From 8a58df684d935cf7d980fa9692241dcfb1a882d8 Mon Sep 17 00:00:00 2001
From: anttiharju <git@anttiharju.dev>
Date: Sun, 13 Oct 2024 18:25:17 +0300
Subject: [PATCH] Save `deprecate-email` script

For many years this was in a Google Keep note, so really good
to properly version control it now.
---
 bin/deprecate-email | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100755 bin/deprecate-email

diff --git a/bin/deprecate-email b/bin/deprecate-email
new file mode 100755
index 0000000..02002f4
--- /dev/null
+++ b/bin/deprecate-email
@@ -0,0 +1,38 @@
+#!/usr/bin/env dash
+set -eu
+
+# deprecate-email:
+# Sometimes I remove email addresses from my GitHub profile. This makes the contributions in my profile disappear as the email address is no longer associated with my account. This script replaces commits with input email with current git config.
+
+if [ -z "$1" ]; then
+  echo "Error: old_email argument is required."
+  exit 1
+fi
+
+old_email="$1"
+new_email="$(git config user.email)"
+new_name="$(git config user.name)"
+
+# Replacing author and committer emails has to be done separately to avoid unintentional overwrites
+# e.g. in commits with multiple authors.
+(export FILTER_BRANCH_SQUELCH_WARNING=1 && \
+echo "1/2 Overwriting committer" && \
+git filter-branch -f --commit-filter "
+	if [ \"\$GIT_COMMITTER_EMAIL\" = \"$old_email\" ];
+	then
+		GIT_COMMITTER_NAME=\"$new_name\";
+		GIT_COMMITTER_EMAIL=\"$new_email\";
+		git commit-tree \"\$@\";
+	else
+		git commit-tree \"\$@\";
+	fi" HEAD && \
+echo "2/2 Overwriting author" && \
+git filter-branch -f --commit-filter "
+	if [ \"\$GIT_AUTHOR_EMAIL\" = \"$old_email\" ];
+	then
+		GIT_AUTHOR_NAME=\"$new_name\";
+		GIT_AUTHOR_EMAIL=\"$new_email\";
+		git commit-tree \"\$@\";
+	else
+		git commit-tree \"\$@\";
+	fi" HEAD)