stage files from merge group properly

[akosyakov]

fix #5455

How to test

• Follow https://stackoverflow.com/questions/43702944/reproducing-git-merge-conflict-dd to create a repo with merge conflicts
• Check that stage and stage all commands are working from merge group

[akosyakov]

cc @32leaves

[kittaakos]

I could not spot any difference between the changes from here and the master; I ran into an error with both states: #5463. Other than the error, when I staged and unstaged the files, both behaved the same.

[akosyakov]

You should be able to stage from merge conflicts. On master it does not work for individual files. It can only stage from changes.

[AlexTugarev]

the way it was before should be good. this line breaks it. can you explain the intent, please?

I cannot stage this new change to a file which already was staged before.

[AlexTugarev]

Maybe we should express the condition clearly; is this what you wanted to check for?

const dirty = unstagedChanges.some(change => chan`ge.uri === uri) || mergeChanges.some(change => change.uri === uri);

[AlexTugarev]

just tested quickly; with the proposed change I could stage changes for already staged files and it played well with the merge conflict changes.

[akosyakov]

@AlexTugarev @kittaakos please feel free to open an alternative PR, i won't be around today

[AlexTugarev]

@kittaakos, I've update this PR. Please have a look.

[kittaakos]

I cannot stage this new change to a file which already was staged before.

It worked. 👍

[kittaakos]

I am approving this; however, I was not able to reproduce the original issue from the master.

[akosyakov]

just had it again, pretty annoying that it is not possible to stage one file after another, merging it