Merging a single cell now throws exception

[mmarton]

This is:

- [x] a bug report
- [ ] a feature request
- [x] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

Merging a single cell does nothing.
I don't know if this is a legal use-case, but it was an undocumented breaking change for me. (I don't do this on purpose, I have a dynamic layout and sometime it happend.)
I already fixed with some if statements, just wanted you to know about this.

What is the current behavior?

Merging a single cell throws an exception. "Merge must be set on a range of cells.;

What are the steps to reproduce?

$sheet->mergeCells('A1:A1');

Please provide a Minimal, Complete, and Verifiable example of code that exhibits the issue without relying on an external Excel file or a web server:

<?php

require __DIR__ . '/vendor/autoload.php';

// Create new Spreadsheet object
$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();

// add code that show the issue here...
$spreadsheet->getActiveSheet()->mergeCells('A1:A1');

What features do you think are causing the issue

• Reader
• Writer
• Styles
• Data Validations
• Formula Calulations
• Charts
• AutoFilter
• Form Elements

Which versions of PhpSpreadsheet and PHP are affected?

latest (1.23.0)

[MarkBaker]

Hmmm! I don't see any change in behaviour between 1.22.0 and 1.23.0

$worksheet->mergeCells('A1:A1');

works in both versions (although it probably shouldn't)

$worksheet->mergeCells('A1');

throws an exception in both versions

[mmarton]

Oh, i oversimplified my example.

my original code on 1.22.0 was:

$sheet->mergeCellsByColumnAndRow(72, 1, 72, 1);

the new one (as ByColumnAndRow was deprecated) on 1.23.0:

$sheet->mergeCells([72, 1, 72, 1]);

the array gets resolved to 'BT1' at vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php:1759 and throws exception at 1785

[MarkBaker]

Ah! That makes things clearer. An unintended breaking change. My apologies.

As you've already fixed it (you could also have used try/catch and done nothing on the catch), I'm inclined to leave it "as is" and see if anybody else raises it. The code should prevent creating a single cell merge range anyway, as it does when a string address was passed in before; it's just that the now-deprecated "byColumnAndRow" method previously allowed the creation of a single cell range.

[morungos]

To confirm, this exact issue broke my code too. This will cause old code to break. It might be sloppy old code, but it is not all that obscure. I have a feeling this will hit a good few people down the line.

[MarkBaker]

@morungos So what would be your suggested approach? Do you think that the restriction should be relaxed to allow something that shouldn't have been permitted in the first place? Or perhaps that it should simply ignore a merge request for a single cell reference? Or are there options that I haven't thought about?

[pmishev]

I just hit the same problem. In my case I was generating a footer row for variable number of columns like:

$worksheet->mergeCellsByColumnAndRow(1, $row, $maxColumn, $row);

Yes, it can be worked around with an if or a try...catch, but it is a bit ugly and one may not even consider that this needs to be specifically handled, until it breaks in production.
In my opinion, the best way to handle this situation is just not do anything, instead of throwing an exception.
I don't think it's really semantically wrong to say you want to merge a cell with itself.