Merge pull request #542 from chungy/final2_sky_fix

doom: the sky changes in final2 map11->12 and map20->21 transitions.

src/doom/g_game.c

@@ -612,6 +612,30 @@ void G_DoLoadLevel (void)
 
     skyflatnum = R_FlatNumForName(DEH_String(SKYFLATNAME));
 
+    // The "Sky never changes in Doom II" bug was fixed in
+    // the id Anthology version of doom2.exe for Final Doom.
+    if ((gamemode == commercial) && (gameversion == exe_final2))
+    {
+        char *skytexturename;
+
+        if (gamemap < 12)
+        {
+            skytexturename = "SKY1";
+        }
+        else if (gamemap < 21)
+        {
+            skytexturename = "SKY2";
+        }
+        else
+        {
+            skytexturename = "SKY3";
+        }
+
+        skytexturename = DEH_String(skytexturename);
+
+        skytexture = R_TextureNumForName(skytexturename);
+    }
+
     levelstarttic = gametic;        // for time calculation
     
     if (wipegamestate == GS_LEVEL)