fix(linux): keep the Service through released rpm %preun via uninstaller wrapper

Refs #8515

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src-tauri/packages/linux/post-install-rpm.sh

@@ -3,17 +3,28 @@ set -e
 
 chmod +x /usr/bin/clash-verge-service-install
 chmod +x /usr/bin/clash-verge-service-uninstall
+chmod +x /usr/lib/clash-verge-rev/clash-verge-service-uninstall
 chmod +x /usr/bin/clash-verge-service
 
 SERVICE_UNIT="clash-verge-service.service"
 SERVICE_UNIT_FILE="/etc/systemd/system/$SERVICE_UNIT"
 # Read by the app, which offers a reinstall when the package could not keep the Service.
 UPGRADE_MARKER="/run/clash-verge-service-upgrade"
+# Read by /usr/bin/clash-verge-service-uninstall to keep the Service through the previous %preun.
+TRANSACTION_RECORD="/run/clash-verge-service-rpm-upgrade"
 
 write_upgrade_marker() {
     (umask 022 && printf 'gid=%s\nid=%s\n' "$1" "$(date +%s%N)" >"$UPGRADE_MARKER")
 }
 
+# Scriptlets run as children of the process running the rpm transaction; its start time
+# keeps a stale record from matching a later process that reuses the PID.
+record_transaction() {
+    local start
+    start="$(sed 's/.*) //' "/proc/$PPID/stat" | cut -d' ' -f20)"
+    (umask 022 && printf '%s %s\n' "$PPID" "$start" >"$TRANSACTION_RECORD")
+}
+
 existing_service_gid() {
     local group
     group="$(sed -n 's/^Group=//p' "$SERVICE_UNIT_FILE" | head -n 1)"
@@ -52,9 +63,10 @@ reinstall_existing_service() {
 
 # Upgrades keep an existing Service current; first installs and explicit removals never add one.
 # A symlinked unit is masked or managed by the administrator and is left alone.
-# The marker is written first: a previous package whose %preun uninstalls unconditionally
-# still removes the Service after this script, and the app only acts on it if the Service is not ready.
+# The previous %preun runs after this script; the record keeps it from removing the Service.
+# The marker stays as a fallback should it still be removed; the app only acts on it if the Service is not ready.
 if [ "$1" -ge 2 ] && [ -d /run/systemd/system ] && [ -f "$SERVICE_UNIT_FILE" ] && [ ! -L "$SERVICE_UNIT_FILE" ]; then
+    record_transaction || true
     gid="$(existing_service_gid)"
     write_upgrade_marker "$gid"
     if [ -z "$gid" ]; then

src-tauri/packages/linux/post-install.sh

@@ -1,6 +1,7 @@
 #!/bin/bash
 chmod +x /usr/bin/clash-verge-service-install
 chmod +x /usr/bin/clash-verge-service-uninstall
+chmod +x /usr/lib/clash-verge-rev/clash-verge-service-uninstall
 chmod +x /usr/bin/clash-verge-service
 
 SERVICE_UNIT="clash-verge-service.service"

src-tauri/packages/linux/service-uninstall.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+# Installed as /usr/bin/clash-verge-service-uninstall. During an rpm upgrade the new %post
+# reinstalls an existing Service before the previous package's %preun runs, and released
+# %preun scripts uninstall it unconditionally through this path. Skip only that call: one
+# made by a scriptlet of the transaction that %post recorded.
+RECORD=/run/clash-verge-service-rpm-upgrade
+UNINSTALLER=/usr/lib/clash-verge-rev/clash-verge-service-uninstall
+
+# Fields after the parenthesised command name, which may itself contain spaces.
+stat_field() {
+    sed 's/.*) //' "/proc/$1/stat" 2>/dev/null | cut -d' ' -f"$2"
+}
+
+if [ -f "$RECORD" ] && [ ! -L "$RECORD" ] && read -r txn_pid txn_start <"$RECORD"; then
+    pid=$PPID
+    depth=0
+    while [ "$depth" -lt 4 ] && [ -n "$pid" ] && [ "$pid" -gt 1 ]; do
+        if [ "$pid" = "$txn_pid" ] && [ "$(stat_field "$pid" 20)" = "$txn_start" ]; then
+            rm -f "$RECORD"
+            echo "Keeping the Clash Verge Service reinstalled by this upgrade."
+            exit 0
+        fi
+        pid="$(stat_field "$pid" 2)"
+        depth=$((depth + 1))
+    done
+fi
+
+exec "$UNINSTALLER" "$@"