StringBuilder.appendQuotedIfNotNull is used incorrectly.

[teo-tsirpanis]

In

FAKE/src/app/Fake.Core.String/StringBuilder.fs

Lines 69 to 75 in 8dbf221

	let inline appendQuotedIfNotNull (value: Object) s (builder: StringBuilder) =
	if (value = null) then
	builder
	else
	(match value with
	| :? String as sv -> builder.Append(sprintf "%s\"%s\" " s sv)
	| _ -> builder.Append(sprintf "%s\"%A\" " s value))

we are appending nothing if value is null, but if it isn't we append both s and value.

This doesn't work well with code like

FAKE/src/app/Fake.DotNet.MSBuild/MSBuild.fs

Lines 684 to 687 in 8dbf221

	let internal quoteString str =
	StringBuilder()
	|> StringBuilder.appendQuotedIfNotNull Some str
	|> StringBuilder.toText

value is Some, which is a function, and displaying does not make any sense, leading to errors like https://ci.appveyor.com/project/teo-tsirpanis/farkle/builds/45896483/job/9et0xrw72ibtg3ar#L6292.

[yazeedobaid]

@teo-tsirpanis thanks for reporting, can you send a PR?

[teo-tsirpanis]

I can't understand what the correct code would be. I would have already sent it if I could. 😅

[teo-tsirpanis]

@yazeedobaid I want to fix the bug, can you help me understand it? What should appendQuotedIfNotNull do?

[yazeedobaid]

@teo-tsirpanis the function should escape quotations in the passed string if it has any. It is being discussed in this PR #2739