It's allowed in values, but not in parameter names. The moment
a parameter name contains an `=` the parameter name will be cut
off at this point, and what's behind the `=` will become part
of the value.
You can test this on any live wiki. Open VisualEditor. Edit any
template. Add a parameter with a name like `a=` and some value.
Switch to wikitext mode and back. Edit the template. The `=` is
now part of the value.
Bug: T98065
Change-Id: I5e00e8fac987471243605816b041d3638927ac3b
When what you type is a partial match, you can't add it as an
unknown parameter, even if that would be the correct action. The
reason for this unexpected edge-case is a mistake in the code
where a variable called "exactMatch" is set when a *partial*
"nameMatch" was found.
Bug: T285940
Change-Id: I6d12e2d7251a19d7d5f8be544c3c32a3ac14fcf0
