shithub: choc

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ref: 4f5b2b8a2f45229114e66e546d0795e6373afd88
parent: 1ae0fe698400cda907a1a9b55b50827b9931bd0a
author: Simon Howard <fraggle@soulsphere.org>
date: Thu Nov 24 15:20:28 EST 2016

hexen: Forbid demo extensions in WAD files.

Save and restore of these extension bits is a convenience for demo
playback purposes and not intended as an editing feature. If a demo
with such bits set is found inside a WAD file, we ignore them as
Vanilla Hexen would do.

Part of #817.

--- a/src/hexen/g_game.c
+++ b/src/hexen/g_game.c
@@ -2046,23 +2046,50 @@
     gameaction = ga_playdemo;
 }
 
+// Returns true if the given lump number corresponds to data from a .lmp
+// file, as opposed to a WAD.
+static boolean IsDemoFile(int lumpnum)
+{
+    char *lower;
+    boolean result;
+
+    lower = M_StringDuplicate(lumpinfo[lumpnum]->wad_file->path);
+    M_ForceLowercase(lower);
+    result = M_StringEndsWith(lower, ".lmp");
+    free(lower);
+
+    return result;
+}
+
 void G_DoPlayDemo(void)
 {
     skill_t skill;
-    int i, episode, map;
+    int i, lumpnum, episode, map;
 
     gameaction = ga_nothing;
-    demobuffer = demo_p = W_CacheLumpName(defdemoname, PU_STATIC);
+    lumpnum = W_GetNumForName(defdemoname);
+    demobuffer = W_CacheLumpNum(lumpnum, PU_STATIC);
+    demo_p = demobuffer;
     skill = *demo_p++;
     episode = *demo_p++;
     map = *demo_p++;
 
-    // Read special parameter bits: see G_RecordDemo() for details.
-    longtics = (*demo_p & DEMOHEADER_LONGTICS) != 0;
+    // When recording we store some extra options inside the upper bits
+    // of the player 1 present byte; this is equivalent to what vvHeretic
+    // does. However, only recognize these bits if they are in a demo file
+    // being played manually by the user; we ignore them (as is Vanilla
+    // behavior) if they are inside a WAD file.
+    // These extra bits are a convenience feature for demo playback, not
+    // an editing extension for WAD authors.
+    if (IsDemoFile(lumpnum))
+    {
+        // Read special parameter bits: see G_RecordDemo() for details.
+        longtics = (*demo_p & DEMOHEADER_LONGTICS) != 0;
 
-    // don't overwrite arguments from the command line
-    respawnparm |= (*demo_p & DEMOHEADER_RESPAWN) != 0;
-    nomonsters  |= (*demo_p & DEMOHEADER_NOMONSTERS) != 0;
+        // don't overwrite arguments from the command line
+        respawnparm |= (*demo_p & DEMOHEADER_RESPAWN) != 0;
+        nomonsters |= (*demo_p & DEMOHEADER_NOMONSTERS) != 0;
+    }
 
     for (i = 0; i < maxplayers; i++)
     {