gunixmounts: Add g_unix_mount_point_at

There is already g_unix_mount_at function which allows to find certain
unix mount for given mount path. It would be useful to have similar
function for mount points, which will allow to replace custom codes in
gvfs. Let's add g_unix_mount_point_at.

docs/reference/gio/gio-sections-common.txt

@@ -1572,6 +1572,7 @@ g_unix_mount_point_guess_symbolic_icon
 g_unix_mount_point_guess_name
 g_unix_mount_point_guess_can_eject
 g_unix_mount_points_get
+g_unix_mount_point_at
 g_unix_mounts_get
 g_unix_mount_at
 g_unix_mount_for

gio/gunixmounts.c

@@ -1660,6 +1660,52 @@ g_unix_mount_points_get (guint64 *time_read)
   return _g_get_unix_mount_points ();
 }
 
+/**
+ * g_unix_mount_point_at:
+ * @mount_path: (type filename): path for a possible unix mount point.
+ * @time_read: (out) (optional): guint64 to contain a timestamp.
+ *
+ * Gets a #GUnixMountPoint for a given mount path. If @time_read is set, it
+ * will be filled with a unix timestamp for checking if the mount points have
+ * changed since with g_unix_mount_points_changed_since().
+ *
+ * If more mount points have the same mount path, the last matching mount point
+ * is returned.
+ *
+ * Returns: (transfer full) (nullable): a #GUnixMountPoint, or %NULL if no match
+ * is found.
+ *
+ * Since: 2.66
+ **/
+GUnixMountPoint *
+g_unix_mount_point_at (const char *mount_path,
+                       guint64    *time_read)
+{
+  GList *mount_points, *l;
+  GUnixMountPoint *mount_point, *found;
+
+  mount_points = g_unix_mount_points_get (time_read);
+
+  found = NULL;
+  for (l = mount_points; l != NULL; l = l->next)
+    {
+      mount_point = l->data;
+
+      if (strcmp (mount_path, mount_point->mount_path) == 0)
+        {
+          if (found != NULL)
+            g_unix_mount_point_free (found);
+
+          found = mount_point;
+        }
+      else
+        g_unix_mount_point_free (mount_point);
+    }
+  g_list_free (mount_points);
+
+  return found;
+}
+
 /**
  * g_unix_mounts_changed_since:
  * @time: guint64 to contain a timestamp.

gio/gunixmounts.h

@@ -132,6 +132,9 @@ GIcon *        g_unix_mount_point_guess_symbolic_icon (GUnixMountPoint    *mount
 
 GLIB_AVAILABLE_IN_ALL
 GList *        g_unix_mount_points_get              (guint64            *time_read);
+GLIB_AVAILABLE_IN_2_66
+GUnixMountPoint *g_unix_mount_point_at              (const char         *mount_path,
+                                                     guint64            *time_read);
 GLIB_AVAILABLE_IN_ALL
 GList *        g_unix_mounts_get                    (guint64            *time_read);
 GLIB_AVAILABLE_IN_ALL