Import alt-mysql plugin

tests/mysql_upgrade_rollback_test.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+set -euo pipefail
+
+PLUGIN_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+SCRIPT="$PLUGIN_DIR/scripts/setup/mysql_upgrade.sh"
+
+fail() {
+  echo "FAIL: $*" >&2
+  exit 1
+}
+
+grep -Fq "rollback_upgrade()" "$SCRIPT" \
+  || fail "mysql_upgrade.sh does not define rollback_upgrade"
+grep -Fq "UPGRADE_COMMITTED=1" "$SCRIPT" \
+  || fail "mysql_upgrade.sh does not mark successful upgrades as committed"
+grep -Fq 'trap '\''code=$?; rollback_upgrade "$code"'\'' EXIT' "$SCRIPT" \
+  || fail "mysql_upgrade.sh does not run rollback on failed exit"
+grep -Fq "RESTORED_PREVIOUS_DIR" "$SCRIPT" \
+  || fail "mysql_upgrade.sh does not restore previous binary directory"
+grep -Fq "RESTORED_INSTANCE_CNF" "$SCRIPT" \
+  || fail "mysql_upgrade.sh does not restore previous instance config"
+
+echo "mysql_upgrade_rollback_test: OK"