fix(windows): crash on out of bounds for root path cleanup

[manifestori]

I am using this lib in a tool I've been contributing to.

import builder_common "github.com/spdx/tools-golang/builder"

cwd, err := os.Getwd()
if err != nil {
	return nil, err
}

...
ref := &builder.Config{
		NamespacePrefix: "https://spdx.org/spdxdocs/",
		CreatorType:     "Tool",
		Creator:         "me",
}


builder_common.Build("mypackage", cwd, ref)

On Linux - no issues.
On Windows - I get out of bounds. Also, I tried running tests (without any modifications), but they fail (due to Windows path issues).
I tried my best to test it in the given state.

Also, note that I changed "." to ".\\" .
if a root path has "/" for suffix (ie. my\path\ ) this will not impose a problem ( .\my\file.txt equals '.\my\file.txt ). having only "." is problematic for cases where the root path includes \ and the rel path is just .file.txt and not .\file.txt

Im not a Windows Pro but this seems right

[kzantow]

Hi @manifestori; thanks for the contribution! It looks to me like this library should support Windows for some of this functionality, so I think we should make sure these code paths work by running the tests on Windows, too. I thought I'd give that a try, so I made a PR with a simple workflow to also run the existing tests on Windows. Unfortunately, it looks like there are some definite incompatibilities at least between the tests and Windows. I looked in to this last night a bit, and as expected, this is primarily due to path handling, but the fix in this PR also had some unexpected behavior where tests, at least, got double slashes e.g. .\\something rather than .\something. I don't use this functionality myself, but I'd like to try to make sure it works in expected ways for everyone. I'd love feedback about how to best handle Windows moving forward. I posed a question about the main issues I found when investigating here, if you had any thoughts, please do add them: #117 (comment)

[manifestori]

Yeah, as I expected .\\someting vs .\something I can make sure to add the correct prefix (. or .\)
they are equivalent, but I see why we would want to differentiate them.

Currently, I had to issue a prompt fix as this is currently broken; I will be using my fork until we resolve this, but I suggest we issue this as 0.5.5

I'll be happy to contribute to the test discussions as well, especially with the up-and-coming spdx3.0 support.

[manifestori]

@kzantow added trim to double slashes if input ended up having double slash (".\\\\" with escapes).
They are semantically equivalent but syntactically different anyway. wdyt?

[manifestori]

closing in favor of #242