Seen on version 1.21wmf11 (English Wikipedia live).

• On any talk page, use the new section widget.
• In the resulting form, put {{<name>}} (where <name> is the name of any template that contains wiki links) in the subject/headline field.
• Hit show preview.

The template call is partially processed, and the resulting output will appear in the subject/headline preview with clickable links in. Any files present in the template will be rendered as links, with the link text being one of the file parameters.

Wrapping the template call in nowiki tags:

<nowiki>{{<name>}}</nowiki>

results in the template not being processed in the page preview, as expected, but does not affect the subject/headline preview, presumably because the tag has been removed as part of sanitizing HTML content.

Version: 1.21.x
Severity: normal