#331: coalesce empty strings to null, to trigger the right authentication behavior from CLI

Author: bbottema

Diff for: modules/core-module/src/main/java/org/simplejavamail/internal/util/MiscUtil.java

@@ -71,6 +71,11 @@ public static <T> boolean valueNullOrEmpty(final @Nullable T value) {
 				(value instanceof byte[] && ((byte[]) value).length == 0);
 	}
 
+	@Nullable
+	public static <T> T emptyAsNull(final @Nullable T value) {
+		return valueNullOrEmpty(value) ? null : value;
+	}
+
 	public static String buildLogStringForSOCKSCommunication(final byte[] bytes, final boolean isReceived) {
 		final StringBuilder debugMsg = new StringBuilder();
 		debugMsg.append(isReceived ? "Received: " : "Sent: ");

Diff for: modules/simple-java-mail/src/main/java/org/simplejavamail/mailer/internal/MailerRegularBuilderImpl.java

@@ -19,6 +19,7 @@
 import static org.simplejavamail.config.ConfigLoader.Property.TRANSPORT_STRATEGY;
 import static org.simplejavamail.config.ConfigLoader.hasProperty;
 import static org.simplejavamail.internal.util.MiscUtil.checkArgumentNotEmpty;
+import static org.simplejavamail.internal.util.MiscUtil.emptyAsNull;
 import static org.simplejavamail.internal.util.Preconditions.verifyNonnullOrEmpty;
 
 /**
@@ -109,8 +110,8 @@ public MailerRegularBuilderImpl withTransportStrategy(@NotNull final TransportSt
 	public MailerRegularBuilderImpl withSMTPServer(@Nullable final String host, @Nullable final Integer port, @Nullable final String username, @Nullable final String password) {
 		return withSMTPServerHost(host)
 				.withSMTPServerPort(port)
-				.withSMTPServerUsername(username)
-				.withSMTPServerPassword(password);
+				.withSMTPServerUsername(emptyAsNull(username))
+				.withSMTPServerPassword(emptyAsNull(password));
 	}
 
 	/**