From dfa57b80e92ded06965575a20de91df70f2dcdf5 Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Mon, 20 May 2019 10:13:39 +0000
Subject: [PATCH] fpspreadsheet: Fix infinite loop in Worksheeet sorting when
 the sorted range contains an empty cell. Make Worksheetgrid.Sort public.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6928 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 components/fpspreadsheet/source/common/fpspreadsheet.pas   | 7 +++++++
 .../fpspreadsheet/source/visual/fpspreadsheetgrid.pas      | 4 +++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/components/fpspreadsheet/source/common/fpspreadsheet.pas b/components/fpspreadsheet/source/common/fpspreadsheet.pas
index 241307b34..584e9193c 100644
--- a/components/fpspreadsheet/source/common/fpspreadsheet.pas
+++ b/components/fpspreadsheet/source/common/fpspreadsheet.pas
@@ -4339,6 +4339,11 @@ begin
     if (ACell1 = nil) and (ACell2 = nil) then
       Result := 0
     else
+    if (ACell1 <> nil) and (ACell1^.ContentType = cctEmpty) and
+       (ACell2 <> nil) and (ACell2^.ContentType = cctEmpty)
+    then
+      Result := 0
+    else
     if (ACell1 = nil) or (ACell1^.ContentType = cctEmpty) then
     begin
       Result := +1;   // Empty cells go to the end
@@ -4349,9 +4354,11 @@ begin
       Result := -1;   // Empty cells go to the end
       exit;           // Avoid SortOrder to bring the empty cell to the top!
     end else
+    {
     if (ACell1^.ContentType = cctEmpty) and (ACell2^.ContentType = cctEmpty) then
       Result := 0
     else
+    }
     if (ACell1^.ContentType = cctUTF8String) and (ACell2^.ContentType = cctUTF8String) then
     begin
       if ssoCaseInsensitive in ASortOptions then
diff --git a/components/fpspreadsheet/source/visual/fpspreadsheetgrid.pas b/components/fpspreadsheet/source/visual/fpspreadsheetgrid.pas
index ff66110ab..24a129a3a 100644
--- a/components/fpspreadsheet/source/visual/fpspreadsheetgrid.pas
+++ b/components/fpspreadsheet/source/visual/fpspreadsheetgrid.pas
@@ -324,7 +324,6 @@ type
     function  SelectCell(ACol, ARow: Integer): Boolean; override;
     procedure SetEditText(ACol, ARow: Longint; const AValue: string); override;
     procedure Setup;
-    procedure Sort(AColSorting: Boolean; AIndex, AIndxFrom, AIndxTo:Integer); override;
     function ToPixels(AValue: Double): Integer;
     procedure TopLeftChanged; override;
     function TrimToCell(ACell: PCell): String;
@@ -435,6 +434,8 @@ type
       const ALeftOuterStyle, ATopOuterStyle, ARightOuterStyle, ABottomOuterStyle,
       AHorInnerStyle, AVertInnerStyle: TsCellBorderStyle);
 
+    procedure Sort(AColSorting: Boolean; AIndex, AIndxFrom, AIndxTo:Integer); override;
+
     { Row height / col width calculation }
     procedure UpdateColWidth(ACol: Integer);
     procedure UpdateColWidths(AStartIndex: Integer = 0);
@@ -5569,6 +5570,7 @@ begin
     );
 end;
 
+
 {@@ ----------------------------------------------------------------------------
   Converts a coordinate given in workbook units to pixels using the current
   screen resolution