Git Diagnostics shows giant merge conflict message

[Arcanemagus]

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

If you attempt to pull a repository that has local changes that would be overridden by the incoming commits (say, updates to a package-lock.json), you get an error message with the entire debug output. With Git Diagnostics enabled this includes far too much information to display directly.

Steps to Reproduce

1. Checkout a repo (e.g. atom/atom@64fc36f)
2. Make a local change (to package-lock.json)
3. Enable "Git Diagnostics" in the settings
4. Attempt to pull down changes from the remote repo.

Expected behavior:

The merge conflict to be caught and presented nicely to the user.

Note that if the Git Diagnostics option is disabled the standard git output looks decent enough:

Actual behavior:

A giant error box shows the entire verbose output of the git command:

Uncaught (in promise) GitError: git pull origin master in C:\temp\atom exited with code 1
stdout: Updating 64fc36f66..5e64cdcf1

stderr: 13:48:21.751414 exec_cmd.c:236          trace: resolved executable dir: C:/Users/abneyl/Documents/GitHub/github/node_modules/dugite/git/mingw64/bin
13:48:21.754414 git.c:344               trace: built-in: git pull origin master
13:48:21.763419 run-command.c:640       trace: run_command: git fetch --update-head-ok origin master
13:48:21.776417 exec_cmd.c:236          trace: resolved executable dir: C:/Users/abneyl/Documents/GitHub/github/node_modules/dugite/git/mingw64/bin
13:48:21.778418 git.c:344               trace: built-in: git fetch --update-head-ok origin master
13:48:21.810414 run-command.c:640       trace: run_command: git remote-https origin https://github.com/atom/atom.git
13:48:21.823434 exec_cmd.c:236          trace: resolved executable dir: C:/Users/abneyl/Documents/GitHub/github/node_modules/dugite/git/mingw64/bin
13:48:21.825433 git.c:576               trace: exec: git-remote-https origin https://github.com/atom/atom.git
13:48:21.825433 run-command.c:640       trace: run_command: git-remote-https origin https://github.com/atom/atom.git
13:48:21.842417 exec_cmd.c:236          trace: resolved executable dir: C:/Users/abneyl/Documents/GitHub/github/node_modules/dugite/git/mingw64/bin
13:48:21.849412 http.c:709              == Info: Couldn't find host github.com in the _netrc file; using defaults
13:48:21.855419 http.c:709              == Info:   Trying 192.30.255.112...
13:48:21.855419 http.c:709              == Info: TCP_NODELAY set
13:48:21.883414 http.c:709              == Info: Connected to github.com (192.30.255.112) port 443 (#0)
13:48:21.883414 http.c:709              == Info: schannel: SSL/TLS connection with github.com port 443 (step 1/3)
... several MiB (?) of output

Reproduces how often:

100% of the time.

Versions

An Atom build based on atom/atom@64fc36f, running github from 45b46f0.

Atom    : 1.33.0-dev-64fc36f66
Electron: 2.0.9
Chrome  : 61.0.3163.100
Node    : 8.9.3
apm  2.1.2
npm  6.2.0
node 8.9.3 x64
atom 1.33.0-dev-64fc36f66
python 2.7.15
git 2.19.0.windows.1
visual studio 2015

Additional Information

As this only shows when a diagnostic option is enabled, this is low priority at best 😉.