From 267d3c2539f997afa8dd1f80a9db118bc6e167b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Strohh=C3=A4cker?=
 <c2woody@users.sourceforge.net>
Date: Thu, 13 Oct 2005 16:24:42 +0000
Subject: [PATCH] resize MCB to maximum if requested size is too big (DSPlay)

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2347
---
 src/dos/dos_memory.cpp | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/dos/dos_memory.cpp b/src/dos/dos_memory.cpp
index 0f97762d..6a3c47a8 100644
--- a/src/dos/dos_memory.cpp
+++ b/src/dos/dos_memory.cpp
@@ -191,6 +191,7 @@ bool DOS_ResizeMemory(Bit16u segment,Bit16u * blocks) {
 		mcb.SetPSPSeg(dos.psp());
 		return true;
 	}
+	/* MCB will grow, try to join with following MCB */
 	if (mcb.GetType()!=0x5a) {
 		if (mcb_next.GetPSPSeg()==MCB_FREE) {
 			total+=mcb_next.GetSize()+1;
@@ -198,6 +199,7 @@ bool DOS_ResizeMemory(Bit16u segment,Bit16u * blocks) {
 	}
 	if (*blocks<total) {
 		if (mcb.GetType()!=0x5a) {
+			/* save type of following MCB */
 			mcb.SetType(mcb_next.GetType());
 		}
 		mcb.SetSize(*blocks);
@@ -209,15 +211,19 @@ bool DOS_ResizeMemory(Bit16u segment,Bit16u * blocks) {
 		mcb.SetPSPSeg(dos.psp());
 		return true;
 	}
-	if (*blocks==total) {
-		if (mcb.GetType()!=0x5a) {
-			mcb.SetType(mcb_next.GetType());
-		}
-		mcb.SetSize(*blocks);
-		mcb.SetPSPSeg(dos.psp());
-		return true;
+
+	/* at this point: *blocks==total (fits) or *blocks>total,
+	   in the second case resize block to maximum */
+
+	if (mcb.GetType()!=0x5a) {
+		/* adjust type of joined MCB */
+		mcb.SetType(mcb_next.GetType());
 	}
-	*blocks=total;
+	mcb.SetSize(total);
+	mcb.SetPSPSeg(dos.psp());
+	if (*blocks==total) return true;	/* block fit exactly */
+
+	*blocks=total;	/* return maximum */
 	DOS_SetError(DOSERR_INSUFFICIENT_MEMORY);
 	return false;
 }