ArrayOutput stops response parsing on empty nested arrays

[TheCycoONE]

Bug Report

Current Behavior

When using the redis-cell module v0.2.5 the list of redis commands that Lettuce loads is truncated.

In ReidsCommandFactory.java I put a breakpoint at the return of getCommands - from there I can see that commands contains 137 elements when the redis-cell module is loaded, and 204 when it is not loaded.

In redis-cli I run monitor and see the COMMAND is used to get the list of commands. When I run that with redis-cell loaded I get 205 entries.

Looking at the list of entries I see the 138th entry is

138) 1) "cl.throttle"
     2) (integer) -1
     3) 1) write
     4) (integer) 0
     5) (integer) 0
     6) (integer) 0
     7) (empty array)

For some reason Lettuce stops reading the list of commands at that point.

Expected behavior/code

The full list of 205 commands should be returned. My custom "CL.THROTTLE" lettuce command should work.

Environment

• Lettuce version(s): 5.3.1
• Redis version: 6.0.1
• redis-cell 0.2.5

[TheCycoONE]

I knew this was all working 2 years ago, so I've played with older versions. Downgrading redis to 5.0.8 fixes the issue; so it is a redis 6 specific problem.

[TheCycoONE]

In redis 5.0.8 the command output is slightly different (missing the empty array element).

 30) 1) "cl.throttle"
     2) (integer) -1
     3) 1) write
     4) (integer) 0
     5) (integer) 0
     6) (integer) 0

[mp911de]

Thanks for reporting the issue. The bug is that ArrayOutput doesn't consider nested empty arrays and therefore response processing terminates once the response contains an empty array element.

 69) 1) "hget"
     2) (integer) 3
     3) 1) readonly
        2) fast
     4) (integer) 1
     5) (integer) 1
     6) (integer) 1
     7) 1) @read
        2) @hash
        3) @fast
 70) 1) "cl.throttle"
     2) (integer) -1
     3) 1) write
     4) (integer) 1
     5) (integer) 1
     6) (integer) 1
     7) (empty array)

[mp911de]

That's fixed now in 5.3.2.BUILD-SNAPSHOT. Care to check whether the snapshot build fixes your issue?

[TheCycoONE]

Confirmed working with 5.3.2.BUILD-SNAPSHOT. Thanks!