Description:

The incorrect behavior is reproducible if multiple pageviews are tracked with the same pageview id. e.g.

_paq.push(['setPageViewId', 'abcdef']);
_paq.push(['setDocumentTitle', 'view 1']);
_paq.push(['trackPageView']);
_paq.push(['setDocumentTitle', 'view 2']);
_paq.push(['trackPageView']);
_paq.push(['setDocumentTitle', 'view 3']);
_paq.push(['trackPageView']);

fixes #20391

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed