The [gelf payload specification](http://docs.graylog.org/en/2.4/pages/gelf.html#gelf-payload-specification)
demands that the field `short_message` *MUST* be set by the client library.
Since docker logging via the gelf driver sends messages line by line, it can happen that messages with an empty
`short_message` are passed on. This causes strict downstream processors (like graylog) to raise an exception.
The logger now skips messages with an empty line.
Resolves: #40232
See also: #37572
Signed-off-by: Jonas Heinrich <Jonas@JonasHeinrich.com>
(cherry picked from commit 5c6b913ff1)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
449b60fcd0