VirtualDisk: If path is overwritten, invalidate cached storage objects.

Author: crobinso

tests/xmlconfig-xml/install-f11-xen.xml

@@ -30,8 +30,7 @@
       <source dev='/dev/loop0'/>
       <target dev='hdb' bus='ide'/>
     </disk>
-    <disk type='file' device='cdrom'>
-      <source file='/default-pool/default-vol'/>
+    <disk type='block' device='cdrom'>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>

tests/xmlconfig-xml/install-f11.xml

@@ -29,8 +29,7 @@
       <source dev='/dev/loop0'/>
       <target dev='vdb' bus='virtio'/>
     </disk>
-    <disk type='file' device='cdrom'>
-      <source file='/default-pool/default-vol'/>
+    <disk type='block' device='cdrom'>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>

virtinst/VirtualDisk.py

@@ -385,6 +385,12 @@ def _set_path(self, val, validate=True):
         if val is not None:
             self._check_str(val, "path")
             val = os.path.abspath(val)
+
+        if validate:
+            self._vol_install = None
+            self._vol_object = None
+            self._type = None
+
         self.__validate_wrapper("_path", val, validate)
     path = property(_get_path, _set_path)