Catch errors on datadir lock and pidfile delete

Prevents bad permissions (or other fs related problems) from resulting
in hard crashes with cryptic messages on startup and shutdown.

src/init.cpp

@@ -187,7 +187,11 @@ void Shutdown()
         pwalletMain->Flush(true);
 #endif
 #ifndef WIN32
-    boost::filesystem::remove(GetPidFile());
+    try {
+        boost::filesystem::remove(GetPidFile());
+    } catch (const boost::filesystem::filesystem_error& e) {
+        LogPrintf("%s: Unable to remove pidfile: %s\n", __func__, e.what());
+    }
 #endif
     UnregisterAllValidationInterfaces();
 #ifdef ENABLE_WALLET
@@ -862,9 +866,15 @@ bool AppInit2(boost::thread_group& threadGroup)
     boost::filesystem::path pathLockFile = GetDataDir() / ".lock";
     FILE* file = fopen(pathLockFile.string().c_str(), "a"); // empty lock file; created if it doesn't exist.
     if (file) fclose(file);
-    static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
-    if (!lock.try_lock())
-        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running."), strDataDir));
+
+    try {
+        static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
+        if (!lock.try_lock())
+            return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running."), strDataDir));
+    } catch(const boost::interprocess::interprocess_exception& e) {
+        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running.") + " %s.", strDataDir, e.what()));
+    }
+
 #ifndef WIN32
     CreatePidFile(GetPidFile(), getpid());
 #endif