Merge "Add extend-project tag to support adding groups to an existing project"

docs/manifest-format.txt

@@ -26,6 +26,7 @@ following DTD:
                         manifest-server?,
                         remove-project*,
                         project*,
+                        extend-project*,
                         repo-hooks?)>
 
     <!ELEMENT notice (#PCDATA)>
@@ -67,6 +68,11 @@ following DTD:
     <!ATTLIST annotation value CDATA #REQUIRED>
     <!ATTLIST annotation keep  CDATA "true">
 
+    <!ELEMENT extend-project>
+    <!ATTLIST extend-project name CDATA #REQUIRED>
+    <!ATTLIST extend-project path CDATA #IMPLIED>
+    <!ATTLIST extend-project groups CDATA #IMPLIED>
+
     <!ELEMENT remove-project (EMPTY)>
     <!ATTLIST remove-project name  CDATA #REQUIRED>
 
@@ -252,6 +258,22 @@ rather than the `name` attribute.  This attribute only applies to the
 local mirrors syncing, it will be ignored when syncing the projects in a
 client working directory.
 
+Element extend-project
+----------------------
+
+Modify the attributes of the named project.
+
+This element is mostly useful in a local manifest file, to modify the
+attributes of an existing project without completely replacing the
+existing project definition.  This makes the local manifest more robust
+against changes to the original manifest.
+
+Attribute `path`: If specified, limit the change to projects checked out
+at the specified path, rather than all projects with the given name.
+
+Attribute `groups`: List of additional groups to which this project
+belongs.  Same syntax as the corresponding element of `project`.
+
 Element annotation
 ------------------