omnicache conversion tweak (#268)

* Add conversion test case for existence of old YAML configuration file
* Update validation routine to detect the presence of old config file

edk2toolext/omnicache.py

@@ -74,6 +74,9 @@ def _ValidateOmnicache(self):
             logging.debug("{0} error getting repo state - not valid (not convertible).".format(self.path))
             return (False, False)
         if (out.getvalue().strip().lower() == "true"):
+            if (os.path.exists(os.path.join(self.path, PRE_0_11_OMNICACHE_FILENAME))):
+                logging.debug("{0} - old config file present. not valid (is convertible).".format(self.path))
+                return (False, True)
             out = StringIO()
             ret = RunCmd("git", "config --local omnicache.metadata.version", workingdir=self.path, outstream=out)
             if (ret != 0):

edk2toolext/tests/test_omnicache.py

@@ -238,6 +238,18 @@ def test_omnicache_convert(self):
         assert(gitret == 0)
         assert(out.getvalue().strip() == "")
 
+        # add an empty file to simulate the old config yaml, but leave metadata in place.
+        # this simulates the case where an old version of omnicache ran and updated the remotes
+        # with some non-UUID versions, but the metadata version still exists. In this case, conversion
+        # should be run to cleanup the remotes.
+        with open(os.path.join(testcache, omnicache.PRE_0_11_OMNICACHE_FILENAME), "w") as yf:
+            yf.write("Not A Real YAML File")
+
+        # confirm that _ValidateOmnicache correctly identifies cache state
+        (valid, convertible) = oc._ValidateOmnicache()
+        assert(not valid)
+        assert(convertible)
+
     def test_omnicache_add_remove(self):
         testcache = os.path.join(os.path.abspath(os.getcwd()), test_dir, "testcache")