Quick fix for unsupported OpenType gdef class.

SUP-2076

Author: pavel-alay

io/src/main/java/com/itextpdf/io/LogMessageConstant.java

@@ -113,4 +113,5 @@ public final class LogMessageConstant {
     public static final String WRITER_ENCRYPTION_IS_IGNORED_APPEND = "Writer encryption will be ignored, because append mode is used. Document will preserve the original encryption (or will stay unencrypted)";
     public static final String WRITER_ENCRYPTION_IS_IGNORED_PRESERVE = "Writer encryption will be ignored, because preservation of encryption is enabled. Document will preserve the original encryption (or will stay unencrypted)";
     public static final String XREF_ERROR = "Error occurred while reading cross reference table. Cross reference table will be rebuilt.";
+    public static final String OPENTYPE_GDEF_TABLE_ERROR = "OpenType GDEF table error: {0}";
 }

io/src/main/java/com/itextpdf/io/font/otf/OpenTypeFontTableReader.java

@@ -188,7 +188,7 @@ protected abstract OpenTableLookup readLookupTable(int lookupType, int lookupFla
 			throws java.io.IOException;
 
     protected final OtfClass readClassDefinition(int classLocation) throws java.io.IOException {
-        return new OtfClass(rf, classLocation);
+        return OtfClass.create(rf, classLocation);
     }
 
     protected final int[] readUShortArray(int size, int location) throws java.io.IOException {

io/src/main/java/com/itextpdf/io/font/otf/OpenTypeGdefTableReader.java

@@ -73,10 +73,10 @@ public void readTable() throws java.io.IOException {
             rf.readUnsignedShort(); //skip Ligature Caret List Table
             int markAttachClassDefOffset = rf.readUnsignedShort();
             if (glyphClassDefOffset > 0) {
-                glyphClass = new OtfClass(rf, glyphClassDefOffset + tableLocation);
+                glyphClass = OtfClass.create(rf, glyphClassDefOffset + tableLocation);
             }
             if (markAttachClassDefOffset > 0) {
-                markAttachmentClass = new OtfClass(rf, markAttachClassDefOffset + tableLocation);
+                markAttachmentClass = OtfClass.create(rf, markAttachClassDefOffset + tableLocation);
             }
         }
     }

io/src/main/java/com/itextpdf/io/font/otf/OtfClass.java

@@ -43,9 +43,13 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.io.font.otf;
 
+import com.itextpdf.io.LogMessageConstant;
 import com.itextpdf.io.util.IntHashtable;
 import com.itextpdf.io.source.RandomAccessFileOrArray;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
 import java.io.Serializable;
 
 public class OtfClass implements Serializable {
@@ -57,7 +61,11 @@ public class OtfClass implements Serializable {
 
     //key is glyph, value is class inside all 2
     private IntHashtable mapClass = new IntHashtable();
-    
+
+    /**
+     * @deprecated use {@link #create(RandomAccessFileOrArray, int)} instead.
+     */
+    @Deprecated
     public OtfClass(RandomAccessFileOrArray rf, int classLocation) throws java.io.IOException {
         rf.seek(classLocation);
         int classFormat = rf.readUnsignedShort();
@@ -83,6 +91,18 @@ public OtfClass(RandomAccessFileOrArray rf, int classLocation) throws java.io.IO
             throw new java.io.IOException("Invalid class format " + classFormat);
         }
     }
+
+    public static OtfClass create(RandomAccessFileOrArray rf, int classLocation) {
+        OtfClass otfClass;
+        try {
+            otfClass = new OtfClass(rf, classLocation);
+        } catch (IOException e) {
+            Logger logger = LoggerFactory.getLogger(OtfClass.class);
+            logger.error(LogMessageConstant.OPENTYPE_GDEF_TABLE_ERROR);
+            otfClass = null;
+        }
+        return otfClass;
+    }
 
     public int getOtfClass(int glyph) {
         return mapClass.get(glyph);