From cfcb832434e02c935a58c6708b80b0b522d24263 Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Tue, 10 Jun 2025 14:24:20 +0000
Subject: [PATCH] fpspreadsheet: Make chart skip blank cells in xlsx (instead
 of drawing them as zero).

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9776 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 components/fpspreadsheet/source/common/fpsexprparser.pas  | 4 +++-
 components/fpspreadsheet/source/common/xlsxooxmlchart.pas | 8 +++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/components/fpspreadsheet/source/common/fpsexprparser.pas b/components/fpspreadsheet/source/common/fpsexprparser.pas
index 475e5c9e4..6944543ac 100644
--- a/components/fpspreadsheet/source/common/fpsexprparser.pas
+++ b/components/fpspreadsheet/source/common/fpsexprparser.pas
@@ -4573,7 +4573,8 @@ end;
 
 { Is called when a formula is moved from the ASrcCell to ADestCell. Must
   adjust cell references which originally were relative to ASrcCell such that
-  they are relative to ADestCell afterwards. }
+  they are relative to ADestCell afterwards.
+  No need to move the worksheet because it is always an absolute reference. }
 procedure TsCellExprNode.MoveCells(ASourceCell, ADestCell: PCell);
 var
   delta: Int64;
@@ -4589,6 +4590,7 @@ begin
     delta := Int64(ADestCell^.Col) - Int64(ASourceCell^.Col);
     FCol := Int64(FCol) + delta;
   end;
+
 end;
 
 function TsCellExprNode.NodeType: TsResultType;
diff --git a/components/fpspreadsheet/source/common/xlsxooxmlchart.pas b/components/fpspreadsheet/source/common/xlsxooxmlchart.pas
index 327e43b00..3264a14b1 100644
--- a/components/fpspreadsheet/source/common/xlsxooxmlchart.pas
+++ b/components/fpspreadsheet/source/common/xlsxooxmlchart.pas
@@ -2808,6 +2808,8 @@ var
   chart: TsChart;
   indent: String;
   savedRotatedAxes: Boolean;
+  plotVisOnly: String;
+  dispBlanksAs: String;
 begin
   indent := DupeString(' ', AIndent);
   chart := TsWorkbook(Writer.Workbook).GetChartByIndex(AChartIndex);
@@ -2828,8 +2830,12 @@ begin
   WriteChartPlotAreaNode(AStream, AIndent + 2, chart);
   WriteChartLegendNode(AStream, AIndent + 2, chart.Legend);
 
+  plotVisOnly  := indent + '  <c:plotVisOnly val="1" />' + LE;
+  dispBlanksAs := indent + '  <c:dispBlanksAs val="gap" />' + LE;      // empty cells are not plotted
+
   AppendToStream(AStream,
-    indent + '  <c:plotVisOnly val="1" />' + LE +
+    plotVisOnly +
+    dispBlanksAs +
     indent + '</c:chart>' + LE
   );