From fdb58291c49f9757f16f85d5fb2d46ab550ff32b Mon Sep 17 00:00:00 2001
From: Bart Oldeman <bart@dosemu.org>
Date: Sat, 11 Oct 2003 23:58:51 +0000
Subject: [PATCH] Fix FCB problems with int21/ah=27,28 (RandomBlockIO)

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@715 6ac86273-5f31-0410-b378-82cca8765d1b
---
 kernel/fcbfns.c   | 19 +++++++++++++------
 kernel/inthndlr.c |  4 ++--
 kernel/proto.h    |  2 +-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/kernel/fcbfns.c b/kernel/fcbfns.c
index 6942b13..0c71a95 100644
--- a/kernel/fcbfns.c
+++ b/kernel/fcbfns.c
@@ -337,19 +337,26 @@ void FcbCalcRec(xfcb FAR * lpXfcb)
   lpFcb->fcb_curec = lpFcb->fcb_rndm & 127;
 }
 
-UBYTE FcbRandomBlockIO(xfcb FAR * lpXfcb, COUNT nRecords, int mode)
+UBYTE FcbRandomBlockIO(xfcb FAR * lpXfcb, UWORD *nRecords, int mode)
 {
-  UCOUNT recno = 0;
-  UBYTE nErrorCode;
+  unsigned recno;
+  UBYTE nErrorCode = FCB_SUCCESS;
 
   FcbCalcRec(lpXfcb);
 
   /* Convert to fcb if necessary                                  */
   lpFcb = ExtFcbToFcb(lpXfcb);
 
-  do
-    nErrorCode = FcbReadWrite(lpXfcb, recno++, mode);
-  while ((--nRecords > 0) && (nErrorCode == 0));
+  for (recno = 0; recno < *nRecords; recno++)
+  {
+    nErrorCode = FcbReadWrite(lpXfcb, recno, mode);
+    /* end-of-file, partial read should count last record */
+    if (nErrorCode == FCB_ERR_EOF)
+      recno++;
+    if (nErrorCode != FCB_SUCCESS)
+      break;
+  }
+  *nRecords = recno;
 
   /* Now update the fcb                                           */
   lpFcb->fcb_rndm = FcbRec();
diff --git a/kernel/inthndlr.c b/kernel/inthndlr.c
index 556ea69..1290538 100644
--- a/kernel/inthndlr.c
+++ b/kernel/inthndlr.c
@@ -658,12 +658,12 @@ dispatch:
 
       /* Read random record(s) using FCB */
     case 0x27:
-      lr.AL = FcbRandomBlockIO(FP_DS_DX, lr.CX, XFR_READ);
+      lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_READ);
       break;
 
       /* Write random record(s) using FCB */
     case 0x28:
-      lr.AL = FcbRandomBlockIO(FP_DS_DX, lr.CX, XFR_WRITE);
+      lr.AL = FcbRandomBlockIO(FP_DS_DX, &lr.CX, XFR_WRITE);
       break;
 
       /* Parse File Name                                              */
diff --git a/kernel/proto.h b/kernel/proto.h
index c28c1ad..c82c76a 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -210,7 +210,7 @@ const BYTE FAR *GetNameField(const BYTE FAR * lpFileName, BYTE FAR * lpDestField
 UBYTE FcbReadWrite(xfcb FAR *, UCOUNT, int);
 UBYTE FcbGetFileSize(xfcb FAR * lpXfcb);
 void FcbSetRandom(xfcb FAR * lpXfcb);
-UBYTE FcbRandomBlockIO(xfcb FAR * lpXfcb, COUNT nRecords, int mode);
+UBYTE FcbRandomBlockIO(xfcb FAR * lpXfcb, UWORD *nRecords, int mode);
 UBYTE FcbRandomIO(xfcb FAR * lpXfcb, int mode);
 UBYTE FcbOpen(xfcb FAR * lpXfcb, unsigned flags);
 int FcbNameInit(fcb FAR * lpFcb, BYTE * pszBuffer, COUNT * pCurDrive);