diff --git a/components/synedit/syneditpointclasses.pas b/components/synedit/syneditpointclasses.pas
index 0522841e4e..5a5c616ea8 100644
--- a/components/synedit/syneditpointclasses.pas
+++ b/components/synedit/syneditpointclasses.pas
@@ -176,6 +176,7 @@ type
     FLinePos: Integer;     // 1 based
     FCharPos: Integer;     // 1 based
     FLastCharPos: Integer; // used by KeepCaretX
+    FBytePos, FBytePosOffset: Integer;     // 1 based
     FOldLinePos: Integer; // 1 based
     FOldCharPos: Integer; // 1 based
     FAdjustToNextChar: Boolean;
@@ -185,6 +186,7 @@ type
     FTouched: Boolean;
 
     procedure AdjustToChar;
+    procedure UpdateBytePos;
     function GetOldLineBytePos: TPoint;
     function GetOldLineCharPos: TPoint;
     procedure InternalSetLineCharPos(NewLine, NewCharPos: Integer;
@@ -436,6 +438,8 @@ end;
 
 procedure TSynEditCaret.IncAutoMoveOnEdit;
 begin
+  if FAutoMoveOnEdit =0 then
+    UpdateBytePos;;
   inc(FAutoMoveOnEdit);
 end;
 
@@ -511,6 +515,11 @@ begin
   end;
 end;
 
+procedure TSynEditCaret.UpdateBytePos;
+begin
+  FBytePos := FLines.LogPhysConvertor.PhysicalToLogical(FLinePos-1, FCharPos, FBytePosOffset);
+end;
+
 function TSynEditCaret.GetOldLineBytePos: TPoint;
 begin
   Result := FLines.PhysicalToLogicalPos(OldLineCharPos);
@@ -589,6 +598,8 @@ begin
       AdjustToChar;
       if (not KeepLastCharPos) or (not FKeepCaretX) then
         FLastCharPos := FCharPos;
+      if FAutoMoveOnEdit <> 0 then
+        UpdateBytePos;
     end;
   finally
     Unlock;
@@ -703,10 +714,17 @@ procedure TSynEditCaret.DoLinesEdited(Sender: TSynEditStrings; aLinePos, aBytePo
     end;
   end;
 
+var
+  p: TPoint;
 begin
   if FAutoMoveOnEdit > 0 then begin
     IncForcePastEOL;
-    LineBytePos := AdjustPoint(LineBytePos);
+    p :=  AdjustPoint(Point(FBytePos, FLinePos));
+    p.x := FLines.LogPhysConvertor.LogicalToPhysical(p.y-1, p.x, FBytePosOffset);
+    FBytePos := -1;
+    LineCharPos := p;
+    if FBytePos < 0 then
+      UpdateBytePos;
     DecForcePastEOL;
   end;
 end;
diff --git a/components/synedit/synedittextbase.pas b/components/synedit/synedittextbase.pas
index c281cb3a8b..92a9f3993c 100644
--- a/components/synedit/synedittextbase.pas
+++ b/components/synedit/synedittextbase.pas
@@ -242,6 +242,7 @@ type
     function PhysicalToLogicalPos(const p: TPoint): TPoint;
     function PhysicalToLogicalCol(const Line: string;
                                   Index, PhysicalPos: integer): integer; virtual;
+    property LogPhysConvertor :TSynLogicalPhysicalConvertor read FLogPhysConvertor;
   public
     procedure EditInsert(LogX, LogY: Integer; AText: String); virtual; abstract;
     function  EditDelete(LogX, LogY, ByteLen: Integer): String; virtual; abstract;
@@ -469,11 +470,13 @@ procedure TSynLogicalPhysicalConvertor.PrepareWidthsForLine(AIndex: Integer;
 var
   LineLen: Integer;
   Line: PChar;
+//const dbg_cnt: integer = 0;
 begin
   if (not AForce) and (FCurrentLine = AIndex) and
      (FLines.TextChangeStamp = FTextChangeStamp) and (FLines.ViewChangeStamp = FViewChangeStamp)
   then begin
     //debugln(['**************** RE-USING widths: ', AIndex,' (',dbgs(Pointer(self)),')']);
+    //dbg_cnt := dbg_cnt + 1;
     exit;
   end;
 
@@ -498,6 +501,7 @@ begin
   //else begin
   //  debugln(['**************** COMPUTING widths: ', AIndex,' (',dbgs(Pointer(self)),') alloc=',FCurrentWidthsAlloc]);
   end;
+  //debugln(['**************** NEW for index:: ', AIndex,' (',dbgs(Pointer(self)),') after index: ', FCurrentLine, ' used ', dbg_cnt,' times // old-alloc=', FCurrentWidthsAlloc, '  new-len=',LineLen, '  viewchg:',dbgs(not(FViewChangeStamp=FLines.ViewChangeStamp)),' txtchg:',dbgs(not(FTextChangeStamp=FLines.TextChangeStamp))]); dbg_cnt := 0;
 
   FCurrentWidthsLen := LineLen;
   if LineLen > 0 then
diff --git a/components/synedit/synedittexttrimmer.pas b/components/synedit/synedittexttrimmer.pas
index 12b2a7e7fb..32242a5ba3 100644
--- a/components/synedit/synedittexttrimmer.pas
+++ b/components/synedit/synedittexttrimmer.pas
@@ -587,18 +587,23 @@ var
 begin
   if (not fEnabled) then exit;
   FIsTrimming := True;
-  IncViewChangeStamp;
   {$IFDEF SynTrimDebug}debugln(['--- Trimmer -- TrimAfterLock', ' fLineIndex=', fLineIndex, ' fSpaces=',length(fSpaces), '  Index=', Index, ' LockList=',fLockList.CommaText]);{$ENDIF}
   i := fLockList.IndexOfObject(TObject(Pointer(PtrUInt(fLineIndex))));
   if i >= 0 then begin
+    if fSpaces <> fLockList[i] then
+      IncViewChangeStamp;
     fSpaces:= fLockList[i];
     if (fLineIndex >= 0) and (fLineIndex < fSynStrings.Count) then
       fLineText := fSynStrings[fLineIndex];
     fLockList.Delete(i);
     DoCaretChanged(fCaret);
-  end;
+  end
+  else if fSpaces <> '' then
+    IncViewChangeStamp;
   FIsTrimming := True;
   BeginUpdate;
+  if fLockList.Count > 0 then
+    IncViewChangeStamp;
   try
     for i := 0 to fLockList.Count-1 do begin
       index := Integer(PtrUInt(Pointer(fLockList.Objects[i])));
diff --git a/components/synedit/test/testbase.pas b/components/synedit/test/testbase.pas
index db9b5e6f91..cc44ee6bd0 100644
--- a/components/synedit/test/testbase.pas
+++ b/components/synedit/test/testbase.pas
@@ -7,7 +7,7 @@ interface
 
 uses
   Classes, SysUtils, Forms, fpcunit, SynEdit, LCLType, LCLProc, math,
-  SynEditTypes, Clipbrd;
+  SynEditTypes, SynEditPointClasses, Clipbrd;
 
 type
 
@@ -24,6 +24,7 @@ type
     property ViewedTextBuffer;
     property TextBuffer;
     property TextView; // foldedview
+    property CaretObj: TSynEditCaret read GetCaretObj;
   end;
 
   { TTestBase }
@@ -318,6 +319,7 @@ end;
 procedure TTestBase.TestFail(Name, Func, Expect, Got: String; Result: Boolean = False);
 begin
   if Result then exit;
+  DebugLn(DbgStr(SynEdit.Text));
   if BaseTestName <> '' then
     Fail(Format('%s: %s (%s)%sExpected: %s%s     Got: %s', [BaseTestName, Name, Func, LineEnding, Expect, LineEnding, Got]))
   else
diff --git a/components/synedit/test/testbasicsynedit.pas b/components/synedit/test/testbasicsynedit.pas
index 5da92e3333..b4b8486ae9 100644
--- a/components/synedit/test/testbasicsynedit.pas
+++ b/components/synedit/test/testbasicsynedit.pas
@@ -28,6 +28,7 @@ type
     procedure TestEditEmpty;
     procedure TestEditTabs;
     procedure TestEditPhysicalLogical;
+    procedure TestCaretAutoMove;
   end;
 
 implementation
@@ -249,6 +250,65 @@ begin
 
 end;
 
+procedure TTestBasicSynEdit.TestCaretAutoMove;
+
+  procedure DoTest(name: string; y, x, insertY, insertX, InsertY2, InsertX2: integer;
+                   txt: string; expY, expX: Integer);
+  begin
+    name := name + ' y='+inttostr(y)+' x='+inttostr(x);
+    if y > 0 then begin
+      ReCreateEdit;
+      SynEdit.TabWidth := 6;
+      SetLines(['x', 'abc', ' ääX', #9'mn', 'abc'#9'de', #9'Xää.']);
+      SynEdit.CaretXY := Point(x, y);
+    end;
+
+    SynEdit.TextBetweenPointsEx[Point(insertX, insertY), point(insertX2, InsertY2), scamAdjust]
+      := txt;
+debugln(dbgstr(SynEdit.Text));
+    TestIsCaretPhys(name, expX, expY);
+  end;
+
+const
+  cr = LineEnding;
+begin
+
+
+  DoTest('simple insert',              2,2,   2,1,  2,1, 'X',      2,3);
+  DoTest('simple insert CR',           2,2,   2,1,  2,1, 'X'+cr,   3,2);
+  DoTest('simple insert CR+',          2,2,   2,1,  2,1, cr+'X',   3,3);
+  DoTest('simple delete',              2,2,   2,1,  2,2, '',       2,1);
+  DoTest('simple delete CR',           2,2,   1,2,  2,1, '',       1,3);
+  DoTest('+simple delete CR',          2,2,   1,1,  2,1, '',       1,2);
+
+  DoTest('simple insert (eol)',        2,4,   2,1,  2,1, 'X',   2,5);
+  DoTest('simple insert (past eol)',   2,7,   2,1,  2,1, 'X',   2,8);
+
+  DoTest('insert with tab',            4,8,   4,1,  4,1, 'X',      4,8);
+  DoTest('insert with tab (cont)',    -4,8,   4,2,  4,2, 'Y',      4,8);
+  DoTest('insert with tab (cont)',    -4,8,   4,3,  4,3, 'abc',    4,8);
+  DoTest('insert with tab (cont)',    -4,8,   4,6,  4,6, 'Z',      4,14);
+  DoTest('insert with tab (cont)',    -4,8,   4,7,  4,7, '.',      4,14);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,14);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+
+
+  SynEdit.CaretObj.IncAutoMoveOnEdit;
+  DoTest('insert with tab (am-block)',            4,8,   4,1,  4,1, 'X',      4,8);
+  DoTest('insert with tab (am-block) (cont)',    -4,8,   4,2,  4,2, 'Y',      4,8);
+  DoTest('insert with tab (am-block) (cont)',    -4,8,   4,3,  4,3, 'abc',    4,8);
+  DoTest('insert with tab (am-block) (cont)',    -4,8,   4,6,  4,6, 'Z',      4,14);
+  DoTest('insert with tab (am-block) (cont)',    -4,8,   4,7,  4,7, '.',      4,14);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,14);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+  DoTest('delete with tab (cont)',    -4,8,   4,1,  4,2, '',       4,8);
+  SynEdit.CaretObj.DecAutoMoveOnEdit;
+
+end;
+
 
 
 initialization