Duplicate edges pasted at random places

[Tomas-Bueno-Momcilovic]

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• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

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Describe the bug

Duplicate edges (i.e., arrows) get created in seemingly random places in the diagram. As far as I can notice, these are duplicates of edges I copy-pasted to use elsewhere, which get re-pasted somewhere else with a delay. This only applies to edges. I am confident I haven't accidentally pasted two times.

To Reproduce
Steps to reproduce the behavior:

1. Create an edge between two nodes.
2. Copy-paste the edge elsewhere (e.g., to attach to additional two nodes).
3. Repeat until the duplicates occur.

Or:

1. Create an example diagram with nodes and edges.
2. Save it and close the app.
3. Open the diagram in the app again.
4. Repeat until duplicates are scattered across the canvas.

Expected behavior
Only single copy-pasted edge, and not additional duplicate edges.

Screenshots

draw.io version (In the Help->About menu of the draw.io editor):

• draw.io version 29.6.6

Desktop (please complete the following information):

• OS: Windows

Additional context
Nothing I can think of. Would be happy to provide additional things if needed.

[draw-io-triage-bot]

👋 Thank you for opening this issue!

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Summary: The user reports that when copy-pasting edges (arrows) between nodes in draw.io desktop v29.6.6 on Windows, duplicate edges appear at seemingly random locations on the canvas, either shortly after pasting or after saving and reopening the diagram.

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📝 Additional Information Needed

To help us investigate this more effectively, could you please provide:

• Sample diagram file: A .drawio file that exhibits the issue (or one where the issue can be reliably reproduced) would greatly help developers debug this. The screenshot is helpful but an actual file would allow inspection of the XML for anomalies.
• Storage backend: Is the file saved locally, on Google Drive, OneDrive, or another cloud storage? This could matter if the issue involves save/reload cycles.
• Reproducibility details: The two reproduction paths suggest the issue is intermittent. How frequently does this occur — every time, or only occasionally? Does it happen immediately after paste, or only after saving and reopening?
• Clipboard method: Are you using Ctrl+C / Ctrl+V, right-click context menu, or the Edit menu to copy-paste? This can matter for edge-specific clipboard handling.

We also have some questions:

• Can you share the .drawio XML file (or a minimal version of it) where duplicate edges appear? This would let developers inspect whether the duplicates exist in the saved XML or are rendered at open time.
• When you say the duplicates appear 'with a delay' — do you mean they appear seconds after pasting, or do they appear only after saving and reopening the file?
• Are the duplicate edges connected to any nodes, or are they floating/unattached? In the screenshot, can you identify which edges are the originals and which are the duplicates?
• Does this happen with a brand new, simple diagram (e.g., just 2 nodes and 1 edge, copy-paste once), or only in larger/more complex diagrams?
• Where is the file stored — locally on disk, or via a cloud integration (Google Drive, OneDrive, etc.)?

📋 Bug Report Template

**Environment:**
- draw.io version: [e.g., web app / desktop 24.x.x / Confluence plugin]
- Browser (if web): [e.g., Chrome 120, Firefox 121]
- OS: [e.g., Windows 11, macOS 14, Ubuntu 22.04]

**Steps to Reproduce:**
1. Go to ...
2. Click on ...
3. See error

**Expected Behavior:**
What you expected to happen.

**Actual Behavior:**
What actually happened.

**Screenshots/Files:**
If applicable, add screenshots or attach the .drawio file.

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_{🤖 This is an automated response to help with initial triage. A human maintainer will review this issue. If you've provided all the requested information, no further action is needed - we'll get back to you soon!}

[Tomas-Bueno-Momcilovic]

• Sample diagram file: I don't keep these extra edges in my working diagrams. Unfortunately, I'm unable to reliably reproduce the issue in a separate file. It is very likely a OneDrive merging conflict issue, which is known to happen in other apps (e.g., SumatraPDF, see linked issue).
• Storage backend: OneDrive with local sync enabled.
• Reproducibility details: Not very frequently, but often enough to be noticeable (every ~10 copy-paste). It's not a blocking issue, but annoying nonetheless.
• Clipboard method: Almost exclusively Ctrl+C --> Ctrl+V.

Questions:

• No, sorry. When I manage to reproduce the issue, I will extract and share.
• Both. Please see description above.
• Floating/unattached only.
• Unclear, but currently larger/more complex diagrams.
• Answered above.

Note to human maintainers: Consider adding to the system prompt of your Triage Bot to not repeat questions or addressed points.

[Tomas-Bueno-Momcilovic]

Another example, after opening the diagram: