Introducing rewrite_tag breaks multiline in 1.8.7+ - repro

custom_parsers-repro.conf

[MULTILINE_PARSER]
    name          multiline_dotnet_console
    type          regex
    #
    # Regex rules for multiline parsing
    # ---------------------------------
    #
    # configuration hints:
    #
    #  - first state always has the name: start_state
    #  - every field in the rule must be inside double quotes
    #
    # rules |   state name  | regex pattern                  | next state
    # ------|---------------|--------------------------------------------
    rule      "start_state"   "/^info:/"                       "cont"
    rule      "cont"          "/^\s{4,}/"                      "cont"

fluent-bit-repro-norewrite.conf

[SERVICE]
    Daemon Off
    Flush 1
    Log_Level debug
    Parsers_File custom_parsers-repro.conf
    HTTP_Server Off
    HTTP_Listen 0.0.0.0
    HTTP_Port 2020
    Health_Check Off

[INPUT]
    Name tail
    Path ./repro-external-api-745f757c59-ndgg8_staging_repro-external-api-4303caf1c98782551d123e21f7ea93b56f87b3c59c27e1d325cb126abf6eda6d.log
    multiline.parser docker, cri
    Tag kube.*
    Mem_Buf_Limit 5MB
    Skip_Long_Lines On
    Refresh_Interval 5
    Read_from_Head true

[FILTER]
    Name kubernetes
    Match kube.*
    Merge_Log On
    Keep_Log Off
    K8S-Logging.Parser On
    K8S-Logging.Exclude On
    use_tag_for_meta on

[FILTER]
    name                  multiline
    match                 kube.*
    multiline.key_content log
    multiline.parser      multiline_dotnet_console

[OUTPUT]
    Name stdout
    Match *

fluent-bit-repro-rewrite.conf

[SERVICE]
    Daemon Off
    Flush 1
    Log_Level debug
    Parsers_File custom_parsers-repro.conf
    HTTP_Server Off
    HTTP_Listen 0.0.0.0
    HTTP_Port 2020
    Health_Check Off

[INPUT]
    Name tail
    Path ./repro-external-api-745f757c59-ndgg8_staging_repro-external-api-4303caf1c98782551d123e21f7ea93b56f87b3c59c27e1d325cb126abf6eda6d.log
    multiline.parser docker, cri
    Tag kube.*
    Mem_Buf_Limit 5MB
    Skip_Long_Lines On
    Refresh_Interval 5
    Read_from_Head true

[FILTER]
    Name kubernetes
    Match kube.*
    Merge_Log On
    Keep_Log Off
    K8S-Logging.Parser On
    K8S-Logging.Exclude On
    use_tag_for_meta on

[FILTER]
    Name          rewrite_tag
    Match         kube.*
    Rule          $kubernetes['namespace_name'] ^(staging|production)$ apps false
    Emitter_Name  apps_tag_rewriter

[FILTER]
    name                  multiline
    match                 apps
    multiline.key_content log
    multiline.parser      multiline_dotnet_console

[OUTPUT]
    Name stdout
    Match *

repro-external-api-745f757c59-ndgg8_staging_repro-external-api-4303caf1c98782551d123e21f7ea93b56f87b3c59c27e1d325cb126abf6eda6d.log

{"log":"info: Microsoft.AspNetCore.Hosting.Diagnostics[2]\n","stream":"stdout","time":"2021-11-10T15:39:34.790353236Z"}
{"log":"      =\u003e SpanId:01505dc18911774c, TraceId:b86129629f6999479b90a26bae122e46, ParentId:0000000000000000 =\u003e ConnectionId:0HMD3I6TBKKDA =\u003e RequestPath:/ RequestId:0HMD3I6TBKKDA:00000002\n","stream":"stdout","time":"2021-11-10T15:39:34.79036159Z"}
{"log":"      Request finished HTTP/1.1 GET http://10.0.2.125:80/ - - - 200 - text/plain;+charset=utf-8 0.1316ms\n","stream":"stdout","time":"2021-11-10T15:39:34.790376879Z"}
{"log":"info: Microsoft.AspNetCore.Hosting.Diagnostics[1]\n","stream":"stdout","time":"2021-11-10T15:39:44.788911426Z"}
{"log":"      =\u003e SpanId:0418144220ef6845, TraceId:cfe54fe94ecaaa44ab09457f7f868752, ParentId:0000000000000000 =\u003e ConnectionId:0HMD3I6TBKKDC =\u003e RequestPath:/ RequestId:0HMD3I6TBKKDC:00000002\n","stream":"stdout","time":"2021-11-10T15:39:44.789284381Z"}
{"log":"      Request starting HTTP/1.1 GET http://10.0.2.125:80/ - -\n","stream":"stdout","time":"2021-11-10T15:39:44.789428947Z"}
{"log":"info: Microsoft.AspNetCore.Hosting.Diagnostics[2]\n","stream":"stdout","time":"2021-11-10T15:39:44.789629801Z"}
{"log":"      =\u003e SpanId:0418144220ef6845, TraceId:cfe54fe94ecaaa44ab09457f7f868752, ParentId:0000000000000000 =\u003e ConnectionId:0HMD3I6TBKKDC =\u003e RequestPath:/ RequestId:0HMD3I6TBKKDC:00000002\n","stream":"stdout","time":"2021-11-10T15:39:44.789646104Z"}
{"log":"      Request finished HTTP/1.1 GET http://10.0.2.125:80/ - - - 200 - text/plain;+charset=utf-8 0.1946ms\n","stream":"stdout","time":"2021-11-10T15:39:44.789651707Z"}
{"log":"info: Microsoft.AspNetCore.Hosting.Diagnostics[1]\n","stream":"stdout","time":"2021-11-10T15:39:44.789656241Z"}
{"log":"      =\u003e SpanId:5018968b4ab3f342, TraceId:94b3b5b666fba84ca420f0a336559e7b, ParentId:0000000000000000 =\u003e ConnectionId:0HMD3I6TBKKDD =\u003e RequestPath:/ RequestId:0HMD3I6TBKKDD:00000002\n","stream":"stdout","time":"2021-11-10T15:39:44.789660238Z"}
{"log":"      Request starting HTTP/1.1 GET http://10.0.2.125:80/ - -\n","stream":"stdout","time":"2021-11-10T15:39:44.789664262Z"}
{"log":"info: Microsoft.AspNetCore.Hosting.Diagnostics[2]\n","stream":"stdout","time":"2021-11-10T15:39:44.789667968Z"}
{"log":"      =\u003e SpanId:5018968b4ab3f342, TraceId:94b3b5b666fba84ca420f0a336559e7b, ParentId:0000000000000000 =\u003e ConnectionId:0HMD3I6TBKKDD =\u003e RequestPath:/ RequestId:0HMD3I6TBKKDD:00000002\n","stream":"stdout","time":"2021-11-10T15:39:44.789671454Z"}
{"log":"      Request finished HTTP/1.1 GET http://10.0.2.125:80/ - - - 200 - text/plain;+charset=utf-8 0.1048ms\n","stream":"stdout","time":"2021-11-10T15:39:44.789675595Z"}