From ad6266815d87772126c33b581027e115139fa1c7 Mon Sep 17 00:00:00 2001
From: mattias <nc-gaertnma@netcologne.de>
Date: Wed, 25 Nov 2009 13:08:41 +0000
Subject: [PATCH] LCL: TCustomImageList: added Equals and comparing data with
 Ancestor

git-svn-id: trunk@22766 -
---
 lcl/imglist.pp          |  1 +
 lcl/include/imglist.inc | 33 +++++++++++++++++++++++++++------
 lcl/lresources.pp       | 28 ++++++++++++++++------------
 3 files changed, 44 insertions(+), 18 deletions(-)

diff --git a/lcl/imglist.pp b/lcl/imglist.pp
index aef0a442cf..18e53da23c 100644
--- a/lcl/imglist.pp
+++ b/lcl/imglist.pp
@@ -157,6 +157,7 @@ type
     procedure Assign(Source: TPersistent); override;
     procedure WriteData(AStream: TStream); virtual;
     procedure ReadData(AStream: TStream); virtual;
+    function Equals(Obj: TObject): boolean; override;
     procedure BeginUpdate;
     procedure EndUpdate;
 
diff --git a/lcl/include/imglist.inc b/lcl/include/imglist.inc
index 2f8bc36a89..d8f22b0dda 100644
--- a/lcl/include/imglist.inc
+++ b/lcl/include/imglist.inc
@@ -386,13 +386,9 @@ procedure TCustomImageList.DefineProperties(Filer: TFiler);
 
   function DoWrite: Boolean;
   begin
-   { if Filer.Ancestor <> nil then
-    begin
-      Result := (not (Filer.Ancestor is TCustomImageList) or
-        not Equal(TCustomImageList(Filer.Ancestor)));
-    end
+    if (Filer.Ancestor <> nil) and (Filer.Ancestor is TCustomImageList) then
+      Result :=  not Equals(Filer.Ancestor)
     else
-    }
       Result := Count > 0;
   end;
 
@@ -1180,6 +1176,31 @@ begin
   end;
 end;
 
+function TCustomImageList.Equals(Obj: TObject): boolean;
+var
+  SrcList: TCustomImageList;
+  CurStream: TMemoryStream;
+  SrcStream: TMemoryStream;
+begin
+  if Obj is TCustomImageList then begin
+    SrcList:=TCustomImageList(Obj);
+    Result:=false;
+    if SrcList.Count<>Count then exit;
+    if Count=0 then exit(true);
+    CurStream:=TMemoryStream.Create;
+    SrcStream:=TMemoryStream.Create;
+    try
+      WriteData(CurStream);
+      SrcList.WriteData(SrcStream);
+      Result:=CompareMemStreams(CurStream,SrcStream);
+    finally
+      SrcStream.Free;
+      CurStream.Free;
+    end;
+  end else
+    Result:=inherited Equals(Obj);
+end;
+
 {------------------------------------------------------------------------------
   Method:  TCustomImageList.RegisterChanges
   Params:  Value: a reference to changelink object
diff --git a/lcl/lresources.pp b/lcl/lresources.pp
index fb1a57e60f..cf7c79b1fe 100644
--- a/lcl/lresources.pp
+++ b/lcl/lresources.pp
@@ -1060,23 +1060,27 @@ end;
 function CompareMemStreams(Stream1, Stream2: TCustomMemoryStream
   ): boolean;
 var
-  Buffer1, Buffer2: array[1..1024] of byte;
-  BufLength: Integer;
-  Count: LongInt;
+  p1: Pointer;
+  p2: Pointer;
+  Cnt: Int64;
+  CurCnt: cardinal;
 begin
   if Stream1=Stream2 then exit(true);
   Result:=false;
   if (Stream1=nil) or (Stream2=nil) then exit;
   if Stream1.Size<>Stream2.Size then exit;
-  Stream1.Position:=0;
-  Stream2.Position:=0;
-  BufLength:=High(Buffer1)-Low(Buffer1)+1;
-  repeat
-    Count:=Stream1.Read(Buffer1[1],BufLength);
-    if Count=0 then exit(true);
-    Stream2.Read(Buffer2[1],BufLength);
-    if not CompareMem(@Buffer1[1],@Buffer2[1],Count) then exit;
-  until false;
+  Cnt:=Stream1.Size;
+  p1:=Stream1.Memory;
+  p2:=Stream2.Memory;
+  while Cnt>0 do begin
+    CurCnt:=Cnt;
+    if CurCnt>=High(Cardinal) then CurCnt:=High(Cardinal);
+    if not CompareMem(p1,p2,CurCnt) then exit;
+    inc(p1,CurCnt);
+    inc(p2,CurCnt);
+    dec(Cnt,CurCnt);
+  end;
+  Result:=true;
 end;
 
 procedure BinaryToLazarusResourceCode(BinStream,ResStream:TStream;