PushCertificateParser: Add fromString method

Change-Id: I74c3f65a9ff297f708d996a4c138456a31a466b8

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PushCertificateParserTest.java

@@ -55,6 +55,7 @@ import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
+import java.io.StringReader;
 
 import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
@@ -280,9 +281,7 @@ public class PushCertificateParserTest {
 
 	@Test
 	public void testParseReader() throws Exception {
-		Reader reader = new InputStreamReader(
+		Reader reader = new StringReader(concatPacketLines(INPUT, 0, 18));
-				new ByteArrayInputStream(
-						Constants.encode(concatPacketLines(INPUT, 0, 18))));
 		PushCertificate streamCert = PushCertificateParser.fromReader(reader);
 
 		PacketLineIn pckIn = newPacketLineIn(INPUT);
@@ -320,6 +319,14 @@ public class PushCertificateParserTest {
 		assertEquals(pckCmd.getNewId().name(), streamCmd.getNewId().name());
 	}
 
+	@Test
+	public void testParseString() throws Exception {
+		String str = concatPacketLines(INPUT, 0, 18);
+		assertEquals(
+				PushCertificateParser.fromReader(new StringReader(str)),
+				PushCertificateParser.fromString(str));
+	}
+
 	@Test
 	public void testParseMultipleFromStream() throws Exception {
 		String input = concatPacketLines(INPUT, 0, 17);

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

@@ -156,6 +156,24 @@ public class PushCertificateParser {
 		return new PushCertificateParser().parse(r);
 	}
 
+	/**
+	 * Parse a push certificate from a string.
+	 *
+	 * @see #fromReader(Reader)
+	 * @param str
+	 *            input string.
+	 * @return the parsed certificate.
+	 * @throws PackProtocolException
+	 *             if the certificate is malformed.
+	 * @throws IOException
+	 *             if there was an error reading from the input.
+	 * @since 4.1
+	 */
+	public static PushCertificate fromString(String str)
+			throws PackProtocolException, IOException {
+		return fromReader(new java.io.StringReader(str));
+	}
+
 	private boolean received;
 	private String version;
 	private PushCertificateIdent pusher;