From 78faea80583e6fc903bdb8c146e8ff499b60c307 Mon Sep 17 00:00:00 2001
From: AlexGeller1 <87009702+AlexGeller1@users.noreply.github.com>
Date: Fri, 6 May 2022 01:01:14 +0200
Subject: [PATCH] Prevent encoding of the empty string for PDF417 (#1523)

* Added code so that the PDF417 encoder throws an exception when attempting to encode the empty string
---
 .../google/zxing/pdf417/encoder/PDF417HighLevelEncoder.java | 4 ++++
 .../google/zxing/pdf417/encoder/PDF417EncoderTestCase.java  | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417HighLevelEncoder.java b/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417HighLevelEncoder.java
index 79226e060..282cc7377 100644
--- a/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417HighLevelEncoder.java
+++ b/core/src/main/java/com/google/zxing/pdf417/encoder/PDF417HighLevelEncoder.java
@@ -171,6 +171,10 @@ final class PDF417HighLevelEncoder {
   static String encodeHighLevel(String msg, Compaction compaction, Charset encoding, boolean autoECI) 
       throws WriterException {
 
+    if (msg.isEmpty()) {
+      throw new WriterException("Empty message not allowed");
+    }
+
     if (encoding == null && !autoECI) {
       for (int i = 0; i < msg.length(); i++) {
         if (msg.charAt(i) > 255) {
diff --git a/core/src/test/java/com/google/zxing/pdf417/encoder/PDF417EncoderTestCase.java b/core/src/test/java/com/google/zxing/pdf417/encoder/PDF417EncoderTestCase.java
index 8166333ed..f0c9aa5ab 100644
--- a/core/src/test/java/com/google/zxing/pdf417/encoder/PDF417EncoderTestCase.java
+++ b/core/src/test/java/com/google/zxing/pdf417/encoder/PDF417EncoderTestCase.java
@@ -16,6 +16,8 @@
 
 package com.google.zxing.pdf417.encoder;
 
+import com.google.zxing.WriterException;
+
 import java.nio.charset.StandardCharsets;
 
 import org.junit.Assert;
@@ -67,4 +69,8 @@ public final class PDF417EncoderTestCase extends Assert {
     assertEquals("\u039f\u001A\u0385abcd", encoded);
   }
 
+  @Test(expected = WriterException.class)
+  public void testEncodeEmptyString() throws Exception {
+    PDF417HighLevelEncoder.encodeHighLevel("", Compaction.AUTO, null, false);
+  }
 }