Fix bug of incrementing counter in PdfTokenizer#decodeStringContent in case of ending line on octal number

DEVSIX-7476

Author: introfog

io/src/main/java/com/itextpdf/io/source/PdfTokenizer.java

@@ -22,15 +22,15 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.io.source;
 
+import com.itextpdf.commons.utils.MessageFormatUtil;
 import com.itextpdf.io.exceptions.IOException;
 import com.itextpdf.io.exceptions.IoExceptionMessageConstant;
 import com.itextpdf.io.logs.IoLogMessageConstant;
-import com.itextpdf.commons.utils.MessageFormatUtil;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.io.Closeable;
 import java.util.Arrays;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class PdfTokenizer implements Closeable {
 
@@ -525,7 +525,8 @@ protected static byte[] decodeStringContent(byte[] content, int from, int to, bo
 
         // <6954657874ae...>
         if (hexWriting) {
-            for (int i = from; i <= to; ) {
+            int i = from;
+            while (i <= to) {
                 int v1 = ByteBuffer.getHex(content[i++]);
                 if (i > to) {
                     buffer.append(v1 << 4);
@@ -537,8 +538,8 @@ protected static byte[] decodeStringContent(byte[] content, int from, int to, bo
             }
         } else {
             // ((iText\( some version)...)
-
-            for (int i = from; i <= to; ) {
+            int i = from;
+            while (i <= to) {
                 int ch = content[i++];
                 if (ch == '\\') {
                     boolean lineBreak = false;
@@ -577,19 +578,17 @@ protected static byte[] decodeStringContent(byte[] content, int from, int to, bo
                                 break;
                             }
                             int octal = ch - '0';
-                            ch = content[i++];
-                            if (ch < '0' || ch > '7') {
-                                i--;
+                            if (i > to) {
                                 ch = octal;
                                 break;
                             }
-                            octal = (octal << 3) + ch - '0';
                             ch = content[i++];
-                            if (ch < '0' || ch > '7') {
-                                i--;
+                            octal = (octal << 3) + ch - '0';
+                            if (ch < '0' || ch > '7' || i > to) {
                                 ch = octal;
                                 break;
                             }
+                            ch = content[i++];
                             octal = (octal << 3) + ch - '0';
                             ch = octal & 0xff;
                             break;

io/src/test/java/com/itextpdf/io/source/PdfTokenizerTest.java

@@ -22,8 +22,8 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.io.source;
 
-import com.itextpdf.io.source.PdfTokenizer.TokenType;
 import com.itextpdf.commons.utils.MessageFormatUtil;
+import com.itextpdf.io.source.PdfTokenizer.TokenType;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.UnitTest;
 
@@ -439,6 +439,30 @@ public void primitivesTest() throws Exception {
         Assert.assertEquals("-116.23", new String(tok.getByteContent()));
     }
 
+    @Test
+    public void octalNumberLong1Test() {
+        // 49 equal to string "1", octal 1 equals to 1 in decimal
+        byte[] bytes = new byte[] {92, 49};
+        byte[] result = PdfTokenizer.decodeStringContent(bytes, false);
+        Assert.assertArrayEquals(new byte[] {1}, result);
+    }
+
+    @Test
+    public void octalNumberLong2Test() {
+        // 49 50 equal to string "12", octal 12 equals to 10 in decimal
+        byte[] bytes = new byte[] {92, 49, 50};
+        byte[] result = PdfTokenizer.decodeStringContent(bytes, false);
+        Assert.assertArrayEquals(new byte[] {10}, result);
+    }
+
+    @Test
+    public void octalNumberLong3Test() {
+        // 49 50 51 equal to string "123", octal 123 equals to 83 in decimal
+        byte[] bytes = new byte[] {92, 49, 50, 51};
+        byte[] result = PdfTokenizer.decodeStringContent(bytes, false);
+        Assert.assertArrayEquals(new byte[] {83}, result);
+    }
+
     private void checkTokenTypes(String data, TokenType... expectedTypes) throws Exception {
         RandomAccessSourceFactory factory = new RandomAccessSourceFactory();
         PdfTokenizer tok = new PdfTokenizer(new RandomAccessFileOrArray(factory