Fix Haiku "unable to open saved files" bug

Appling patch from a92961004d
that fixes https://github.com/haikuports/haikuports/issues/3045

docs/AUTHORS.txt

@@ -1069,10 +1069,11 @@ $Id$
   * Maemo (Nokia 770 and N880) coding and builds
     Alessandro Pasotti <apasotti@gmail.com>
 
-  * BeOS coding and builds
+  * BeOS and Haiku coding and builds
     Luc 'Begasus' Schrijvers <begasus@gmail.com>
     Scott McCreary <scottmc@users.sourceforge.net>
     Marcin 'Shard' Konicki <shard at beosjournal.org>  [retired]
+    Gerasim Troeglazov <3dEyes@gmail.com>
 
   * Debian Linux packages
     Ben Armstrong <synrg@sanctuary.nslug.ns.ca>

docs/CHANGES.txt

@@ -9,7 +9,11 @@ http://www.tuxpaint.org/
 $Id$
 
 2020.June.22 (0.9.25)
-  * TBD
+  * Ports & Building
+    ----------------
+    * Corrections for Haiku not opening saved files.
+      (Ref: https://github.com/haikuports/haikuports/issues/3045)
+      Gerasim Troeglazov <3dEyes@gmail.com>
 
 2020.April.24 (0.9.24)
   * New tools

src/compiler.h

@@ -28,7 +28,6 @@
   $Id$
 */
 
-#ifndef __HAIKU__
 #ifdef __GNUC__
 // This version has strict type checking for safety.
 // See the "unnecessary" pointer comparison. (from Linux)
@@ -46,7 +45,6 @@
 #define min(a,b) (((a) < (b)) ? (a) : (b))
 #define max(a,b) (((a) > (b)) ? (a) : (b))
 #endif
-#endif /* Not Haiku */
 
 #define clamp(lo,value,hi)    (min(max(value,lo),hi))
 

src/tp_magic_api.h.in

@@ -10,7 +10,6 @@
 
 /* min() and max() variable comparisons: */
 
-#ifndef __HAIKU__
 #ifdef __GNUC__
 // This version has strict type checking for safety.
 // See the "unnecessary" pointer comparison. (from Linux)
@@ -28,7 +27,6 @@
 #define min(a,b) (((a) < (b)) ? (a) : (b))
 #define max(a,b) (((a) > (b)) ? (a) : (b))
 #endif
-#endif /* Not Haiku */
 
 /* clamp() returns 'value', unless it's less than 'lo' or greater than 'hi',
    in which cases it returns 'lo' or 'hi', respectively: */

src/tuxpaint.c

@@ -278,7 +278,7 @@ char *strcasestr(const char *haystack, const char *needle)
 #include <dirent.h>
 #include <signal.h>
 
-#if defined __BEOS__
+#if defined __BEOS__ || defined __HAIKU__
 
 /* BeOS */