From fb32374bb74ddbbf0bd3bf9fa3ea7387bd21c2dd Mon Sep 17 00:00:00 2001
From: Preston Hunt <me@prestonhunt.com>
Date: Sat, 29 Aug 2026 09:45:49 -0700
Subject: [PATCH] git: stop overwriting the user's identity on every run

The tracked gitconfig hard-coded a [user] section:

    [user]
        email = unknown@unknown.com
        name  = Unknown User

setup_git copies that file over ~/.gitconfig on every run, so every
provisioned machine silently had its git identity replaced by the
placeholder. Commits then get authored as 'Unknown User
<unknown@unknown.com>' with no error and no prompt -- git only refuses
to commit when an identity is absent, not when it is wrong.

Drop the [user] section from the shipped file, and have setup_git carry
the identity across the overwrite:

  - read user.name/user.email before the copy and restore them after
  - treat the old placeholder values as absent, so machines already
    clobbered by a previous run recover instead of keeping them
  - let GIT_USER_NAME / GIT_USER_EMAIL override (these can be exported,
    or set in config.local once that mechanism lands)
  - print the two commands to run when no identity can be determined,
    rather than leaving a config that looks populated but is wrong

Verified against throwaway HOMEs: a real identity is preserved; the
placeholder is discarded; a machine with no identity gets the hint; an
explicit GIT_USER_* wins over an existing value; and the aliases from
the shipped gitconfig are still installed in every case.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 gitconfig |  8 +++++---
 setup     | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/gitconfig b/gitconfig
index 44dabc8..facd56a 100644
--- a/gitconfig
+++ b/gitconfig
@@ -1,6 +1,8 @@
-[user]
-    email = unknown@unknown.com
-    name = Unknown User
+# NOTE: deliberately no [user] section. This file is copied over
+# ~/.gitconfig on every run, so hard-coding an identity here silently
+# replaces the real one on every machine it is installed to. setup_git
+# preserves whatever identity is already configured, or takes it from
+# GIT_USER_NAME / GIT_USER_EMAIL.
 
 [color]
     diff = auto
diff --git a/setup b/setup
index df939ed..31c3756 100755
--- a/setup
+++ b/setup
@@ -216,7 +216,39 @@ setup_ssh() {
 
 setup_git() {
     install_package git git-lfs
-    get_prestobuntu_file gitconfig $HOME/.gitconfig
+
+    # ~/.gitconfig is overwritten wholesale below, so capture any
+    # identity already configured and put it back afterwards. Ignore the
+    # old placeholder, which earlier versions of this script installed.
+    local name email
+    name=$(git config --global --get user.name || true)
+    email=$(git config --global --get user.email || true)
+    if [[ $name == "Unknown User" ]]; then
+        name=""
+    fi
+    if [[ $email == "unknown@unknown.com" ]]; then
+        email=""
+    fi
+
+    get_prestobuntu_file gitconfig "$HOME/.gitconfig"
+
+    # An explicit setting wins over whatever was there before. These may
+    # be exported, or set in config.local once that mechanism lands.
+    name=${GIT_USER_NAME:-$name}
+    email=${GIT_USER_EMAIL:-$email}
+
+    if [[ -n $name ]]; then
+        git config --global user.name "$name"
+    fi
+    if [[ -n $email ]]; then
+        git config --global user.email "$email"
+    fi
+
+    if [[ -z $name || -z $email ]]; then
+        info "git identity not set; run:"
+        info "  git config --global user.name 'Your Name'"
+        info "  git config --global user.email 'you@example.com'"
+    fi
 }
 
 get_internet_file() {