diff --git a/Configuration/GlobalAssemblyInfo.cs b/Configuration/GlobalAssemblyInfo.cs
index 364e5e74d..e64eac230 100644
--- a/Configuration/GlobalAssemblyInfo.cs
+++ b/Configuration/GlobalAssemblyInfo.cs
@@ -15,7 +15,7 @@ internal static class RevisionClass
 	public const string Major = "3";
 	public const string Minor = "4";
 	public const string Build = "2";
-	public const string Revision = "1978";
+	public const string Revision = "1979";
 
         public const string MainVersion = Major + "." + Minor;
 	public const string FullVersion = Major + "." + Minor + "." + Build + "." + Revision;
diff --git a/Configuration/Version.defs b/Configuration/Version.defs
index bb8ff977f..1a9ed47fd 100644
--- a/Configuration/Version.defs
+++ b/Configuration/Version.defs
@@ -1,4 +1,4 @@
-%MINOR%=4
-%REVISION%=1978
 %COREVERSION%=2
+%REVISION%=1979
+%MINOR%=4
 %MAJOR%=3
diff --git a/Localization/DefaultLang.resources b/Localization/DefaultLang.resources
index f0284cd54..86bbba840 100644
Binary files a/Localization/DefaultLang.resources and b/Localization/DefaultLang.resources differ
diff --git a/ReleaseGenerators/PascalABCNET_version.nsh b/ReleaseGenerators/PascalABCNET_version.nsh
index 84254dc63..bc265a836 100644
--- a/ReleaseGenerators/PascalABCNET_version.nsh
+++ b/ReleaseGenerators/PascalABCNET_version.nsh
@@ -1 +1 @@
-!define VERSION '3.4.2.1978'
+!define VERSION '3.4.2.1979'
diff --git a/TestSuite/CompilationSamples/DrawManField.pas b/TestSuite/CompilationSamples/DrawManField.pas
index f3a698a0e..80e727e18 100644
--- a/TestSuite/CompilationSamples/DrawManField.pas
+++ b/TestSuite/CompilationSamples/DrawManField.pas
@@ -587,6 +587,8 @@ end;
 
 procedure buttonStartClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   if t.ThreadState = System.Threading.ThreadState.Suspended then
   begin
     DMField.StepFlag := False;
@@ -604,6 +606,8 @@ end;
 
 procedure buttonStepClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   DMField.StepFlag := True;
   t.Resume;
   (GraphABCControl as Control).Focus;
diff --git a/TestSuite/CompilationSamples/RobotField.pas b/TestSuite/CompilationSamples/RobotField.pas
index 62460fcf5..b13931351 100644
--- a/TestSuite/CompilationSamples/RobotField.pas
+++ b/TestSuite/CompilationSamples/RobotField.pas
@@ -299,12 +299,12 @@ var Sz,Z,Dim: integer;
 begin
   Sz:=CellSize;
   Z:=max(Sz div 12,2);
-  if Sz>64 then Dim:=10
+  {if Sz>64 then Dim:=10
   else if Sz>56 then Dim:=9
   else if Sz>48 then Dim:=8
   else if Sz>40 then Dim:=8
   else if Sz>34 then Dim:=7
-  else if Sz>28 then Dim:=6
+  else} if Sz>28 then Dim:=Round((Sz+20)/8)
   else if Sz>22 then Dim:=5
   else if Sz>12 then Dim:=4
   else Dim:=3;
@@ -316,13 +316,21 @@ begin
 end;
 
 procedure TRobotField.DrawTag(x,y: integer);
-var Sz,sz2: integer;
+var sz2: integer;
 begin
-  Sz:=CellSize;
-  if Sz>80 then sz2:=Sz div 2 - 4
-    else if Sz>52 then sz2:=Sz div 2 - 3
-      else if Sz>12 then sz2:=Sz div 2 - 2
-        else sz2:=Sz div 2 - 1;
+  var Sz:=CellSize;
+  var s2 := Sz div 2;
+  {if Sz>172 then 
+    sz2:=S2 - 6
+  else} if Sz>132 then 
+    sz2:=S2 - 5
+  else if Sz>92 then 
+    sz2:=S2 - 4
+  else if Sz>52 then 
+    sz2:=S2 - 3
+  else if Sz>12 then 
+    sz2:=S2 - 2
+  else sz2:=S2 - 1;
 
   if (RobotX=x) and (RobotY=y)
     then Brush.Color:=clLightGray
@@ -417,10 +425,9 @@ begin
 end;
 
 procedure TRobotField.MoveRobot(x,y: integer);
-var vx,vy: integer;
 begin
-  vx:=RobotX;                                  
-  vy:=RobotY;
+  var vx:=RobotX;                                  
+  var vy:=RobotY;
   RobotX:=x;
   RobotY:=y;
   DrawCell(vx,vy);
@@ -716,6 +723,8 @@ procedure MainWindowClose := SaveIni;
 
 procedure buttonStartClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   if t.ThreadState = System.Threading.ThreadState.Suspended then
   begin
     robField.StepFlag := False;
@@ -733,6 +742,8 @@ end;
 
 procedure buttonStepClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   robField.StepFlag := True;
   t.Resume;
   (GraphABCControl as Control).Focus;
@@ -768,12 +779,11 @@ begin
 end;
 
 procedure CorrectWHLT;
-var mw,mh: integer;
 begin
   if (RobField.DimX=0) or (RobField.DimY=0) then
     exit;
-  mw := (GraphABCControl.Width - 30) div RobField.DimX;
-  mh := (GraphABCControl.Height - 20) div RobField.DimY;
+  var mw := (GraphABCControl.Width - 30) div RobField.DimX;
+  var mh := (GraphABCControl.Height - 20) div RobField.DimY;
   RobField.CellSize := min(mw,mh);
   if RobField.CellSize mod 2 = 1 then 
     RobField.CellSize := RobField.CellSize - 1;
@@ -1106,6 +1116,7 @@ begin
 
   Brush.Color := MainForm.BackColor;
   FillRectangle(0,0,1280,1024);
+  Pen.RoundCap := True;
   
   LoadIni(settings);
   MainForm.Invoke(SetWindowBounds, new System.Drawing.Rectangle(settings.Left,settings.Top,settings.Width,settings.Height));
diff --git a/bin/Lib/DrawManField.pas b/bin/Lib/DrawManField.pas
index f3a698a0e..80e727e18 100644
--- a/bin/Lib/DrawManField.pas
+++ b/bin/Lib/DrawManField.pas
@@ -587,6 +587,8 @@ end;
 
 procedure buttonStartClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   if t.ThreadState = System.Threading.ThreadState.Suspended then
   begin
     DMField.StepFlag := False;
@@ -604,6 +606,8 @@ end;
 
 procedure buttonStepClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   DMField.StepFlag := True;
   t.Resume;
   (GraphABCControl as Control).Focus;
diff --git a/bin/Lib/PABCSystem.pas b/bin/Lib/PABCSystem.pas
index 181f9ea54..a51de029e 100644
--- a/bin/Lib/PABCSystem.pas
+++ b/bin/Lib/PABCSystem.pas
@@ -2283,8 +2283,9 @@ const
   SEEKEOF_FOR_TEXT_WRITEOPENED = 'Функция SeekEof не может быть вызвана для текстового файла, открытого на запись!!SeekEof function can''t be called for file, opened on writing';
   SEEKEOLN_FOR_TEXT_WRITEOPENED = 'Функция SeekEoln не может быть вызвана для текстового файла, открытого на запись!!SeekEoln function can''t be called for file, opened on writing';
   BAD_TYPE_IN_RUNTIMESIZEOF = 'Bad Type in RunTimeSizeOf';
-  PARAMETER_COUNT_MUST_BE_GREATER_0 = 'Параметр count должен быть > 0!!Parameter count must be > 0';
-  PARAMETER_COUNT_MUST_BE_GREATER_1 = 'Параметр count должен быть > 1!!Parameter count must be > 1';
+  PARAMETER_MUST_BE_GREATER_EQUAL_0 = 'Параметр должен быть >= 0!!Parameter must be >= 0';
+  PARAMETER_MUST_BE_GREATER_0 = 'Параметр должен быть > 0!!Parameter must be > 0';
+  PARAMETER_MUST_BE_GREATER_1 = 'Параметр должен быть > 1!!Parameter must be > 1';
   PARAMETER_STEP_MUST_BE_NOT_EQUAL_0 = 'Параметр step не может быть равен 0!!The step parameter must be not equal to 0';
   PARAMETER_STEP_MUST_BE_GREATER_0 = 'Параметр step должен быть > 0!!The step parameter must be not greater than 0';
   PARAMETER_FROM_OUT_OF_RANGE = 'Параметр from за пределами диапазона!!The from parameter out of bounds';
@@ -4105,14 +4106,14 @@ end;
 function SeqGen<T>(count: integer; first: T; next: T->T): sequence of T;
 begin
   if count < 1 then
-    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_COUNT_MUST_BE_GREATER_0));
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_0));
   Result := Iterate(first, next).Take(count);
 end;
 
 function SeqGen<T>(count: integer; first, second: T; next: (T,T) ->T): sequence of T;
 begin
   if count < 1 then
-    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_COUNT_MUST_BE_GREATER_0));
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_0));
   Result := Iterate(first, second, next).Take(count);
 end;
 
@@ -4129,7 +4130,7 @@ end;
 function ArrGen<T>(count: integer; first: T; next: T->T): array of T;
 begin
   if count < 1 then
-    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_COUNT_MUST_BE_GREATER_0));
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_0));
   var a := new T[count];
   a[0] := first;
   for var i := 1 to a.Length - 1 do
@@ -4140,7 +4141,7 @@ end;
 function ArrGen<T>(count: integer; first, second: T; next: (T,T) ->T): array of T;
 begin
   if count < 2 then
-    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_COUNT_MUST_BE_GREATER_1));
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_1));
   var a := new T[count];
   a[0] := first;
   a[1] := second;
@@ -8728,14 +8729,73 @@ end;
 /// Возвращает последние count элементов последовательности
 function TakeLast<T>(Self: sequence of T; count: integer): sequence of T; extensionmethod;
 begin
-  Result := Self.Reverse.Take(count).Reverse;
+  if count < 0 then
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_EQUAL_0));
+  if Self is IList<T> then
+  begin
+    var lst := Self as IList<T>;
+    var ind := lst.Count - count;
+    if ind<0 then ind := 0;
+    for var i:=ind to lst.Count-1 do
+      yield lst[i];
+    exit;  
+  end;
+  
+  var buf := new List<T>;
+  var p := 0;
+  
+  foreach var x in Self do
+    if buf.Count<count then
+      buf.Add(x)
+    else
+    begin
+      buf[p] := x;
+      p := (p+1) mod count;      
+    end;
+  
+  for var i:=0 to buf.Count do
+  begin
+    yield buf[p];    
+    p := (p+1) mod count;      
+  end;  
 end;
 
+{function TakeLast<T>(Self: sequence of T; count: integer): sequence of T; extensionmethod;
+begin
+  Result := Self.Reverse.Take(count).Reverse;
+end;}
+
 /// Возвращает последовательность без последних count элементов 
-function SkipLast<T>(self: sequence of T; count: integer := 1): sequence of T; extensionmethod;
+function SkipLast<T>(Self: sequence of T; count: integer): sequence of T; extensionmethod;
+begin
+  if count < 0 then
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_EQUAL_0));
+  if Self is IList<T> then
+  begin
+    var lst := Self as IList<T>;
+    for var i:=0 to lst.Count - count - 1 do
+      yield lst[i];
+    exit;  
+  end;
+
+  var buf := new List<T>(count);
+  var p := 0;
+  
+  foreach var x in Self do
+    if buf.Count<count then
+      buf.Add(x)
+    else
+    begin
+      yield buf[p];    
+      buf[p] := x;
+      p := (p+1) mod count;      
+    end;
+end;
+
+{function SkipLast<T>(self: sequence of T; count: integer := 1): sequence of T; extensionmethod;
 begin
   Result := Self.Reverse.Skip(count).Reverse;
-end;
+end;}
 
 /// Декартово произведение последовательностей
 function Cartesian<T, T1>(Self: sequence of T; b: sequence of T1): sequence of (T, T1); extensionmethod;
@@ -9302,7 +9362,7 @@ begin
     raise new ArgumentException(GetTranslation(PARAMETER_STEP_MUST_BE_NOT_EQUAL_0));
   
   if count < 0 then
-    raise new ArgumentException(GetTranslation(PARAMETER_COUNT_MUST_BE_GREATER_0));
+    raise new System.ArgumentOutOfRangeException('count', count, GetTranslation(PARAMETER_MUST_BE_GREATER_EQUAL_0));
   
   if (from < 0) or (from > Len - 1) then
     raise new ArgumentException(GetTranslation(PARAMETER_FROM_OUT_OF_RANGE));
diff --git a/bin/Lib/RobotField.pas b/bin/Lib/RobotField.pas
index 0fc56b44d..b13931351 100644
--- a/bin/Lib/RobotField.pas
+++ b/bin/Lib/RobotField.pas
@@ -723,6 +723,8 @@ procedure MainWindowClose := SaveIni;
 
 procedure buttonStartClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   if t.ThreadState = System.Threading.ThreadState.Suspended then
   begin
     robField.StepFlag := False;
@@ -740,6 +742,8 @@ end;
 
 procedure buttonStepClick(o: Object; e: EventArgs);
 begin
+  if t=nil then 
+    exit;
   robField.StepFlag := True;
   t.Resume;
   (GraphABCControl as Control).Focus;