[partial] Don't pass --filter=blob:none for local checkouts.

Change-Id: I1479a5368041a161e653779a891573e0b167a5c1
Reviewed-on: https://fuchsia-review.googlesource.com/c/jiri/+/392326
Commit-Queue: Nathan Mulcahey <nmulcahey@google.com>
Reviewed-by: Haowei Wu <haowei@google.com>
diff --git a/project/operations.go b/project/operations.go
index 17275b6..d5a410e 100644
--- a/project/operations.go
+++ b/project/operations.go
@@ -144,7 +144,8 @@
 			// Shallow clones can not be used as as local git reference
 			opts = append(opts, gitutil.ReferenceOpt(cache))
 		}
-		if jirix.Partial {
+		// Passing --filter=blob:none for a local clone is a no-op.
+		if cache == r && jirix.Partial {
 			opts = append(opts, gitutil.OmitBlobsOpt(true))
 		}
 		if err = clone(jirix, r, op.destination, opts...); err != nil {