cli: --disk: Don't try to detect path opt collisions

The checking is hard to get right because there are many ways to
specify storage. Rework it to try to determine if we should
create storage from disk XML contents

Author: crobinso

virtinst/cli.py

@@ -2799,7 +2799,6 @@ def convert_perms(val):
             else:
                 fail(_("Unknown '%s' value '%s'") % ("perms", val))
 
-        has_path = "path" in self.optdict
         backing_store = self.optdict.pop("backing_store", None)
         backing_format = self.optdict.pop("backing_format", None)
         poolname = self.optdict.pop("pool", None)
@@ -2808,17 +2807,6 @@ def convert_perms(val):
         fmt = self.optdict.pop("format", None)
         sparse = _on_off_convert("sparse", self.optdict.pop("sparse", "yes"))
         convert_perms(self.optdict.pop("perms", None))
-        has_type_volume = ("source_pool" in self.optdict or
-                           "source_volume" in self.optdict)
-        has_type_network = ("source_protocol" in self.optdict)
-
-        optcount = sum([bool(p) for p in [has_path, poolname, volname,
-                                          has_type_volume, has_type_network]])
-        if optcount > 1:
-            fail(_("Cannot specify more than 1 storage path"))
-        if optcount == 0 and size:
-            # Saw something like --disk size=X, have it imply pool=default
-            poolname = "default"
 
         if volname:
             if volname.count("/") != 1:
@@ -2830,6 +2818,14 @@ def convert_perms(val):
 
         super()._parse(inst)
 
+        if (size and
+            not volname and
+            not poolname and
+            not inst.path and
+            inst.type == inst.TYPE_FILE):
+            # Saw something like --disk size=X, have it imply pool=default
+            poolname = "default"
+
         # Generate and fill in the disk source info
         newvolname = None
         poolobj = None