Fixed the case where FastByteArrayOutputStream was throwing a RuntimeException for empty Strings

Author: torakiki

src/main/java/org/sejda/sambox/cos/PDFDocEncoding.java

@@ -144,7 +144,7 @@ public static String toString(byte[] bytes)
      */
     public static byte[] getBytes(String text)
     {
-        if (nonNull(text))
+        if (nonNull(text) && !text.isEmpty())
         {
             try (var out = new FastByteArrayOutputStream(text.length()))
             {

src/test/java/org/sejda/sambox/cos/PDFDocEncodingTest.java

@@ -93,7 +93,7 @@ public void testDeviations()
     }
 
     @Test
-    public void nullSafe() throws IOException
+    public void nullSafe()
     {
         var sb = new StringBuilder("Chuck");
         sb.append((char) 0x18);
@@ -103,6 +103,18 @@ public void nullSafe() throws IOException
         assertNull(PDFDocEncoding.getBytes(sb.toString()));
     }
 
+    @Test
+    public void nullText()
+    {
+        assertNull(PDFDocEncoding.getBytes(null));
+    }
+
+    @Test
+    public void blankSafe()
+    {
+        assertNull(PDFDocEncoding.getBytes(""));
+    }
+
     /**
      * PDFBOX-3864: Test that chars smaller than 256 which are NOT part of PDFDocEncoding are
      * handled correctly.