gdbusmessage: Gracefully handle message signatures with invalid types
With the changes to limit GVariant type nesting (commit 7c4e6e9f), it’s now possible to have a valid type signature which is not a valid GVariant type when enclosed in parentheses (to make it a tuple).
Check for that when parsing the signature field in a D-Bus message.
oss-fuzz#11120
Signed-off-by: Philip Withnall withnall@endlessm.com
Edited by Philip Withnall