--- a/configure.in	Wed Jan 13 07:52:53 2010 +0000
+++ b/configure.in	Wed Jan 13 08:06:32 2010 +0000
@@ -137,28 +137,27 @@
 dnl See whether we want assertions for debugging/sanity checking SDL itself.
 AC_ARG_ENABLE(assertions,
 AC_HELP_STRING([--enable-assertions],
-               [Enable internal sanity checks (yes/no/release/paranoid) [[default=release]]]),
-              , enable_assertions=release)
-sdl_valid_assertion_level=no
-if test x$enable_assertions = xno; then
-    sdl_valid_assertion_level=yes
-    AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 0)
-fi
-if test x$enable_assertions = xrelease; then
-    sdl_valid_assertion_level=yes
-    AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 1)
-fi
-if test x$enable_assertions = xyes; then
-    sdl_valid_assertion_level=yes
-    AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 2)
-fi
-if test x$enable_assertions = xparanoid; then
-    sdl_valid_assertion_level=yes
-    AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 3)
-fi
-if test x$sdl_valid_assertion_level = xno; then
-    AC_MSG_ERROR([*** unknown assertion level. stop.])
-fi
+               [Enable internal sanity checks (auto/disabled/release/enabled/paranoid) [[default=auto]]]),
+              , enable_assertions=auto)
+case "$enable_assertions" in
+    auto) # Use optimization settings to determine assertion level
+        ;;
+    disabled)
+        AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 0)
+        ;;
+    release)
+        AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 1)
+        ;;
+    enabled)
+        AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 2)
+        ;;
+    paranoid)
+        AC_DEFINE(SDL_DEFAULT_ASSERT_LEVEL, 3)
+        ;;
+    *)
+        AC_MSG_ERROR([*** unknown assertion level. stop.])
+        ;;
+esac
 
 dnl See whether we can use gcc style dependency tracking
 AC_ARG_ENABLE(dependency-tracking,

--- a/include/SDL_assert.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_assert.h	Wed Jan 13 08:06:32 2010 +0000
@@ -25,8 +25,10 @@
 #define _SDL_assert_h
 
 #ifndef SDL_ASSERT_LEVEL
-#if defined(_DEBUG) || defined(DEBUG) || \
-    (defined(__GNUC__) && !defined(__OPTIMIZE__))
+#ifdef SDL_DEFAULT_ASSERT_LEVEL
+#define SDL_ASSERT_LEVEL SDL_DEFAULT_ASSERT_LEVEL
+#elif defined(_DEBUG) || defined(DEBUG) || \
+      (defined(__GNUC__) && !defined(__OPTIMIZE__))
 #define SDL_ASSERT_LEVEL 2
 #else
 #define SDL_ASSERT_LEVEL 1

--- a/include/SDL_config_iphoneos.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_iphoneos.h	Wed Jan 13 08:06:32 2010 +0000
@@ -25,9 +25,6 @@
 
 #include "SDL_platform.h"
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

--- a/include/SDL_config_macosx.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_macosx.h	Wed Jan 13 08:06:32 2010 +0000
@@ -28,9 +28,6 @@
 /* This gets us MAC_OS_X_VERSION_MIN_REQUIRED... */
 #include <AvailabilityMacros.h>
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 /* This is a set of defines to configure the SDL features */
 
 #ifdef __LP64__

--- a/include/SDL_config_minimal.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_minimal.h	Wed Jan 13 08:06:32 2010 +0000
@@ -33,9 +33,6 @@
 
 #include <stdarg.h>
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

--- a/include/SDL_config_nintendods.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_nintendods.h	Wed Jan 13 08:06:32 2010 +0000
@@ -27,9 +27,6 @@
 
 /* This is a set of defines to configure the SDL features */
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

--- a/include/SDL_config_pandora.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_pandora.h	Wed Jan 13 08:06:32 2010 +0000
@@ -28,9 +28,6 @@
 /* General platform specific identifiers */
 #include "SDL_platform.h"
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 #define SDL_HAS_64BIT_TYPE 1
 #define SDL_BYTEORDER 1234
 

--- a/include/SDL_config_win32.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_win32.h	Wed Jan 13 08:06:32 2010 +0000
@@ -27,9 +27,6 @@
 
 /* This is a set of defines to configure the SDL features */
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 #if defined(__GNUC__) || defined(__DMC__) || defined(__WATCOMC__)
 #define HAVE_STDINT_H	1

--- a/include/SDL_config_wiz.h	Wed Jan 13 07:52:53 2010 +0000
+++ b/include/SDL_config_wiz.h	Wed Jan 13 08:06:32 2010 +0000
@@ -28,9 +28,6 @@
 /* General platform specific identifiers */
 #include "SDL_platform.h"
 
-/* SDL internal assertion support */
-#define SDL_DEFAULT_ASSERT_LEVEL 1
-
 /* Make sure that this isn't included by Visual C++ */
 #ifdef _MSC_VER
 #error You should copy include/SDL_config.h.default to include/SDL_config.h