1 files changed, 22 insertions, 1 deletions

diff --git a/bitbake/lib/bb/fetch/__init__.py b/bitbake/lib/bb/fetch/__init__.py
index 39a8180a89..a97138d271 100644
--- a/bitbake/lib/bb/fetch/__init__.py
+++ b/bitbake/lib/bb/fetch/__init__.py
@@ -97,13 +97,34 @@ def fetcher_init(d):
         bb.msg.debug(1, bb.msg.domain.Fetcher, "Keeping SRCREV cache due to cache policy of: %s" % srcrev_policy)
     elif srcrev_policy == "clear":
         bb.msg.debug(1, bb.msg.domain.Fetcher, "Clearing SRCREV cache due to cache policy of: %s" % srcrev_policy)
-        pd.delDomain("BB_URI_HEADREVS")
+        pd.renameDomain("BB_URI_HEADREVS", "BB_URI_HEADREVS_PREVIOUS")
     else:
         bb.msg.fatal(bb.msg.domain.Fetcher, "Invalid SRCREV cache policy of: %s" % srcrev_policy)
     # Make sure our domains exist
     pd.addDomain("BB_URI_HEADREVS")
+    pd.addDomain("BB_URI_HEADREVS_PREVIOUS")
     pd.addDomain("BB_URI_LOCALCOUNT")
 
+def fetcher_compare_revisons(d):
+    """
+    Compare the revisions in the persistant cache with current values and
+    return true/false on whether they've changed.
+    """
+
+    pd = persist_data.PersistData(d)
+    data = pd.getKeyValues("BB_URI_HEADREVS")
+    data2 = pd.getKeyValues("BB_URI_HEADREVS_PREVIOUS")
+
+    changed = False
+    for key in data:
+        if key not in data2 or data2[key] != data[key]:
+            bb.msg.debug(1, bb.msg.domain.Fetcher, "%s changed" % key)
+            changed = True
+            return True
+        else:
+            bb.msg.debug(2, bb.msg.domain.Fetcher, "%s did not change" % key)
+    return False
+
 # Function call order is usually:
 #   1. init
 #   2. go