From 898745b144ec9a7a3fb1ad9d40266e41ddc4f530 Mon Sep 17 00:00:00 2001
From: Albert Cahalan <albert@users.sourceforge.net>
Date: Tue, 23 Nov 2004 01:58:56 +0000
Subject: [PATCH] half of the signed/unsigned warnings

---
 docs/CHANGES.txt |  3 +++
 src/tuxpaint.c   | 29 ++++++++++++++++++++++-------
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/docs/CHANGES.txt b/docs/CHANGES.txt
index 971812ea7..a58e49ce4 100644
--- a/docs/CHANGES.txt
+++ b/docs/CHANGES.txt
@@ -8,6 +8,9 @@ http://www.newbreedsoftware.com/tuxpaint/
 
 
 2004.November.22 (0.9.15)
+  * When using gcc, min() and max() do type checking.
+    Albert Cahalan <albert@users.sf.net>
+
   * Fixed many warnings.
     Albert Cahalan <albert@users.sf.net>
 
diff --git a/src/tuxpaint.c b/src/tuxpaint.c
index b1d02c0b5..af3661f1e 100644
--- a/src/tuxpaint.c
+++ b/src/tuxpaint.c
@@ -296,8 +296,23 @@ static void win32_perror(const char * const str)
 
 
 #ifndef WIN32
-#define min(a,b) ((a < b) ? a : b)
-#define max(a,b) ((a > b) ? a : b)
+#ifdef __GNUC__
+// This version has strict type checking for safety.
+// See the "unnecessary" pointer comparison. (from Linux)
+#define min(x,y) ({ \
+  typeof(x) _x = (x);     \
+  typeof(y) _y = (y);     \
+  (void) (&_x == &_y);            \
+  _x < _y ? _x : _y; })
+#define max(x,y) ({ \
+  typeof(x) _x = (x);     \
+  typeof(y) _y = (y);     \
+  (void) (&_x == &_y);            \
+  _x > _y ? _x : _y; })
+#else
+#define min(a,b) (((a) < (b)) ? (a) : (b))
+#define max(a,b) (((a) > (b)) ? (a) : (b))
+#endif
 #endif
 
 #define clamp(lo,value,hi)    (min(max(value,lo),hi))
@@ -3711,9 +3726,9 @@ static void blit_magic(int x, int y, int x2, int y2)
 		  SDL_GetRGB(getpixel(last, x + xx, y + yy), last->format,
 			     &r, &g, &b);
 
-		  r = min(r, 255);
-		  g = min(g, 255);
-		  b = min(b, 255);
+		  r = min(r, (Uint8)255);
+		  g = min(g, (Uint8)255);
+		  b = min(b, (Uint8)255);
 	
 		  if ((cur_magic == MAGIC_THIN && (((r + g + b) / 3) > 128)) ||
 		      (cur_magic == MAGIC_THICK && (((r + g + b) / 3) <= 128)))
@@ -3877,7 +3892,7 @@ static void show_version(void)
 static void show_usage(FILE * f, char * prg)
 {
   char * blank;
-  int i;
+  unsigned i;
 
   blank = strdup(prg);
 
@@ -12136,7 +12151,7 @@ static char * uppercase(char * str)
 static unsigned char * textdir(const unsigned char * const str)
 {
   unsigned char * dstr;
-  int i, j;
+  unsigned i, j;
 
 #ifdef DEBUG
   printf("ORIG_DIR: %s\n", str);