fix(mermaid): Prevent SVGMatrix TypeError on hidden diagrams

[sentry]

DESCRIBE YOUR PR

This PR fixes a TypeError: SVGMatrix.a setter: Value being assigned is not a finite floating-point value that occurred when rendering Mermaid diagrams.

The issue arose because svgPanZoom was being called on all SVG elements, including the hidden (via display:none) dark/light theme clones. These hidden SVGs have zero getBoundingClientRect dimensions. When svgPanZoom attempted to calculate zoom using these zero dimensions, it resulted in non-finite values (Infinity/NaN), which then caused the TypeError when assigned to SVGMatrix.a.

Because this error occurred outside the mermaid.run try/catch block, it aborted the forEach loop prematurely. Consequently, setDoneRendering(true) was never reached, preventing the theme-hiding <style> from being injected and sometimes leaving both light and dark diagrams visible.

The fix moves the svgPanZoom(...) initialization call inside the existing if (rect.width > 0 && rect.height > 0) guard. This ensures that svgPanZoom is only applied to visible SVG elements with valid dimensions, preventing the division-by-zero error and allowing the rendering process to complete correctly.

IS YOUR CHANGE URGENT?

Help us prioritize incoming PRs by letting us know when the change needs to go live.

• Urgent deadline (GA date, etc.):
• Other deadline:
• None: Not urgent, can wait up to 1 week+

SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
• Please give the docs team up to 1 week to review your PR unless you've added an urgent due date to it.
  Thanks in advance for your help!

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

LEGAL BOILERPLATE

Look, I get it. The entity doing business as "Sentry" was incorporated in the State of Delaware in 2015 as Functional Software, Inc. and is gonna need some rights from me in order to utilize my contributions in this here PR. So here's the deal: I retain all rights, title and interest in and to my contributions, and by keeping this boilerplate intact I confirm that Sentry can use, modify, copy, and redistribute my contributions, under Sentry's choice of terms.

EXTRA RESOURCES

• Sentry Docs contributor guide

Fixes DOCS-B3J

_{This PR was automatically generated by Sentry. You can adjust this setting at any time.}

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
develop-docs	Ready	Preview	Aug 22, 2026 10:46pm
sentry-docs	Ready	Preview	Aug 22, 2026 10:46pm