From e27ea76b8887c6d4c597054edf5beddc40100867 Mon Sep 17 00:00:00 2001
From: Sergey Larin <sergy.larin@gmail.com>
Date: Fri, 6 Aug 2021 10:54:26 +0300
Subject: [PATCH] The TStream.ReadBuffer and TStream.WriteBuffer methods have
 changed the Count parameter type to NativeInt. Changed the implementation of
 ReadBuffer, WriteBuffer so that the size of the blocks when calling Read and
 Write does not exceed High(Longint). Notes: - Thanks to this change, for
 example, a file larger than 2GB can be loaded into TMemoryStream. - The fact
 that the Count parameter has the NativeInt type is compatible with the latest
 versions of Delphi.

---
 rtl/objpas/classes/classesh.inc |  4 ++--
 rtl/objpas/classes/streams.inc  | 40 ++++++++++++++++-----------------
 2 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/rtl/objpas/classes/classesh.inc b/rtl/objpas/classes/classesh.inc
index d03cca3428..9925b99f6d 100644
--- a/rtl/objpas/classes/classesh.inc
+++ b/rtl/objpas/classes/classesh.inc
@@ -999,7 +999,7 @@ type
     function ReadData(var Buffer: TExtended80Rec): NativeInt; overload;
     function ReadData(var Buffer: TExtended80Rec; Count: NativeInt): NativeInt; overload;
 {$ENDIF}
-    procedure ReadBuffer(var Buffer; Count: Longint);
+    procedure ReadBuffer(var Buffer; Count: NativeInt);
     procedure ReadBuffer(var Buffer: TBytes; Count: NativeInt); overload;
     procedure ReadBuffer(var Buffer: TBytes; Offset, Count: NativeInt); overload;
 
@@ -1035,7 +1035,7 @@ type
     procedure ReadBufferData(var Buffer: TExtended80Rec); overload;
     procedure ReadBufferData(var Buffer: TExtended80Rec; Count: NativeInt); overload;
 {$ENDIF}
-    procedure WriteBuffer(const Buffer; Count: Longint);
+    procedure WriteBuffer(const Buffer; Count: NativeInt);
     procedure WriteBuffer(const Buffer: TBytes; Count: NativeInt); overload;
     procedure WriteBuffer(const Buffer: TBytes; Offset, Count: NativeInt); overload;
 
diff --git a/rtl/objpas/classes/streams.inc b/rtl/objpas/classes/streams.inc
index 5e5ac06769..9de20eca56 100644
--- a/rtl/objpas/classes/streams.inc
+++ b/rtl/objpas/classes/streams.inc
@@ -404,19 +404,19 @@ begin
 end;
 {$ENDIF}
 
-procedure TStream.ReadBuffer(var Buffer; Count: Longint);
-
-Var
-  r,t : longint;
-
+procedure TStream.ReadBuffer(var Buffer; Count: NativeInt);
+var
+  r,t: NativeInt;
 begin
   t:=0;
   repeat
-    r:=Read(PByte(@Buffer)[t],Count-t);
+    r:=Count-t;
+    if r>High(Longint) then r:=High(Longint);
+    r:=Read(PByte(@Buffer)[t],r);
     inc(t,r);
   until (t=Count) or (r<=0);
   if (t<Count) then
-    Raise EReadError.Create(SReadError);
+    raise EReadError.Create(SReadError);
 end;
 
 procedure TStream.ReadBuffer(var Buffer: TBytes; Count: NativeInt);
@@ -581,20 +581,20 @@ begin
 end;
 {$ENDIF}
 
-procedure TStream.WriteBuffer(const Buffer; Count: Longint);
-
+procedure TStream.WriteBuffer(const Buffer; Count: NativeInt);
 var
-  r,t : Longint;
-
-  begin
-    T:=0;
-    Repeat
-       r:=Write(PByte(@Buffer)[t],Count-t);
-       inc(t,r);
-    Until (t=count) or (r<=0);
-    if (t<Count) then
-       Raise EWriteError.Create(SWriteError);
-  end;
+  w,t: NativeInt;
+begin
+  t:=0;
+  repeat
+    w:=Count-t;
+    if w>High(Longint) then w:=High(Longint);
+    w:=Write(PByte(@Buffer)[t],w);
+    inc(t,w);
+  until (t=count) or (w<=0);
+  if (t<Count) then
+    raise EWriteError.Create(SWriteError);
+end;
 
 procedure TStream.WriteBuffer(const Buffer: TBytes; Count: NativeInt);
 begin