Given
There is a file variable with file name "naïve with umläut.txt" stored with a process instance.

When
I request the variable via REST API GET /process-instance/{id}/variables/{varName}/data.

Then
The content disposition header in the response contains filename=naïve with umläut.txt which includes non-ASCII characters as well as whitespaces and does therefore not respect RFC6266.
This can break receivers of this response as they might not be able to handle whitespaces and non-ASCII characters.

Expected
The header contains filename="naïve with umläut.txt"; filename*=utf-8''na%C3%AFve%20with%20uml%C3%A4ut.txt.