Unstaged changes pane loses green background in specific cases

[robertrossmann]

Prerequisites

• Have you tried to reproduce the problem in Safe Mode?
• Have you followed all applicable steps in the debugging guide?
• Have you checked the FAQs on the message board for common solutions?
• Have you checked that your issue isn't already filed?

Description

With the Unstaged Changes pane open, deleting contents of an untracked file (select all -> delete) and adding them back in a single step (undo last) results in the Unstaged Changes pane to lose the green background.

Steps to Reproduce

1. Create a new and untracked file and write some contents into it
2. Open the unstaged changes pane and keep it open
3. Delete the contents of the new file in a single step (select all -> delete)
4. Undo last operation (usually cmd/ctrl-z)
5. Observe Unstaged changes to no longer have green background

Expected behavior:

Green background should be added to all the lines when the file's contents are returned to the file

Actual behavior:

No green background, only text

Reproduces how often:

100% of the time

Versions

Atom    : 1.34.0-beta0
Electron: 2.0.14
Chrome  : 61.0.3163.100
Node    : 8.9.3

Additional Information

Screenshots follow.

Note that I was unable to reproduce this issue when re-inserting a previously deleted contents from an already-tracked file (ie. a diff with red background). The red background always properly returns to the Unstaged changes pane regardless of how many times I try to delete the tracked file's contents and put them back in a single step.

Initial state (correct)

File contents deleted (correct)

File contents returned - green background missing (incorrect) ⚠️

[rsese]

Thanks for the detailed report and screenshots @robertrossmann 🙇 - reproduced on macOS 10.12.6 with 1.34.0-beta0.

[Arcanemagus]

I think I'm seeing this with a removed line:

As you can see from the line numbers on the left for the selected text it knows that something about that line is able to tbe staged, but the red highlight for it getting moved isn't showing.

Unfortunately closing the diff view and re-opening it fixed this, so I don't have consistent steps to reproduce it.

Seen on:
OS: Windows 10 x64

Atom    : 1.37.0-nightly9
Electron: 2.0.16
Chrome  : 61.0.3163.100
Node    : 8.9.3

github@0.26.0