exception on loading : An item with the same key has already been added.

[thenik]

Hello
Got some issue with the next file:

optax_price_xiaomi_obnov_1707 (2).xlsx

any way how to "try catch" such an error and to read this file till the end?

[tonyqus]

which version of NPOI are you using?

And please show me the code to reproduce the issue.

[thenik]

I used 2.5.6

but I tested with 2.6.1
it has the same Error

[tonyqus]

Can you share the code to reproduce the issue?

[karakasa]

Can you share the code to reproduce the issue?

A simple loading file will raise the exception.

const string path = @"d:\whatever\optax_price_xiaomi_obnov_1707.2.xlsx";
var wb = new XSSFWorkbook(path);

As for the file, there're duplicated entries in xl/drawings/_rels/drawing1.xml.rels referencing the same file.

<Relationship Id="rId4" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image" Target="../media/image4.jpeg"/>
...
<Relationship Id="rId91" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image" Target="../media/image4.jpeg"/>

I think it's because of image reuse (i.e. copy & paste inside Excel) as put in the cell of E10 & E133.

I implemented a quick fix in NPOI.OpenXml4Net.Core/OPC/PackageRelationshipCollection.cs, did a round-trip test and witnessed no side effects so far. Maybe someone, who is more familar with OOXML, can explain if anything different is gonna happen.

https://github.com/nissl-lab/npoi/blob/fd8103d1eeae6483f941073d10f09303bbfb57df/openxml4Net/OPC/PackageRelationshipCollection.cs#L249C8-L249C8

        if (targetMode == TargetMode.Internal)
        {
            var uriOriginalString = targetUri.OriginalString;

            if (!internalRelationshipsByTargetName.ContainsKey(uriOriginalString))
            {
                internalRelationshipsByTargetName.Add(uriOriginalString, rel);
            }
        }

p.s. I understand ContainsKey+Add is suboptimal to this[key] performance-wise but I don't know if it's better to keep the first rel or the last rel, while lower dotnet targets don't have a TryAdd extension.

[tonyqus]

I notice this file is generated by LibreOffice. I resave the file with Microsoft Office and I don't see a duplicate key anymore

Here is the drawing1.xml.rels from the MIcrosoft Office resaved file.
drawing1.xml.rels.txt

In this case, I don't think it is a bug. The file provided is not well-generated.

[thenik]

This file I get for a supplier via loading from a website url.
I cannot open it and resave if in Microsoft Office as you suggested.
From my point of view is a bug because I can open this file in Microsoft Office and there is no any exception
but when I open file via c# code using NPOI it calls exception, so it is a bug.

[karakasa]

I suppose that NPOI should have a policy on whether to fix issues relating to malformed but Excel-readable files. The answer is probably yes.

[tonyqus]

Fair enough. I'll fix this issue and see if we can suppress the exception without breaking anything

[thenik]

wow, many thanks! you are the best!