@ extern DECLSPEC int SDLCALL SDL_strncasecmp(const char *str1, const char *str2,
 extern DECLSPEC int SDLCALL SDL_sscanf(const char *text, const char *fmt, ...);
 #endif
 
-#ifdef HAVE_SNPRINTF
+#if defined(HAVE_SNPRINTF) && !(defined(__WATCOMC__) || defined(_WIN32))
 #define SDL_snprintf    snprintf
 #else
 extern DECLSPEC int SDLCALL SDL_snprintf(char *text, size_t maxlen, const char *fmt, ...);
 #endif
 
-#ifdef HAVE_VSNPRINTF
+#if defined(HAVE_VSNPRINTF) && !(defined(__WATCOMC__) || defined(_WIN32))
 #define SDL_vsnprintf   vsnprintf
 #else
 extern DECLSPEC int SDLCALL SDL_vsnprintf(char *text, size_t maxlen, const char *fmt, va_list ap);
diff --git a/src/stdlib/SDL_string.c b/src/stdlib/SDL_string.c
index 25f1e6983..77bf2eba9 100644
--- a/src/stdlib/SDL_string.c
+++ b/src/stdlib/SDL_string.c
@@ -1013,7 +1013,7 @@ int SDL_sscanf(const char *text, const char *fmt, ...)
 }
 #endif
 
-#ifndef HAVE_SNPRINTF
+#if defined(__WATCOMC__) || defined(_WIN32) || !defined(HAVE_SNPRINTF)
 int SDL_snprintf(char *text, size_t maxlen, const char *fmt, ...)
 {
     va_list ap;
@@ -1027,7 +1027,15 @@ int SDL_snprintf(char *text, size_t maxlen, const char *fmt, ...)
 }
 #endif
 
-#ifndef HAVE_VSNPRINTF
+#if (defined(__WATCOMC__) || defined(_WIN32)) && defined(HAVE_LIBC)
+int SDL_vsnprintf(char *text, size_t maxlen, const char *fmt, va_list ap)
+{
+    int retval = _vsnprintf(text, maxlen, fmt, ap);
+    if (maxlen > 0) text[maxlen-1] = '\0';
+    if (retval < 0) retval = (int) maxlen;
+    return retval;
+}
+#elif !defined(HAVE_VSNPRINTF)
 static size_t SDL_PrintLong(char *text, long value, int radix, size_t maxlen)
 {
     char num[130];