sequence diagram doesn't render if final edge ends in <br/>

[cdaringe]

Description

When I make a seq diagram, I expect it to render, but it doesn't.

Steps to reproduce

1. Write a sequence diagram
2. use <br/> as the text of the final edge

https://mermaid.live/edit#pako:eNo9jTsOwyAQRK-CtnaUfhUh2coN0kU0G1gblADOGorI8t2DC7ubNx_NCjY7BoSFv5WT5XugSSiapFR_0XpA5cMOQ4Me1e0lVw0dRJZIwbXhuqcGiufIBrBJR_I2YNLWelRLfvySBSxSuQPJdfKAI32WRnV2VI7L050pPXM-ePsDlOM1kg

Screenshots

No response

Code Sample

sequenceDiagram
  A->>B: hi
  B->>A: <br/>

Setup

• Mermaid version: 11.4.0
• Browser and Version: safari

Suggested Solutions

No response

Additional Context

No response

[nour0205]

Sequence Diagram Fails to Render with Multiple <br/> Tags

Hello @cdaringe ,
I tested this issue in the Mermaid Live Editor using Mermaid v11.4.0. However, I could not reproduce the exact issue as originally reported. In my testing, a single <br/> tag renders correctly, and the sequence diagram displays as expected.

However, I found that the issue does occur when using multiple <br/> tags in a row, regardless of whether they appear at the end of the message or elsewhere in the text.

Important Notes
• This issue does not occur when a single <br/> is used.
• The problem is not limited to the last line it occurs whenever two or more <br/> tags appear consecutively in a sequence diagram message.

Environment Details
• Mermaid Version: 11.4.0
• Browser and Version: Microsoft Edge (Version: 132.0.2957.115)

[cdaringe]

Greetings! Clicking the same link I provided above (which is as just as originally described, singular <br />)here it is in chromium & safari:

Thus, while it may not be reproducible on your hardware, it does reliably repo on my box!

MacOS: 15.2 (24C101)
Safari: Version 18.2 (20620.1.16.11.8)
Chromium: Version 134.0.6980.0 (Developer Build) (arm64)

[nour0205]

Hello @cdaringe,

Thank you for the update and for sharing the screenshots. I appreciate the additional details about the issue.
Given that the issue was not reproducible on Microsoft Edge but is consistently occurring on Safari and Chromium on your system, this may likely be a browser-specific rendering issue.

Could you please try running the Mermaid Live Editor in a private/incognito window to check if browser caching affects the result?
Also, do you have any browser extensions enabled that might impact rendering? If so, could you try disabling them temporarily and reloading the editor?
As a workaround, could you also try using \n instead of <br/> to see if the behaviour changes?

I currently don’t have access to Safari on MacOS, but I will test it whenever it’s possible to further verify the behaviour on my end. If I find anything new, I'll update this thread.

Thanks again for your collaboration! 😊