Expose the filter blob limit in UploadPack

Similar to UploadPack.getDepth() to know the shallow clone depth, expose
the user-specified filter blob limit for partial clones.

Change-Id: I04bde06862a1cf8a9862d950c15023c49d16a2a6
Signed-off-by: Terry Parker <tparker@google.com>

org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java

@@ -1525,6 +1525,20 @@ public class UploadPack {
 		return currentRequest.getDepth();
 	}
 
+	/**
+	 * Returns the filter blob limit for the current request. Valid only after
+	 * calling recvWants(). A limit -1 means no limit.
+	 *
+	 * @return filter blob limit requested by the client, or -1 if no limit
+	 * @since 5.3
+	 */
+	public long getFilterBlobLimit() {
+		if (currentRequest == null) {
+			throw new RequestNotYetReadException();
+		}
+		return currentRequest.getFilterBlobLimit();
+	}
+
 	/**
 	 * Get the user agent of the client.
 	 * <p>