Not sure if from, to in diff.FilePatch.Files() is reversed

[zregvart]

I'm trying to go through the log of a repository and output if a file has been added, deleted or modified.

This is the code should print a line with +, - or ~ on the first column of the line if a file has been added, deleted or modified in a particular commit.

When looking at a commit that added a file, the to is nil and from has a diff.File instance, and reading the documentation I though it should be the other way around:

If the patch creates a new file, "from" will be nil. If the patch deletes a file, "to" will be nil.

To see this for yourself do this:

$ git clone https://github.com/zregvart/go-git-patch.git
$ cd go-git-patch
$ go run main.go

This prints:

eee9efe5c3b8311253587860099f5e15331c90fb
~ README.md
09e0083ccdea187c3c5a4441884e2f505f5f604c
~ README.md
648875269a3450e467c8948d338767ca1f07b481
+ go.mod
+ go.sum
+ main.go

And I'm expecting it to print:

eee9efe5c3b8311253587860099f5e15331c90fb
~ README.md
09e0083ccdea187c3c5a4441884e2f505f5f604c
+ README.md
648875269a3450e467c8948d338767ca1f07b481
+ go.mod
+ go.sum
+ main.go

That is, in 09e0083ccdea187c3c5a4441884e2f505f5f604c the README.md is added and should be prefixed with +.

What am I doing wrong?

[AriehSchneier]

I think your lines 51 and 52 are incorrect/back to front. Patch gives you the patch from 1 commit to the next, so you want from the parent to the child, ie your code should look something like:

			parent := result(c.Parent(0))
			p := result(parent.Patch(c))

[zregvart]

That was it, thank you!