Don't probe virtual devices before they exist

src/mm-plugin-base.c

 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details:
  *
  * Copyright (C) 2008 - 2009 Novell, Inc.
  * Copyright (C) 2009 Red Hat, Inc.
  */
 
 #define _GNU_SOURCE  /* for strcasestr */
 
 #include <stdio.h>
 #include <stdlib.h>
+
+#include <sys/stat.h>
 #include <unistd.h>
 
 #include <string.h>
 
 #define G_UDEV_API_IS_SUBJECT_TO_CHANGE
 #include <gudev/gudev.h>
 
 #include "mm-plugin-base.h"
 #include "mm-serial-port.h"
 #include "mm-serial-parsers.h"
@@ skipping 860 matching lines @@
         }
 
         old = iter;
         iter = g_udev_device_get_parent (old);
         g_object_unref (old);
     }
 
     return physdev;
 }
 
+static gboolean
+device_file_exists(const char *name)
+{
+    char *devfile;
+    struct stat s;
+    int result;
+
+    devfile = g_strdup_printf ("/dev/%s", name);
+    result = stat (devfile, &s);
+    g_free (devfile);
+
+    return (0 == result) ? TRUE : FALSE;
+}
+
 static MMPluginSupportsResult
 supports_port (MMPlugin *plugin,
                const char *subsys,
                const char *name,
                MMSupportsPortResultFunc callback,
                gpointer callback_data)
 {
     MMPluginBase *self = MM_PLUGIN_BASE (plugin);
     MMPluginBasePrivate *priv = MM_PLUGIN_BASE_GET_PRIVATE (self);
     GUdevDevice *port = NULL, *physdev = NULL;
@@ skipping 12 matching lines @@
     }
 
     port = g_udev_client_query_by_subsystem_and_name (priv->client, subsys, name);
     if (!port)
         goto out;
 
     // Detect any modems accessible through the list of virtual ports
     for (idx = 0; virtual_port[idx]; idx++)  {
         if (strcmp(name, virtual_port[idx]))
             continue;
+
+        if (!device_file_exists(virtual_port[idx]))
+            continue;
+
         task = supports_task_new (self, port, port, "virtual", callback, callback_data);
         g_assert (task);
         g_hash_table_insert (priv->tasks, g_strdup (key), g_object_ref (task));
         master_path = g_udev_device_get_sysfs_path (port);
         goto find_plugin;
     }
 
     physdev = MM_PLUGIN_BASE_GET_CLASS (self)->find_physical_device (self, port);
     if (!physdev)
         goto out;
@@ skipping 190 matching lines @@
 
     signals[PROBE_RESULT] =
         g_signal_new ("probe-result",
                       G_OBJECT_CLASS_TYPE (object_class),
                       G_SIGNAL_RUN_FIRST,
                       G_STRUCT_OFFSET (MMPluginBaseClass, probe_result),
                       NULL, NULL,
                       mm_marshal_VOID__OBJECT_UINT,
                       G_TYPE_NONE, 2, G_TYPE_OBJECT, G_TYPE_UINT);
 }