Error on pressing keys Alt+h when trying to get a description of a parameter

[wrtdghvbn-hash]

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues, especially the pinned issues.

Exception report

Oops, something went wrong.
Please report this bug with ALL the details below, including both the 'Environment' and 'Exception' sections.
Please report on GitHub: https://github.com/PowerShell/PSReadLine/issues/new?template=Bug_Report.yaml
Thank you!

### Environment
PSReadLine: 2.3.6+d2e770f93b7a53d8660a6402eb29d1ae1c35e767
PowerShell: 7.5.2
OS: Microsoft Windows 10.0.26100
BufferWidth: 120
BufferHeight: 26

Last 63 Keys:

 l s Spacebar - p a Tab Alt+h q Ctrl+c U P d a t e Backspace Backspace Backspace Backspace Backspace p d a t e - H e l Tab Spacebar - Y Backspace U i Tab Spacebar E Backspace e n - U S Enter
 c p p Spacebar Backspace Backspace Backspace Backspace l s Spacebar - p a Tab Alt+h

### Exception

Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: Cannot perform runtime binding on a null reference
   at CallSite.Target(Closure, CallSite, Object)
   at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0)
   at Microsoft.PowerShell.PSConsoleReadLine.WriteParameterHelp(Object helpContent)
   at Microsoft.PowerShell.PSConsoleReadLine.WriteDynamicHelpContent(String commandName, String parameterName, Boolean isFullHelp)
   at Microsoft.PowerShell.PSConsoleReadLine.DynamicHelpImpl(Boolean isFullHelp)
   at Microsoft.PowerShell.PSConsoleReadLine.ShowParameterHelp(Nullable`1 key, Object arg)
   at Microsoft.PowerShell.PSConsoleReadLine.ProcessOneKey(PSKeyInfo key, Dictionary`2 dispatchTable, Boolean ignoreIfNoAction, Object arg)
   at Microsoft.PowerShell.PSConsoleReadLine.InputLoop()
   at Microsoft.PowerShell.PSConsoleReadLine.ReadLine(Runspace runspace, EngineIntrinsics engineIntrinsics, CancellationToken cancellationToken, Nullable`1 lastRunStatus)

Screenshot

Environment data

PS Version: 7.5.2
PS HostName: ConsoleHost (Windows Terminal)
PSReadLine Version: 2.3.6
PSReadLine EditMode: Windows
OS: 10.0.26100.2308 (WinBuild.160101.0800)
BufferWidth: 156
BufferHeight: 36

Steps to reproduce

Insert any commandlet with parameter, don't press Enter. Press Alt+h to get a hint. The exception occurs both in the terminal and in the console.

Expected behavior

Expecting to receive a short hint on the parameter

Actual behavior

We get an exception

[daxian-dbw]

This is strange and it will be helpful if we can check on the helpContent object that is passed to WriteParameterHelp(Object helpContent).

Can you please run the following script in the same PowerShell session where you can reproduce this issue with Get-ChildItem -LiteralPath and then share the results of the last 3 commands here?

## Get the PSReadLine singleton instance
$t = [Microsoft.PowerShell.PSConsoleReadLine]
$f = $t.GetField('_singleton', [System.Reflection.BindingFlags]::Static -bor [System.Reflection.BindingFlags]::NonPublic)
$instance = $f.GetValue($null)

## Get the method used to retrieve the help content.
$method = $t.GetMethods([System.Reflection.BindingFlags]::Instance -bor [System.Reflection.BindingFlags]::NonPublic) | ? Name -Like *GetDynamicHelpContent

## Call the method with reflection
$v = $method.Invoke($instance, @('Get-ChildItem', 'LiteralPath', $false))

## After running the above, please share the results from those 3 commands.
$v | gm
$null -eq $v.type
$v | fl

[wrtdghvbn-hash]

Good morning. I ran the script several times - before and after installing the help update. When pasting a script, the terminal window once encountered the disappearance of the mouse cursor within the window. But it was not possible to reproduce the problem. Results before "help-update":

PS C:\Users\user> $v | gm
   TypeName: ExtendedCmdletHelpInfo#parameter
   Name             MemberType   Definition
----             ----------   ----------
Equals           Method       bool Equals(System.Object obj)
GetHashCode      Method       int GetHashCode()
GetType          Method       type GetType()
ToString         Method       string ToString()
aliases          NoteProperty string aliases=PSPath, LP
globbing         NoteProperty string globbing=false
isDynamic        NoteProperty string isDynamic=false
name             NoteProperty string name=LiteralPath
parameterSetName NoteProperty string parameterSetName=LiteralItems
parameterValue   NoteProperty System.String parameterValue=string[]
pipelineInput    NoteProperty string pipelineInput=true (ByPropertyName)
position         NoteProperty string position=Named
required         NoteProperty string required=true
type             NoteProperty ExtendedCmdletHelpInfo#type type=@{name=string[]}

PS C:\Users\user> $null -eq $v.type
False
PS C:\Users\user> $v | fl

name             : LiteralPath
required         : true
pipelineInput    : true (ByPropertyName)
isDynamic        : false
globbing         : false
parameterSetName : LiteralItems
parameterValue   : string[]
type             : @{name=string[]}
position         : Named
aliases          : PSPath, LP

[wrtdghvbn-hash]

Results after running "update-help":

PS C:\Users\user> $v | gm

   TypeName: MamlCommandHelpInfo#parameter

Name           MemberType   Definition
----           ----------   ----------
Equals         Method       bool Equals(System.Object obj)
GetHashCode    Method       int GetHashCode()
GetType        Method       type GetType()
ToString       Method       string ToString()
aliases        NoteProperty string aliases=none
description    NoteProperty psobject[] description=System.Management.Automation.PSObject[]
globbing       NoteProperty string globbing=false
name           NoteProperty System.String name=LiteralPath
parameterValue NoteProperty System.String parameterValue=System.String[]
pipelineInput  NoteProperty string pipelineInput=false
position       NoteProperty string position=Named
required       NoteProperty string required=true
variableLength NoteProperty string variableLength=false

PS C:\Users\user> $null -eq $v.type
True
PS C:\Users\user>

PS C:\Users\user> $v | fl

parameterValue : System.String[]
description    : {@{Text=Specifies a path to one or more locations. The value of **LiteralPath** is used exactly as it's
                 typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose
                 it in single quotation marks. Single quotation marks tell PowerShell to not interpret any characters
                 as escape sequences.
                 }, @{Text=For more information, see
                 [about_Quoting_Rules](../Microsoft.PowerShell.Core/About/about_Quoting_Rules.md).}}
name           : LiteralPath
required       : true
variableLength : false
globbing       : false
pipelineInput  : false
position       : Named
aliases        : none

PS C:\Users\user>

[wrtdghvbn-hash]

And one more problem. I don't know if it is related to the current one, but this is what I get in the file ''C:\Users\user\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txt''. Instead of command history, I see this:
PS C:\Users\user> gc 'C:\Users\user\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txt'
楨瑳牯൹⠊敇⵴楆敬慈桳ⴠ汁潧楲桴䡓㉁㘵ⴠ慐桴䐠尺潐敷卲敨汬㜭㔮㈮眭湩砭㐶洮楳⸩慨桳ⴠ煥⠠敇⵴楆敬慈桳ⴠ汁潧楲桴䡓㉁㘵ⴠ慐.
This is a file:

ConsoleHost_history.txt

After deleting this file and reopening the terminal, the newly created history file looks normal.

[mattcargile]

I also get this same stack trace on 7.5.2 and PSReadLine version 2.3.6 with ShowParameterHelp like the below.

filehash -Algorithm # + <Alt+h>

filehash is the "secret" shorthand for Get-FileHash.

Oops, something went wrong.
Please report this bug with ALL the details below, including both the 'Environment' and 'Exception' sections.
Please report on GitHub: https://github.com/PowerShell/PSReadLine/issues/new?template=Bug_Report.yaml
Thank you!

### Environment
PSReadLine: 2.3.6+d2e770f93b7a53d8660a6402eb29d1ae1c35e767
PowerShell: 7.5.2
OS: Microsoft Windows 10.0.22631
BufferWidth: 209
BufferHeight: 51

Last 200 Keys:

 Backspace p s r e a d l i n e o p t i o n Enter
 p s r e a d l i n e k e y h a n d l e r Enter
 UpArrow Spacebar | Spacebar k Backspace ? Spacebar k e y Spacebar - m a Spacebar h Enter
 UpArrow LeftArrow + Enter
 UpArrow LeftArrow LeftArrow LeftArrow RightArrow \ Enter
 l s Spacebar l i p Tab Backspace t Tab Backspace Backspace - l i Backspace Backspace Backspace Backspace Backspace l Backspace Spacebar - l i Tab Alt+h Ctrl+Backspace Ctrl+Backspace Ctrl+Backspace Ctrl+Backspace Ctrl+Backspace g m o Enter
 f d r e s Spacebar p s r e a d l i n e Enter
 f i l e h a s h RightArrow Ctrl+a RightArrow Ctrl+a Backspace g c p Spacebar f i l e h a s h Enter
 UpArrow Ctrl+LeftArrow g e t - Enter
 n i Spacebar t . t x t RightArrow Spacebar | Spacebar f i l e h a s h Spacebar - a Spacebar Alt+h Backspace Backspace a Tab Alt+h Ctrl+a Backspace f i l e h a s h Spacebar - a Tab Alt+h

### Exception

Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: Cannot perform runtime binding on a null reference
   at CallSite.Target(Closure, CallSite, Object)
   at Microsoft.PowerShell.PSConsoleReadLine.WriteParameterHelp(Object helpContent)
   at Microsoft.PowerShell.PSConsoleReadLine.WriteDynamicHelpContent(String commandName, String parameterName, Boolean isFullHelp)
   at Microsoft.PowerShell.PSConsoleReadLine.DynamicHelpImpl(Boolean isFullHelp)
   at Microsoft.PowerShell.PSConsoleReadLine.ShowParameterHelp(Nullable`1 key, Object arg)
   at Microsoft.PowerShell.PSConsoleReadLine.InputLoop()
   at Microsoft.PowerShell.PSConsoleReadLine.ReadLine(Runspace runspace, EngineIntrinsics engineIntrinsics, CancellationToken cancellationToken, Nullable`1 lastRunStatus)

Interestingly, PSReadlineKeyHandler -Chord + <alt+h> returns No help content available. Please use Update-Help to download the latest help content.

Below is the output from Dongbo using Get-FileHash

PS> $v | gm
   TypeName: MamlCommandHelpInfo#parameter

Name           MemberType   Definition
----           ----------   ----------
Equals         Method       bool Equals(System.Object obj)
GetHashCode    Method       int GetHashCode()
GetType        Method       type GetType()
ToString       Method       string ToString()
aliases        NoteProperty string aliases=none
defaultValue   NoteProperty System.String defaultValue=SHA256
description    NoteProperty psobject[] description=System.Management.Automation.PSObject[]
globbing       NoteProperty string globbing=false
name           NoteProperty System.String name=Algorithm
parameterValue NoteProperty System.String parameterValue=System.String
pipelineInput  NoteProperty string pipelineInput=False
position       NoteProperty string position=1
required       NoteProperty string required=false
type           NoteProperty MamlCommandHelpInfo#type type=@{uri=; name=System.String}
variableLength NoteProperty string variableLength=true
PS> $null -eq $v.type
False
PS> $v | fl

name           : Algorithm
defaultValue   : SHA256
type           : @{uri=; name=System.String}
parameterValue : System.String
description    : {@{Text=Specifies the cryptographic hash function to use for computing the hash value of the contents of the specified file or stream. A cryptographic hash function has the property that it is infeasible to find two different files with the same hash value. Hash functions are commonly used with digital signatures and for data integrity. The acceptable values for this parameter are:
                 }, @{Text=- SHA1
                 }, @{Text=- SHA256
                 }, @{Text=- SHA384
                 }…}
required       : false
variableLength : true
globbing       : false
pipelineInput  : False
position       : 1
aliases        : none

Below is the output using FileHash. Notice the TypeName is different and $v.Type is $null.

PS>

   TypeName: HelpInfoShort

Name          MemberType   Definition
----          ----------   ----------
Equals        Method       bool Equals(System.Object obj)
GetHashCode   Method       int GetHashCode()
GetType       Method       type GetType()
ToString      Method       string ToString()
alertSet      NoteProperty MamlCommandHelpInfo#alertSet alertSet=@{alert=System.Management.Automation.PSObject[]}
Category      NoteProperty string Category=Cmdlet
Component     NoteProperty object Component=null
description   NoteProperty psobject[] description=System.Management.Automation.PSObject[]
details       NoteProperty MamlCommandHelpInfo#details details=@{name=Get-FileHash; verb=Get; description=System.Management.Automation.PSObject[]; noun=FileHash}
examples      NoteProperty MamlCommandHelpInfo#examples examples=@{example=System.Management.Automation.PSObject[]}
Functionality NoteProperty object Functionality=null
inputTypes    NoteProperty MamlCommandHelpInfo#inputTypes inputTypes=@{inputType=@{type=@{name=System.String}; description=System.Management.Automation.PSObject[]}}
ModuleName    NoteProperty string ModuleName=Microsoft.PowerShell.Utility
Name          NoteProperty string Name=Get-FileHash
parameters    NoteProperty MamlCommandHelpInfo#parameters parameters=@{parameter=System.Management.Automation.PSObject[]}
PSSnapIn      NoteProperty object PSSnapIn=null
relatedLinks  NoteProperty MamlCommandHelpInfo#relatedLinks relatedLinks=@{navigationLink=System.Management.Automation.PSObject[]}
returnValues  NoteProperty MamlCommandHelpInfo#returnValues returnValues=@{returnValue=@{type=@{name=Microsoft.PowerShell.Utility.FileHash}; description=System.Management.Automation.PSObject[]}}
Role          NoteProperty object Role=null
Synopsis      NoteProperty string Synopsis=Computes the hash value for a file by using a specified hash algorithm.
syntax        NoteProperty MamlCommandHelpInfo#syntax syntax=@{syntaxItem=System.Management.Automation.PSObject[]}
xmlns:command NoteProperty string xmlns:command=http://schemas.microsoft.com/maml/dev/command/2004/10
xmlns:dev     NoteProperty string xmlns:dev=http://schemas.microsoft.com/maml/dev/2004/10
xmlns:maml    NoteProperty string xmlns:maml=http://schemas.microsoft.com/maml/2004/10
xmlns:MSHelp  NoteProperty string xmlns:MSHelp=http://msdn.microsoft.com/mshelp
PS> $null -eq $v.type
True
PS> $v | fl

alertSet      : @{alert=System.Management.Automation.PSObject[]}
inputTypes    : @{inputType=@{type=@{name=System.String}; description=System.Management.Automation.PSObject[]}}
examples      : @{example=System.Management.Automation.PSObject[]}
syntax        : @{syntaxItem=System.Management.Automation.PSObject[]}
returnValues  : @{returnValue=@{type=@{name=Microsoft.PowerShell.Utility.FileHash}; description=System.Management.Automation.PSObject[]}}
details       : @{name=Get-FileHash; verb=Get; description=System.Management.Automation.PSObject[]; noun=FileHash}
parameters    : @{parameter=System.Management.Automation.PSObject[]}
relatedLinks  : @{navigationLink=System.Management.Automation.PSObject[]}
description   : {@{Text=The `Get-FileHash` cmdlet computes the hash value for a file by using a specified hash algorithm. A hash value is a unique value that corresponds to the content of the file. Rather than identifying the contents of a file by its file name, extension, or other designation, a hash assigns a unique value to the contents of a file. File names and extensions can be changed without altering the content of the file, and without changing the hash value. Similarly, the file's content can be changed without changing the name or extension. However, changing even a single character in the contents of a file changes the hash value of the file.
                }, @{Text=The purpose of hash values is to provide a cryptographically-secure way to verify that the contents of a file have not been changed. While some hash algorithms, including MD5 and SHA1, are no longer considered secure against attack, the goal of a secure hash algorithm is to render it impossible to change the contents of a file -- either by accident, or by malicious or unauthorized attempt -- and maintain the same hash value. You can also use hash values to determine if two different files have exactly the same content. If the hash values of two files are identical, the contents of the files are also identical.
                }, @{Text=By default, the `Get-FileHash` cmdlet uses the SHA256 algorithm, although any hash algorithm that is supported by the target operating system can be used.}}
xmlns:maml    : http://schemas.microsoft.com/maml/2004/10
xmlns:command : http://schemas.microsoft.com/maml/dev/command/2004/10
xmlns:dev     : http://schemas.microsoft.com/maml/dev/2004/10
xmlns:MSHelp  : http://msdn.microsoft.com/mshelp
Name          : Get-FileHash
Category      : Cmdlet
Synopsis      : Computes the hash value for a file by using a specified hash algorithm.
Component     : 
Role          : 
Functionality : 
PSSnapIn      : 
ModuleName    : Microsoft.PowerShell.Utility

Using PSReadLineKeyHandler as the cmdlet, has the same output as FileHash. It does not throw the error though. Alias -Name does fail in the same way too.

[daxian-dbw]

Thanks all for the help!
This is a duplicate issue of #4960 and is now fixed with the PR #4971.