Add BFG edition workaround for options menu crash.

The BFG edition IWADs have their M_GDHIGH lumps changed to say
"Fullscreen:" instead of just "high". This breaks the options menu
which assumes a graphic that is not as wide.

In the same spirit as the title screen workaround, add a workaround
for this as well: use the message "on/off" graphics instead when we
are running using a BFG edition IWAD.

This fixes #341 (thanks Fabian Greffrath).

2 files changed, 28 insertions, 6 deletions

diff --git a/src/doom/doomstat.h b/src/doom/doomstat.h
index 9e09bb42..bb203e0d 100644
--- a/src/doom/doomstat.h
+++ b/src/doom/doomstat.h
@@ -66,6 +66,9 @@ extern GameMission_t	gamemission;
 extern GameVersion_t    gameversion;
 extern char            *gamedescription;
 
+// If true, we're using one of the mangled BFG edition IWADs.
+extern boolean bfgedition;
+
 // Convenience macro.
 // 'gamemission' can be equal to pack_chex or pack_hacx, but these are
 // just modified versions of doom and doom2, and should be interpreted
diff --git a/src/doom/m_menu.c b/src/doom/m_menu.c
index 4951d9a6..97c080c8 100644
--- a/src/doom/m_menu.c
+++ b/src/doom/m_menu.c
@@ -985,18 +985,37 @@ void M_Episode(int choice)
 //
 // M_Options
 //
-char    detailNames[2][9]	= {"M_GDHIGH","M_GDLOW"};
-char	msgNames[2][9]		= {"M_MSGOFF","M_MSGON"};
-
+static char *detailNames[2] = {"M_GDHIGH","M_GDLOW"};
+static char *msgNames[2] = {"M_MSGOFF","M_MSGON"};
 
 void M_DrawOptions(void)
 {
+    char *detail_patch;
+
     V_DrawPatchDirect(108, 15, W_CacheLumpName(DEH_String("M_OPTTTL"),
                                                PU_CACHE));
-	
+
+    // Workaround for BFG edition IWAD weirdness.
+    // The BFG edition doesn't have the "low detail" menu option (fair
+    // enough). But bizarrely, it reuses the M_GDHIGH patch as a label
+    // for the options menu (says "Fullscreen:"). Why the perpetrators
+    // couldn't just add a new graphic lump and had to reuse this one,
+    // I don't know.
+    //
+    // The end result is that M_GDHIGH is too wide and causes the game
+    // to crash. As a workaround to get a minimum level of support for
+    // the BFG edition IWADs, use the "ON"/"OFF" graphics instead.
+    if (bfgedition)
+    {
+        detail_patch = msgNames[detailLevel];
+    }
+    else
+    {
+        detail_patch = detailNames[detailLevel];
+    }
+
     V_DrawPatchDirect(OptionsDef.x + 175, OptionsDef.y + LINEHEIGHT * detail,
-		      W_CacheLumpName(DEH_String(detailNames[detailLevel]),
-			              PU_CACHE));
+		      W_CacheLumpName(DEH_String(detail_patch), PU_CACHE));
 
     V_DrawPatchDirect(OptionsDef.x + 120, OptionsDef.y + LINEHEIGHT * messages,
                       W_CacheLumpName(DEH_String(msgNames[showMessages]),