Render and fill the template with automatic handling of cell merging functionality 渲染填充模板自动处理单元格合并功能

[wangmiscoding]

Resolve the issue where newly added rows do not inherit the original row's merge information during template filling:

1. Only effective when direction=VERTICAL in FillConfig.
2. Only effective when autoStyle=true in FillConfig.
3. Only effective when forceNewRow=true in FillConfig.
4. Only effective when the merge region of the original row does not span across columns.

[wangmiscoding]

#378

[wangmiscoding]

效果：

[Copilot]

Pull Request Overview

This pull request implements automatic handling of cell merging when filling Excel templates, ensuring that newly added rows inherit merge information under specific FillConfig settings. Key changes include:

• Addition of a new test case in TemplateMergeTest to validate the merge functionality.
• Modifications in ExcelWriteFillExecutor to capture original row merged region information and apply these merges to newly added rows.
• Updates to record and propagate cell styles and merged regions when creating new cells in vertical fill mode with forceNewRow and autoStyle enabled.

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
fastexcel-test/src/test/java/cn/idev/excel/test/core/template/TemplateMergeTest.java	Adds a new test ensuring that fill processing properly handles merged cell regions.
fastexcel-core/src/main/java/cn/idev/excel/write/executor/ExcelWriteFillExecutor.java	Implements logic to record merged regions in the original row and apply them to new rows.

Comments suppressed due to low confidence (1)

fastexcel-core/src/main/java/cn/idev/excel/write/executor/ExcelWriteFillExecutor.java:77

• [nitpick] Consider renaming 'originalMergeRegionMap' to 'initialRowMergeRegions' to more clearly indicate that it holds merged region information from the initial row.

    private final Map<AnalysisCell,List<CellRangeAddress>> originalMergeRegionMap = MapUtils.newHashMap();

[Copilot]

Ensure that the loop range based on 'collectionData.size()' is valid and that the new merged region does not exceed the sheet's boundaries, as using 'addMergedRegionUnsafe' without boundary checks may lead to runtime exceptions.

Suggested change

	for (CellRangeAddress cellAddresses : regionList) {
	cachedSheet.addMergedRegionUnsafe(new CellRangeAddress(index, index, cellAddresses.getFirstColumn(), cellAddresses.getLastColumn()));
	if (index < 0 || index >= cachedSheet.getWorkbook().getSpreadsheetVersion().getMaxRows()) {
	continue; // Skip if the row index is out of bounds
	}
	for (CellRangeAddress cellAddresses : regionList) {
	int firstColumn = cellAddresses.getFirstColumn();
	int lastColumn = cellAddresses.getLastColumn();
	if (firstColumn < 0 || lastColumn >= cachedSheet.getWorkbook().getSpreadsheetVersion().getMaxColumns()) {
	continue; // Skip if the column range is out of bounds
	}
	cachedSheet.addMergedRegionUnsafe(new CellRangeAddress(index, index, firstColumn, lastColumn));