95 nullreferenceexception with rows fit (#254)

* Fixed a performance issue caused by a large number of merged ranges.  (#246 Three lists generation on one sheet hangs)

* fix issue #95 (nullreferenceexception with RowsFit|ColsFit tag when empty data source)

Author: b0bi79

ClosedXML.Report/Options/ColsFitTag.cs

@@ -27,18 +27,28 @@ public override void Execute(ProcessingContext context)
             // worksheet column
             else if (cellRow == 1)
             {
-                ws.Column(cellClmn).AdjustToContents(ws.FirstRowUsed().RowNumber(), ws.LastRowUsed().RowNumber());
+                var firstRowUsed = ws.FirstRowUsed();
+                if (firstRowUsed != null)
+                    ws.Column(cellClmn).AdjustToContents(firstRowUsed.RowNumber(), ws.LastRowUsed().RowNumber());
             }
             // whole range
             else if (IsSpecialRangeCell(xlCell))
             {
-                ws.Columns(xlRange.FirstColumnUsed().ColumnNumber(), xlRange.LastColumnUsed().ColumnNumber())
-                    .AdjustToContents(xlRange.FirstRowUsed().RowNumber()-1, xlRange.LastRowUsed().RowNumber());
+                var firstUsed = xlRange.FirstCellUsed();
+                var lastUsed = xlRange.LastCellUsed();
+
+                if (firstUsed != null && lastUsed != null)
+                {
+                    ws.Columns(firstUsed.WorksheetColumn().ColumnNumber(), lastUsed.WorksheetColumn().ColumnNumber())
+                        .AdjustToContents(firstUsed.WorksheetRow().RowNumber() - 1, lastUsed.WorksheetRow().RowNumber());
+                }
             }
             // range column
             else if (IsSpecialRangeRow(xlCell))
             {
-                ws.Column(cellClmn).AdjustToContents(xlRange.FirstRowUsed().RowNumber(), xlRange.LastRowUsed().RowNumber());
+                var firstRowUsed = xlRange.FirstRowUsed();
+                if (firstRowUsed != null)
+                    ws.Column(cellClmn).AdjustToContents(firstRowUsed.RowNumber(), xlRange.LastRowUsed().RowNumber());
             }
             // only one cell
             else

ClosedXML.Report/Options/RowsFitTag.cs

@@ -4,7 +4,8 @@ public class RowsFitTag : OptionTag
     {
         public override void Execute(ProcessingContext context)
         {
-            var xlCell = Cell.GetXlCell(context.Range);
+            var xlRange = context.Range;
+            var xlCell = Cell.GetXlCell(xlRange);
             var cellAddr = xlCell.Address.ToStringRelative(false);
             var cellRow = xlCell.WorksheetRow().RowNumber();
             var cellClmn = xlCell.WorksheetColumn().ColumnNumber();
@@ -26,18 +27,28 @@ public override void Execute(ProcessingContext context)
             // worksheet row
             else if (cellClmn == 1)
             {
-                ws.Rows(cellRow, cellRow).AdjustToContents(ws.FirstColumnUsed().ColumnNumber(), ws.LastColumnUsed().ColumnNumber());
+                var firstColumnUsed = ws.FirstColumnUsed();
+                if (firstColumnUsed != null)
+                    ws.Rows(cellRow, cellRow).AdjustToContents(firstColumnUsed.ColumnNumber(), ws.LastColumnUsed().ColumnNumber());
             }
             // whole range
             else if (IsSpecialRangeCell(xlCell))
             {
-                ws.Rows(context.Range.FirstRowUsed().RowNumber(), context.Range.LastRowUsed().RowNumber())
-                    .AdjustToContents(context.Range.FirstColumnUsed().ColumnNumber(), context.Range.LastColumnUsed().ColumnNumber());
+                var firstUsed = xlRange.FirstCellUsed();
+                var lastUsed = xlRange.LastCellUsed();
+
+                if (firstUsed != null && lastUsed != null)
+                {
+                    ws.Rows(firstUsed.WorksheetRow().RowNumber(), lastUsed.WorksheetRow().RowNumber())
+                        .AdjustToContents(firstUsed.WorksheetColumn().ColumnNumber(), lastUsed.WorksheetColumn().ColumnNumber());
+                }
             }
             // range row
-            if (cellClmn == context.Range.RangeAddress.FirstAddress.ColumnNumber)
+            if (cellClmn == xlRange.RangeAddress.FirstAddress.ColumnNumber)
             {
-                ws.Rows(cellRow, cellRow).AdjustToContents(context.Range.FirstColumnUsed().ColumnNumber(), context.Range.LastColumnUsed().ColumnNumber());
+                var firstColumnUsed = xlRange.FirstColumnUsed();
+                if (firstColumnUsed != null)
+                    ws.Rows(cellRow, cellRow).AdjustToContents(firstColumnUsed.ColumnNumber(), xlRange.LastColumnUsed().ColumnNumber());
             }
             // only one cell
             else