Reader does not return any message when configured with reading inclusive latest messageId

[tomjohn9]

Describe the bug
Creating reader with messageId pointing to MessageId.latest together with startMessageIdInclusive,there is no message returned when readNext is invoked. Newly coming messages are consumed. When using MessageId.earliest, a message is returned - means there are messages in that topic.

Having running local docker image with puslar 2.7.1 and java client 2.7.1

Steps To Reproduce

pulsarClient.newReader(JSONSchema.of(MySchema.class))
                .topic(topic)
                .startMessageId(MessageId.latest)
                .startMessageIdInclusive().create()
                .readNext(250, TimeUnit.MILLISECONDS)

Expected behavior
Last message in queue is returned when calling Reader.readNext with Reader configuration MessageId.latest and startMessageIdInclusive()

Similar Issue
Seems, it was already reported in issue 4912 in first paragraph Test3

Test3:When configuring Reader with startMessageIdInclusive and positioning stream at MessageId.latest, then the next call to Reader.readNext(timeout) should have returned the last message of the topic, but it times out and returns null (without a configured timeout it blocks forever).
.....
Expected behavior
test3 expected to return the last message in topic, test4 hasMessageAvailable expected to be false.

but it is little bit confusing because underlying method readMessage starts with hasMessageAvailable() which in that time returns wrongly true and readNext is reached but no message is returned, but should be.

[PatrykWitkowski]

If you invoke reader.hasMessageAvailable() before reader.readNext() then it works as expected.
It looks like in that case during searching if there're any messages available a message id for the last message is found and the reader pointer is set for it.
Logs:

17:14:42.290 [] [pulsar-client-io-1-1] INFO Get topic last message Id
17:14:42.290 [] [pulsar-client-io-1-1] INFO Successfully getLastMessageId 150:0
17:14:42.293 [] [pulsar-client-io-1-1] INFO Seek subscription to message id 150:0:-1
17:14:42.308 [] [pulsar-client-io-1-1] INFO Successfully reset subscription to message id 150:0:-1

You can use it as a workaround, but still this issue should be fixed.

[adrianog]

Yes it should be fixed anyway. And please can startMessageIdInclusive be made available to c++/python as well. It is a glaring omission. #10328

[codelipenghui]

Here is the discussion thread https://lists.apache.org/thread/kwljdckm0ykstq8oodz6550hqxdltc98 for this issue.