From 47daef1e47ea4ba3556f17bcb4ed5b08897fd876 Mon Sep 17 00:00:00 2001
From: Calum Lind <calumlind+deluge@gmail.com>
Date: Thu, 2 Oct 2014 17:15:00 +0100
Subject: [PATCH] [#2335] [GTKUI] Fix startup failing with 'cannot acquire
 lock'

This issue was caused by an unclean shutdown of Deluge, usually on system shutdown, and upon rebooting
the PID stored in the lockfile is in used by another process thus the lockfile is never removed. It
affects users with Deluge set in startup applications as the PIDs are more likely to be reused.

 * Lockfile is removed if Deluge is restarted in IPC.
 * Renamed the old_tempfile variable to make it clearer as to it's role.
---
 deluge/ui/gtkui/ipcinterface.py | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/deluge/ui/gtkui/ipcinterface.py b/deluge/ui/gtkui/ipcinterface.py
index 222001c09..9b79bb990 100644
--- a/deluge/ui/gtkui/ipcinterface.py
+++ b/deluge/ui/gtkui/ipcinterface.py
@@ -120,24 +120,28 @@ class IPCInterface(component.Component):
                 sys.exit(0)
         else:
             # Find and remove any restart tempfiles
-            old_tempfile = glob(os.path.join(ipc_dir, 'tmp*deluge'))
-            for f in old_tempfile:
+            restart_tempfile = glob(os.path.join(ipc_dir, 'tmp*deluge'))
+            for f in restart_tempfile:
                 os.remove(f)
             lockfile = socket + ".lock"
             log.debug("Checking if lockfile exists: %s", lockfile)
-            if os.path.lexists(lockfile) or os.path.lexists(socket):
-                try:
-                    os.kill(int(os.readlink(lockfile)), 0)
-                except OSError:
+            if os.path.lexists(lockfile):
+                def delete_lockfile():
                     log.debug("Removing lockfile since it's stale.")
                     try:
                         os.remove(lockfile)
-                    except OSError, ex:
-                        log.error("Failed to delete IPC lockfile file: %s", ex)
-                    try:
                         os.remove(socket)
-                    except OSError, ex:
-                        log.error("Failed to delete IPC socket file: %s", ex)
+                    except OSError as ex:
+                        log.error("Failed to delete lockfile: %s", ex)
+
+                try:
+                    os.kill(int(os.readlink(lockfile)), 0)
+                except OSError:
+                    delete_lockfile()
+                else:
+                    if restart_tempfile:
+                        log.warning("Found running PID but it is not a Deluge process, removing lockfile...")
+                        delete_lockfile()
             try:
                 self.factory = Factory()
                 self.factory.protocol = IPCProtocolServer
@@ -154,7 +158,7 @@ class IPCInterface(component.Component):
                     gtk.gdk.notify_startup_complete()
                     sys.exit(0)
                 else:
-                    if old_tempfile:
+                    if restart_tempfile:
                         log.error("Deluge restart failed: %s", e)
                         sys.exit(1)
                     else: