From bac58847fec9ea9876c35a65e9008a42a0566ddc Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Fri, 4 Nov 2022 16:50:37 +0000
Subject: [PATCH] Make P_InitMapData/dependents use partadd_earliestfile

---
 src/p_setup.c | 25 +++++++++++++------------
 src/w_wad.c   |  3 ++-
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/p_setup.c b/src/p_setup.c
index b08e75f01..94530ccc5 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -7766,20 +7766,9 @@ UINT8 P_InitMapData(boolean existingmapheaders)
 		name = mapheaderinfo[i]->lumpname;
 		maplump = W_CheckNumForMap(name);
 
-		// Doesn't exist?
-		if (maplump == INT16_MAX)
-		{
-#ifndef DEVELOP
-			if (!existingmapheaders)
-			{
-				I_Error("P_InitMapData: Base map %s has a header but no level\n", name);
-			}
-#endif
-			continue;
-		}
-
 		// Always check for cup cache reassociations.
 		// (The core assumption is that cups < headers.)
+		if (maplump != LUMPERROR || mapheaderinfo[i]->lumpnum != LUMPERROR)
 		{
 			cupheader_t *cup = kartcupheaders;
 			INT32 j;
@@ -7814,6 +7803,18 @@ UINT8 P_InitMapData(boolean existingmapheaders)
 			}
 		}
 
+		// Doesn't exist in this set of files?
+		if (maplump == LUMPERROR)
+		{
+#ifndef DEVELOP
+			if (!existingmapheaders)
+			{
+				I_Error("P_InitMapData: Base map %s has a header but no level\n", name);
+			}
+#endif
+			continue;
+		}
+
 		// No change?
 		if (mapheaderinfo[i]->lumpnum == maplump)
 			continue;
diff --git a/src/w_wad.c b/src/w_wad.c
index 8edbe74b6..e81879114 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -1324,6 +1324,7 @@ lumpnum_t W_CheckNumForMap(const char *name)
 	lumpnum_t check = INT16_MAX;
 	UINT32 uhash, hash = quickncasehash(name, LUMPNUMCACHENAME);
 	INT32 i;
+	UINT16 firstfile = (partadd_earliestfile == UINT16_MAX) ? 0 : partadd_earliestfile;
 
 	// Check the lumpnumcache first. Loop backwards so that we check
 	// most recent entries first
@@ -1339,7 +1340,7 @@ lumpnum_t W_CheckNumForMap(const char *name)
 
 	uhash = quickncasehash(name, 8); // Not a mistake, legacy system for short lumpnames
 
-	for (i = numwadfiles - 1; i >= 0; i--)
+	for (i = numwadfiles - 1; i >= firstfile; i--)
 	{
 		check = W_CheckNumForMapPwad(name, uhash, (UINT16)i, 0);