Fix #4139 - escape quoted strings for process start

[natemcmaster]

Resolves #4139. I got burned by this again recently. It seems the fix is pretty simple. Don't special case arguments that begin/end in quotes already.

[natemcmaster]

@dotnet-bot test OSX10.12 x64 Release Build please

[ghost]

Does it fix/break or has any impact on cmd and powershell if you run dotnet run a b '" c "' d?
The reason I am asking is I have seen people handling escaping differently in Unix vs. Windows.

[natemcmaster]

Yes, the fix has impact on Windows too. For example, in cmd:

Before:

> dotnet run """As they say, live and learn."""
0 = "As
1 = they
2 = say,
3 = live
4 = and
5 = learn."

> dotnet bin\Debug\netcoreapp2.1\test2.dll """As they say, live and learn."""
0 = "As they say, live and learn."

After

> dotnet run """As they say, live and learn."""
0 = "As they say, live and learn."

> dotnet bin\Debug\netcoreapp2.1\test2.dll """As they say, live and learn."""
0 = "As they say, live and learn."

[natemcmaster]

Thanks for the review @livarcocc @peterhuene. I don't have write access to this repo so feel free to merge this when you are ready to bring it in.

[livarcocc]

Just want to note that strictly speaking, this is a breaking change, albeit I believe this is a great one. We have the wrong behavior in run and it differs when actually running the app.

FYI @KathleenDollard

I will give it a day for folks to see this message and then I will merge this tomorrow.

[peterhuene]

@livarcocc good to merge?

[livarcocc]

Go ahead.