correct shellQuote on windows

[victor-shepardson]

Motivation

Not exactly a bug since the helpfile is clear, but String.shellQuote is not useful on windows, since single quotes don't work to escape space in cmd.exe. Would it make sense for shellQuote to be platform sensitive like +/+ is?

Description of Proposed Feature

Make shellQuote use double quotes when the platform is windows.

I think it's sufficient to add the quotes, existing double quotes need not be escaped since they are forbidden from paths on windows. Maybe someone more familiar with cmd.exe can weigh in. Should the presence of double quotes in the string cause a warning or error?

Plan for Implementation

shellQuote {
    (thisProcess.platform.name==\windows).if{
        ^"\""++this++"\""
    }{
        ^"'"++this.replace("'","'\\''")++"'"
    }
}

This would be a breaking change on windows.

[victor-shepardson]

there is at least one problem with the above, it causes paths with a trailing \ to result in an escaped ", like C:\some\path\ quotes to 'C:\some\path\" but by cmd.exe as C:\some\path\" because of the \"

[victor-shepardson]

could be like this, with bashShellQuote preserving the old behavior:

cmdShellQuote {
    var str = this;
    // drop trailing slashes so they don't escape the " character
    while{str.endsWith("\\")}{str = str.drop(-1)};
    ^ str.quote
}
bashShellQuote {
    ^ "'"++this.replace("'","'\\''")++"'"
}
shellQuote {
    ^ (thisProcess.platform.name==\windows).if{ this.cmdShellQuote }{ this.bashShellQuote };
}