Message buffers are closed prematurely if you attempt to invoke a command in the host runspace while it is busy

[KirkMunro]

Attempting to invoke a command in the host runspace when it is busy incorrectly results in the message buffers being closed, which prevents further invocations from working properly if they write messages to those buffers.

Steps to reproduce

# Note: This uses the call operator because the commands must all be run in
# one shot to reproduce the issue.
& {
    $ps = [powershell]::Create()
    $ps.Runspace = $host.Runspace
    try {
        $ps.AddScript('Get-Date').Invoke() > $null
    } finally {
        $ps.Dispose()
    }

    [ScriptBlock]::Create({Write-Error 'An error'}).Invoke() > $null
}

Expected behavior

Exception calling "Invoke" with "0" argument(s): "The pipeline was not run because a pipeline is already running. Pipelines cannot be run concurrently."
At line:5 char:9
+         $ps.AddScript('Get-Date').Invoke() > $null
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : PSInvalidOperationException

Actual behavior

Exception calling "Invoke" with "0" argument(s): "The pipeline was not run because a pipeline is already running. Pipelines cannot be run concurrently."
At line:5 char:9
+         $ps.AddScript('Get-Date').Invoke() > $null
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : PSInvalidOperationException

Exception calling "Invoke" with "0" argument(s): "Objects cannot be added to a closed buffer. Make sure the buffer is open for Add and Insert operations to succeed."
At line:10 char:5
+     [ScriptBlock]::Create({Write-Error 'An error'}).Invoke() > $null
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : CmdletInvocationException

Environment data

Name                           Value
----                           -----
PSVersion                      6.2.1
PSEdition                      Core
GitCommitId                    6.2.1
OS                             Microsoft Windows 10.0.17763
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Note: This also repros on PowerShell 5.1, so this is not a new issue.

[Scherlac]

Is this issue related to the following topics:

proxb/PoshRSJob#127

[microsoft-github-policy-service]

This issue has not had any activity in 6 months, if there is no further activity in 7 days, the issue will be closed automatically.

Activity in this case refers only to comments on the issue. If the issue is closed and you are the author, you can re-open the issue using the button below. Please add more information to be considered during retriage. If you are not the author but the issue is impacting you after it has been closed, please submit a new issue with updated details and a link to this issue and the original.

[microsoft-github-policy-service]

This issue has not had any activity in 6 months, if there is no further activity in 7 days, the issue will be closed automatically.

Activity in this case refers only to comments on the issue. If the issue is closed and you are the author, you can re-open the issue using the button below. Please add more information to be considered during retriage. If you are not the author but the issue is impacting you after it has been closed, please submit a new issue with updated details and a link to this issue and the original.