Passing empty strings using double quotes via PowerShell.exe -command - powershell

Question

Seems like a bug... Only thing I can think of is double quotes are being lost through external invocation but it works when the string has a character, so I don't think so. Zero length string fails.
My version:
>$host
Name : ConsoleHost
Version : 3.0
Empty string fails:
> powershell.exe -command '&{write-host ""}'
The string is missing the terminator: ".
+ CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : TerminatorExpectedAtEndOfString
Works if the string has a character:
> powershell.exe -command '&{write-host "a"}'
a
Works by itself:
> &{write-host ""}
<blank line>
Works with reversed quotes:
>powershell.exe -command "&{write-host ''}"
<blank line>
And as #Ansgar pointed out escaping works (\ isn't documented in powershell.exe /?)
> powershell.exe -command '&{write-host \"\"}'
<blank line>

Answer 1

It appears to be using the at-string parser. The command ends up being:
#"'&{write-host ""}'"
which reduces to
'&{write-host "}'
The alternatives are:
# Like you said, escape the string
powershell.exe -command '&{write-host \"\"}'
# Use a script block instead of a string
powershell.exe -command {write-host ""}
You might also look into using a Base64 encoded command, but I've never gotten that to work.