diff --git a/ide/diffdialog.lfm b/ide/diffdialog.lfm
index 3da9ff7df3..2a2b7f7497 100644
--- a/ide/diffdialog.lfm
+++ b/ide/diffdialog.lfm
@@ -1,21 +1,20 @@
 object DiffDlg: TDiffDlg
-  Left = 298
+  Left = 300
   Height = 505
-  Top = 132
+  Top = 147
   Width = 598
   HelpType = htKeyword
-  ActiveControl = Text1Combobox
   BorderIcons = [biSystemMenu]
   Caption = 'Diff dialog'
   ClientHeight = 505
   ClientWidth = 598
   Position = poScreenCenter
-  LCLVersion = '0.9.27'
+  LCLVersion = '0.9.29'
   object Text1GroupBox: TGroupBox
     AnchorSideLeft.Control = Owner
     AnchorSideTop.Control = Owner
     Left = 6
-    Height = 74
+    Height = 78
     Top = 6
     Width = 586
     Align = alTop
@@ -23,7 +22,7 @@ object DiffDlg: TDiffDlg
     AutoSize = True
     BorderSpacing.Around = 6
     Caption = 'Text1GroupBox'
-    ClientHeight = 56
+    ClientHeight = 60
     ClientWidth = 582
     TabOrder = 0
     object Text1Combobox: TComboBox
@@ -31,16 +30,14 @@ object DiffDlg: TDiffDlg
       AnchorSideTop.Control = Text1GroupBox
       AnchorSideRight.Control = Text1FileOpenButton
       Left = 6
-      Height = 21
+      Height = 23
       Top = 6
       Width = 532
       Anchors = [akTop, akLeft, akRight]
-      AutoComplete = False
       BorderSpacing.Left = 6
       BorderSpacing.Top = 6
       BorderSpacing.Right = 6
-      ItemHeight = 13
-      ItemWidth = 0
+      ItemHeight = 15
       OnChange = Text1ComboboxChange
       TabOrder = 0
       Text = 'Text1Combobox'
@@ -50,8 +47,8 @@ object DiffDlg: TDiffDlg
       AnchorSideTop.Control = Text1Combobox
       AnchorSideTop.Side = asrBottom
       Left = 6
-      Height = 17
-      Top = 33
+      Height = 19
+      Top = 35
       Width = 490
       Anchors = [akTop, akLeft, akRight]
       BorderSpacing.Top = 6
@@ -67,7 +64,7 @@ object DiffDlg: TDiffDlg
       AnchorSideBottom.Control = Text1Combobox
       AnchorSideBottom.Side = asrBottom
       Left = 544
-      Height = 21
+      Height = 23
       Top = 6
       Width = 32
       Anchors = [akTop, akRight, akBottom]
@@ -79,14 +76,14 @@ object DiffDlg: TDiffDlg
   end
   object Text2GroupBox: TGroupBox
     Left = 6
-    Height = 74
-    Top = 86
+    Height = 78
+    Top = 90
     Width = 586
     Align = alTop
     AutoSize = True
     BorderSpacing.Around = 6
     Caption = 'Text2GroupBox'
-    ClientHeight = 56
+    ClientHeight = 60
     ClientWidth = 582
     TabOrder = 1
     object Text2Combobox: TComboBox
@@ -94,16 +91,14 @@ object DiffDlg: TDiffDlg
       AnchorSideTop.Control = Text2GroupBox
       AnchorSideRight.Control = Text2FileOpenButton
       Left = 6
-      Height = 21
+      Height = 23
       Top = 6
       Width = 532
       Anchors = [akTop, akLeft, akRight]
-      AutoComplete = False
       BorderSpacing.Left = 6
       BorderSpacing.Top = 6
       BorderSpacing.Right = 6
-      ItemHeight = 13
-      ItemWidth = 0
+      ItemHeight = 15
       OnChange = Text2ComboboxChange
       TabOrder = 0
       Text = 'Text2Combobox'
@@ -113,8 +108,8 @@ object DiffDlg: TDiffDlg
       AnchorSideTop.Control = Text2Combobox
       AnchorSideTop.Side = asrBottom
       Left = 6
-      Height = 17
-      Top = 33
+      Height = 19
+      Top = 35
       Width = 490
       Anchors = [akTop, akLeft, akRight]
       BorderSpacing.Top = 6
@@ -130,7 +125,7 @@ object DiffDlg: TDiffDlg
       AnchorSideBottom.Control = Text2Combobox
       AnchorSideBottom.Side = asrBottom
       Left = 544
-      Height = 21
+      Height = 23
       Top = 6
       Width = 32
       Anchors = [akTop, akRight, akBottom]
@@ -166,14 +161,14 @@ object DiffDlg: TDiffDlg
     Columns = 2
     TabOrder = 2
   end
-  object DiffSynEdit: TSynEdit
+  inline DiffSynEdit: TSynEdit
     AnchorSideLeft.Control = Owner
     AnchorSideTop.Control = Text2GroupBox
     AnchorSideRight.Control = Owner
     AnchorSideRight.Side = asrBottom
     Left = 6
-    Height = 186
-    Top = 166
+    Height = 178
+    Top = 174
     Width = 586
     Align = alTop
     BorderSpacing.Around = 6
@@ -187,340 +182,487 @@ object DiffDlg: TDiffDlg
     ParentFont = False
     TabOrder = 3
     BookMarkOptions.Xoffset = -18
-    BookMarkOptions.OnChange = nil
     Gutter.Visible = False
     Gutter.Width = 0
+    Gutter.MouseActions = <    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbLeft
+        ClickCount = ccAny
+        ClickDir = cdDown
+        Command = 13
+        MoveCaret = False
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbRight
+        ClickCount = ccSingle
+        ClickDir = cdUp
+        Command = 12
+        MoveCaret = False
+        Option = 0
+        Priority = 0
+      end>
+    Highlighter = SynDiffSyn1
     Keystrokes = <    
       item
-        Command = 3
+        Command = ecUp
         ShortCut = 38
       end    
       item
-        Command = 103
+        Command = ecSelUp
         ShortCut = 8230
       end    
       item
-        Command = 211
+        Command = ecScrollUp
         ShortCut = 16422
       end    
       item
-        Command = 4
+        Command = ecDown
         ShortCut = 40
       end    
       item
-        Command = 104
+        Command = ecSelDown
         ShortCut = 8232
       end    
       item
-        Command = 212
+        Command = ecScrollDown
         ShortCut = 16424
       end    
       item
-        Command = 1
+        Command = ecLeft
         ShortCut = 37
       end    
       item
-        Command = 101
+        Command = ecSelLeft
         ShortCut = 8229
       end    
       item
-        Command = 5
+        Command = ecWordLeft
         ShortCut = 16421
       end    
       item
-        Command = 105
+        Command = ecSelWordLeft
         ShortCut = 24613
       end    
       item
-        Command = 2
+        Command = ecRight
         ShortCut = 39
       end    
       item
-        Command = 102
+        Command = ecSelRight
         ShortCut = 8231
       end    
       item
-        Command = 6
+        Command = ecWordRight
         ShortCut = 16423
       end    
       item
-        Command = 106
+        Command = ecSelWordRight
         ShortCut = 24615
       end    
       item
-        Command = 10
+        Command = ecPageDown
         ShortCut = 34
       end    
       item
-        Command = 110
+        Command = ecSelPageDown
         ShortCut = 8226
       end    
       item
-        Command = 14
+        Command = ecPageBottom
         ShortCut = 16418
       end    
       item
-        Command = 114
+        Command = ecSelPageBottom
         ShortCut = 24610
       end    
       item
-        Command = 9
+        Command = ecPageUp
         ShortCut = 33
       end    
       item
-        Command = 109
+        Command = ecSelPageUp
         ShortCut = 8225
       end    
       item
-        Command = 13
+        Command = ecPageTop
         ShortCut = 16417
       end    
       item
-        Command = 113
+        Command = ecSelPageTop
         ShortCut = 24609
       end    
       item
-        Command = 7
+        Command = ecLineStart
         ShortCut = 36
       end    
       item
-        Command = 107
+        Command = ecSelLineStart
         ShortCut = 8228
       end    
       item
-        Command = 15
+        Command = ecEditorTop
         ShortCut = 16420
       end    
       item
-        Command = 115
+        Command = ecSelEditorTop
         ShortCut = 24612
       end    
       item
-        Command = 8
+        Command = ecLineEnd
         ShortCut = 35
       end    
       item
-        Command = 108
+        Command = ecSelLineEnd
         ShortCut = 8227
       end    
       item
-        Command = 16
+        Command = ecEditorBottom
         ShortCut = 16419
       end    
       item
-        Command = 116
+        Command = ecSelEditorBottom
         ShortCut = 24611
       end    
       item
-        Command = 223
+        Command = ecToggleMode
         ShortCut = 45
       end    
       item
-        Command = 201
+        Command = ecCopy
         ShortCut = 16429
       end    
       item
-        Command = 604
+        Command = ecPaste
         ShortCut = 8237
       end    
       item
-        Command = 502
+        Command = ecDeleteChar
         ShortCut = 46
       end    
       item
-        Command = 603
+        Command = ecCut
         ShortCut = 8238
       end    
       item
-        Command = 501
+        Command = ecDeleteLastChar
         ShortCut = 8
       end    
       item
-        Command = 501
+        Command = ecDeleteLastChar
         ShortCut = 8200
       end    
       item
-        Command = 504
+        Command = ecDeleteLastWord
         ShortCut = 16392
       end    
       item
-        Command = 601
+        Command = ecUndo
         ShortCut = 32776
       end    
       item
-        Command = 602
+        Command = ecRedo
         ShortCut = 40968
       end    
       item
-        Command = 509
+        Command = ecLineBreak
         ShortCut = 13
       end    
       item
-        Command = 199
+        Command = ecSelectAll
         ShortCut = 16449
       end    
       item
-        Command = 201
+        Command = ecCopy
         ShortCut = 16451
       end    
       item
-        Command = 610
+        Command = ecBlockIndent
         ShortCut = 24649
       end    
       item
-        Command = 509
+        Command = ecLineBreak
         ShortCut = 16461
       end    
       item
-        Command = 510
+        Command = ecInsertLine
         ShortCut = 16462
       end    
       item
-        Command = 503
+        Command = ecDeleteWord
         ShortCut = 16468
       end    
       item
-        Command = 611
+        Command = ecBlockUnindent
         ShortCut = 24661
       end    
       item
-        Command = 604
+        Command = ecPaste
         ShortCut = 16470
       end    
       item
-        Command = 603
+        Command = ecCut
         ShortCut = 16472
       end    
       item
-        Command = 507
+        Command = ecDeleteLine
         ShortCut = 16473
       end    
       item
-        Command = 506
+        Command = ecDeleteEOL
         ShortCut = 24665
       end    
       item
-        Command = 601
+        Command = ecUndo
         ShortCut = 16474
       end    
       item
-        Command = 602
+        Command = ecRedo
         ShortCut = 24666
       end    
       item
-        Command = 301
+        Command = ecGotoMarker0
         ShortCut = 16432
       end    
       item
-        Command = 302
+        Command = ecGotoMarker1
         ShortCut = 16433
       end    
       item
-        Command = 303
+        Command = ecGotoMarker2
         ShortCut = 16434
       end    
       item
-        Command = 304
+        Command = ecGotoMarker3
         ShortCut = 16435
       end    
       item
-        Command = 305
+        Command = ecGotoMarker4
         ShortCut = 16436
       end    
       item
-        Command = 306
+        Command = ecGotoMarker5
         ShortCut = 16437
       end    
       item
-        Command = 307
+        Command = ecGotoMarker6
         ShortCut = 16438
       end    
       item
-        Command = 308
+        Command = ecGotoMarker7
         ShortCut = 16439
       end    
       item
-        Command = 309
+        Command = ecGotoMarker8
         ShortCut = 16440
       end    
       item
-        Command = 310
+        Command = ecGotoMarker9
         ShortCut = 16441
       end    
       item
-        Command = 351
+        Command = ecSetMarker0
         ShortCut = 24624
       end    
       item
-        Command = 352
+        Command = ecSetMarker1
         ShortCut = 24625
       end    
       item
-        Command = 353
+        Command = ecSetMarker2
         ShortCut = 24626
       end    
       item
-        Command = 354
+        Command = ecSetMarker3
         ShortCut = 24627
       end    
       item
-        Command = 355
+        Command = ecSetMarker4
         ShortCut = 24628
       end    
       item
-        Command = 356
+        Command = ecSetMarker5
         ShortCut = 24629
       end    
       item
-        Command = 357
+        Command = ecSetMarker6
         ShortCut = 24630
       end    
       item
-        Command = 358
+        Command = ecSetMarker7
         ShortCut = 24631
       end    
       item
-        Command = 359
+        Command = ecSetMarker8
         ShortCut = 24632
       end    
       item
-        Command = 360
+        Command = ecSetMarker9
         ShortCut = 24633
       end    
       item
-        Command = 231
+        Command = ecNormalSelect
         ShortCut = 24654
       end    
       item
-        Command = 232
+        Command = ecColumnSelect
         ShortCut = 24643
       end    
       item
-        Command = 233
+        Command = ecLineSelect
         ShortCut = 24652
       end    
       item
-        Command = 612
+        Command = ecTab
         ShortCut = 9
       end    
       item
-        Command = 613
+        Command = ecShiftTab
         ShortCut = 8201
       end    
       item
-        Command = 250
+        Command = ecMatchBracket
         ShortCut = 24642
       end>
+    MouseActions = <    
+      item
+        Shift = []
+        ShiftMask = [ssShift, ssAlt]
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 1
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = [ssShift]
+        ShiftMask = [ssShift, ssAlt]
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 1
+        MoveCaret = True
+        Option = 1
+        Priority = 0
+      end    
+      item
+        Shift = [ssAlt]
+        ShiftMask = [ssShift, ssAlt]
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 3
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = [ssShift, ssAlt]
+        ShiftMask = [ssShift, ssAlt]
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 3
+        MoveCaret = True
+        Option = 1
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbRight
+        ClickCount = ccSingle
+        ClickDir = cdUp
+        Command = 12
+        MoveCaret = False
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbLeft
+        ClickCount = ccDouble
+        ClickDir = cdDown
+        Command = 6
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbLeft
+        ClickCount = ccTriple
+        ClickDir = cdDown
+        Command = 7
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbLeft
+        ClickCount = ccQuad
+        ClickDir = cdDown
+        Command = 8
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbMiddle
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 10
+        MoveCaret = True
+        Option = 0
+        Priority = 0
+      end    
+      item
+        Shift = [ssCtrl]
+        ShiftMask = [ssShift, ssAlt, ssCtrl]
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdUp
+        Command = 11
+        MoveCaret = False
+        Option = 0
+        Priority = 0
+      end>
+    MouseSelActions = <    
+      item
+        Shift = []
+        ShiftMask = []
+        Button = mbLeft
+        ClickCount = ccSingle
+        ClickDir = cdDown
+        Command = 9
+        MoveCaret = False
+        Option = 0
+        Priority = 0
+      end>
     Lines.Strings = (
       'DiffSynEdit'
     )
     BracketHighlightStyle = sbhsBoth
-    object TSynGutterPartList
+    inline TSynGutterPartList
       object TSynGutterMarks
         Width = 23
       end
       object TSynGutterLineNumber
         Width = 25
+        MouseActions = <>
         MarkupInfo.Background = clBtnFace
         MarkupInfo.Foreground = clNone
         DigitCount = 2
@@ -537,8 +679,88 @@ object DiffDlg: TDiffDlg
         Width = 2
       end
       object TSynGutterCodeFolding
+        MouseActions = <        
+          item
+            Shift = []
+            ShiftMask = []
+            Button = mbRight
+            ClickCount = ccSingle
+            ClickDir = cdUp
+            Command = 16
+            MoveCaret = False
+            Option = 0
+            Priority = 0
+          end        
+          item
+            Shift = []
+            ShiftMask = [ssShift]
+            Button = mbMiddle
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 14
+            MoveCaret = False
+            Option = 0
+            Priority = 0
+          end        
+          item
+            Shift = [ssShift]
+            ShiftMask = [ssShift]
+            Button = mbMiddle
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 14
+            MoveCaret = False
+            Option = 1
+            Priority = 0
+          end        
+          item
+            Shift = []
+            ShiftMask = []
+            Button = mbLeft
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 0
+            MoveCaret = False
+            Option = 0
+            Priority = 0
+          end>
         MarkupInfo.Background = clNone
         MarkupInfo.Foreground = clGray
+        MouseActionsExpanded = <        
+          item
+            Shift = []
+            ShiftMask = []
+            Button = mbLeft
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 14
+            MoveCaret = False
+            Option = 0
+            Priority = 0
+          end>
+        MouseActionsCollapsed = <        
+          item
+            Shift = [ssCtrl]
+            ShiftMask = [ssCtrl]
+            Button = mbLeft
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 15
+            MoveCaret = False
+            Option = 0
+            Priority = 0
+          end        
+          item
+            Shift = []
+            ShiftMask = [ssCtrl]
+            Button = mbLeft
+            ClickCount = ccAny
+            ClickDir = cdDown
+            Command = 15
+            MoveCaret = False
+            Option = 1
+            Priority = 0
+          end>
       end
     end
   end
@@ -546,10 +768,10 @@ object DiffDlg: TDiffDlg
     AnchorSideRight.Control = CloseButton
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 445
-    Height = 23
-    Top = 476
-    Width = 70
+    Left = 440
+    Height = 25
+    Top = 474
+    Width = 72
     Anchors = [akRight, akBottom]
     AutoSize = True
     BorderSpacing.Around = 6
@@ -562,10 +784,10 @@ object DiffDlg: TDiffDlg
     AnchorSideRight.Control = SaveDiffButton
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 317
-    Height = 23
-    Top = 476
-    Width = 122
+    Left = 302
+    Height = 25
+    Top = 474
+    Width = 132
     Anchors = [akRight, akBottom]
     AutoSize = True
     BorderSpacing.Around = 6
@@ -579,10 +801,10 @@ object DiffDlg: TDiffDlg
     AnchorSideRight.Side = asrBottom
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 521
+    Left = 518
     Height = 26
     Top = 473
-    Width = 71
+    Width = 74
     Anchors = [akRight, akBottom]
     AutoSize = True
     BorderSpacing.Around = 6
@@ -600,7 +822,7 @@ object DiffDlg: TDiffDlg
     Left = 6
     Height = 26
     Top = 473
-    Width = 66
+    Width = 70
     Anchors = [akLeft, akBottom]
     AutoSize = True
     BorderSpacing.Around = 6
@@ -624,4 +846,9 @@ object DiffDlg: TDiffDlg
     left = 459
     top = 12
   end
+  object SynDiffSyn1: TSynDiffSyn
+    Enabled = False
+    left = 104
+    top = 240
+  end
 end
diff --git a/ide/diffdialog.pas b/ide/diffdialog.pas
index 7e5a51ac1b..5a567af00d 100644
--- a/ide/diffdialog.pas
+++ b/ide/diffdialog.pas
@@ -42,7 +42,7 @@ interface
 uses
   Classes, SysUtils, Math, Forms, Controls, Buttons, StdCtrls, FileUtil,
   LazarusIDEStrConsts, EditorOptions, IDEWindowIntf, LCLType,
-  InputHistory, DiffPatch, ExtCtrls, Dialogs, SynEdit, IDEContextHelpEdit,
+  InputHistory, DiffPatch, ExtCtrls, Dialogs, SynEdit, SynHighlighterDiff, IDEContextHelpEdit,
   SourceEditor;
 
 type
@@ -82,6 +82,7 @@ type
     DiffSynEdit: TSynEdit;
     OpenInEditorButton: TBitBtn;
     SaveDiffButton: TBitBtn;
+    SynDiffSyn1: TSynDiffSyn;
     Text1FileOpenButton: TButton;
     dlgSave: TSaveDialog;
     dlgOpen: TOpenDialog;
diff --git a/ide/diskdiffsdialog.lfm b/ide/diskdiffsdialog.lfm
index a62816e754..abcf6b89eb 100644
--- a/ide/diskdiffsdialog.lfm
+++ b/ide/diskdiffsdialog.lfm
@@ -3,7 +3,6 @@ object DiskDiffsDlg: TDiskDiffsDlg
   Height = 354
   Top = 379
   Width = 600
-  ActiveControl = FilesListBox
   Caption = 'DiskDiffsDlg'
   ClientHeight = 354
   ClientWidth = 600
@@ -22,12 +21,11 @@ object DiskDiffsDlg: TDiskDiffsDlg
     ItemHeight = 0
     OnMouseUp = FilesListBoxMouseUp
     TabOrder = 0
-    TopIndex = -1
   end
   inline DiffSynEdit: TSynEdit
     AnchorSideBottom.Control = CheckDiskChangesWithLoadingCheckBox
     Left = 6
-    Height = 182
+    Height = 189
     Top = 97
     Width = 588
     Align = alTop
@@ -67,6 +65,7 @@ object DiskDiffsDlg: TDiskDiffsDlg
         Option = 0
         Priority = 0
       end>
+    Highlighter = SynDiffSyn1
     Keystrokes = <    
       item
         Command = ecUp
@@ -521,7 +520,7 @@ object DiskDiffsDlg: TDiskDiffsDlg
         Width = 23
       end
       object SynGutterLineNumber1: TSynGutterLineNumber
-        Width = 15
+        Width = 25
         MouseActions = <>
         MarkupInfo.Background = clBtnFace
         MarkupInfo.Foreground = clNone
@@ -637,9 +636,9 @@ object DiskDiffsDlg: TDiskDiffsDlg
     AnchorSideLeft.Control = Owner
     AnchorSideBottom.Control = BtnPanel
     Left = 6
-    Height = 22
-    Top = 285
-    Width = 286
+    Height = 19
+    Top = 292
+    Width = 241
     Anchors = [akLeft, akBottom]
     BorderSpacing.Around = 6
     Caption = 'CheckDiskChangesWithLoadingCheckBox'
@@ -647,20 +646,20 @@ object DiskDiffsDlg: TDiskDiffsDlg
   end
   object BtnPanel: TPanel
     Left = 0
-    Height = 41
-    Top = 313
+    Height = 37
+    Top = 317
     Width = 600
     Align = alBottom
     AutoSize = True
     BevelOuter = bvNone
-    ClientHeight = 41
+    ClientHeight = 37
     ClientWidth = 600
     TabOrder = 4
     object RevertAllButton: TButton
-      Left = 484
-      Height = 29
+      Left = 485
+      Height = 25
       Top = 6
-      Width = 110
+      Width = 109
       Align = alRight
       AutoSize = True
       BorderSpacing.Around = 6
@@ -670,10 +669,10 @@ object DiskDiffsDlg: TDiskDiffsDlg
       TabOrder = 0
     end
     object IgnoreDiskChangesButton: TButton
-      Left = 300
-      Height = 29
+      Left = 315
+      Height = 25
       Top = 6
-      Width = 178
+      Width = 164
       Align = alRight
       AutoSize = True
       BorderSpacing.Around = 6
@@ -682,4 +681,9 @@ object DiskDiffsDlg: TDiskDiffsDlg
       TabOrder = 1
     end
   end
+  object SynDiffSyn1: TSynDiffSyn
+    Enabled = False
+    left = 135
+    top = 138
+  end
 end
diff --git a/ide/diskdiffsdialog.pas b/ide/diskdiffsdialog.pas
index 4dfb80f43a..ed1c0e242c 100644
--- a/ide/diskdiffsdialog.pas
+++ b/ide/diskdiffsdialog.pas
@@ -34,7 +34,7 @@ interface
 
 uses
   Classes, SysUtils, LCLProc, Forms, Controls, Buttons, StdCtrls,
-  SynEdit, LCLType, ComCtrls, ExtCtrls,
+  SynEdit, SynHighlighterDiff, LCLType, ComCtrls, ExtCtrls,
   FileProcs, CodeToolManager, CodeCache, Laz_XMLCfg, Laz_XMLWrite,
   Project, DiffPatch, LazarusIDEStrConsts, EnvironmentOpts, EditorOptions,
   PackageDefs;
@@ -59,6 +59,7 @@ type
     RevertAllButton: TButton;
     IgnoreDiskChangesButton: TButton;
     Splitter: TSplitter;
+    SynDiffSyn1: TSynDiffSyn;
     procedure DiskDiffsDlgKeyDown(Sender: TObject; var Key: Word;
           Shift: TShiftState);
     procedure FilesListBoxMouseUp(Sender: TOBject; Button: TMouseButton;