Coalesce concurrent shell restarts

bin/omarchy-restart-shell

@@ -11,6 +11,13 @@ session_omarchy_path=$(systemctl --user show-environment 2>/dev/null | sed -n 's
 CONFIG_DIR="$session_omarchy_path/shell"
 [[ -f $CONFIG_DIR/shell.qml ]] || { echo "Omarchy shell config not found: $CONFIG_DIR" >&2; exit 1; }
 
+# A double-click or two setup helpers can request a restart at the same time.
+# The first invocation already satisfies every overlapping request; letting a
+# second one enter the kill loop can terminate the replacement shell while it
+# is still starting. Coalesce concurrent restarts instead.
+exec {restart_lock_fd}>"${XDG_RUNTIME_DIR:-/tmp}/omarchy-restart-shell.lock"
+flock -n "$restart_lock_fd" || exit 0
+
 # Allow running from outside the session (e.g. over ssh) by deriving the
 # Hyprland instance signature from the newest instance runtime dir.
 if [[ -z ${HYPRLAND_INSTANCE_SIGNATURE:-} ]]; then

test/shell.d/restart-shell-concurrency-test.sh

@@ -0,0 +1,70 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+require_command flock
+
+test_tmp=$(mktemp -d)
+holder_pid=""
+
+cleanup() {
+  [[ -n $holder_pid ]] && kill "$holder_pid" 2>/dev/null || true
+  [[ -n $holder_pid ]] && wait "$holder_pid" 2>/dev/null || true
+  rm -rf "$test_tmp"
+}
+trap cleanup EXIT
+
+session_root="$test_tmp/session"
+runtime_dir="$test_tmp/runtime"
+mock_bin="$test_tmp/bin"
+marker="$test_tmp/restart-progressed"
+ready="$test_tmp/lock-ready"
+mkdir -p "$session_root/shell" "$runtime_dir" "$mock_bin"
+touch "$session_root/shell/shell.qml"
+
+cat >"$mock_bin/systemctl" <<'SH'
+#!/bin/bash
+if [[ ${1:-} == "--user" && ${2:-} == "show-environment" ]]; then
+  printf 'OMARCHY_PATH=%s\n' "$OMARCHY_TEST_SESSION_PATH"
+else
+  exit 1
+fi
+SH
+
+for command in omarchy-hyprland-session-locked omarchy-shell quickshell hyprctl; do
+  cat >"$mock_bin/$command" <<'SH'
+#!/bin/bash
+touch "$OMARCHY_TEST_MARKER"
+exit 99
+SH
+  chmod +x "$mock_bin/$command"
+done
+chmod +x "$mock_bin/systemctl"
+
+(
+  exec 9>"$runtime_dir/omarchy-restart-shell.lock"
+  flock 9
+  touch "$ready"
+  sleep 30
+) &
+holder_pid=$!
+
+for (( attempt = 0; attempt < 100; attempt++ )); do
+  [[ -f $ready ]] && break
+  sleep 0.01
+done
+[[ -f $ready ]] || fail "test acquired the shell restart lock"
+
+PATH="$mock_bin:$PATH" \
+OMARCHY_PATH="$session_root" \
+XDG_RUNTIME_DIR="$runtime_dir" \
+HYPRLAND_INSTANCE_SIGNATURE=test \
+OMARCHY_TEST_SESSION_PATH="$session_root" \
+OMARCHY_TEST_MARKER="$marker" \
+  timeout 1 "$ROOT/bin/omarchy-restart-shell" ||
+  fail "overlapping shell restart is coalesced successfully"
+
+[[ ! -e $marker ]] || fail "overlapping shell restart does not enter the restart sequence"
+pass "overlapping shell restart is coalesced before it can kill the replacement shell"