fixed RecordFormatException when reading unicode strings with photenic data, see Bugzilla 50779

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1080496 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/status.xml

@@ -34,6 +34,7 @@
 
     <changes>
         <release version="3.8-beta2" date="2011-??-??">
+           <action dev="poi-developers" type="fix">50779 - fixed RecordFormatException when reading unicode strings with photenic data</action>
            <action dev="poi-developers" type="fix">50718 - More helpful error message when you try to create a CellReference with #REF!</action>
            <action dev="poi-developers" type="fix">50784 - XSSFColors return by XSSFFont now have theme information applied to them</action>
            <action dev="poi-developers" type="fix">50846 - Improve how XSSFColor inherits from Themes</action>

src/java/org/apache/poi/hssf/record/common/UnicodeString.java

@@ -22,6 +22,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
+import org.apache.poi.hssf.record.cont.ContinuableRecordInput;
 import org.apache.poi.hssf.record.RecordInputStream;
 import org.apache.poi.hssf.record.cont.ContinuableRecordOutput;
 import org.apache.poi.util.BitField;
@@ -435,7 +436,7 @@ public class UnicodeString implements Comparable<UnicodeString> { // TODO - make
         }
 
         if (isExtendedText() && (extensionLength > 0)) {
-          field_5_ext_rst = new ExtRst(in, extensionLength);
+          field_5_ext_rst = new ExtRst(new ContinuableRecordInput(in), extensionLength);
           if(field_5_ext_rst.getDataSize()+4 != extensionLength) {
              System.err.println("ExtRst was supposed to be " + extensionLength + " bytes long, but seems to actually be " + (field_5_ext_rst.getDataSize()+4));
           }

src/java/org/apache/poi/hssf/record/cont/ContinuableRecordInput.java

@@ -0,0 +1,118 @@
+/*
+ *  ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ====================================================================
+ */
+
+package org.apache.poi.hssf.record.cont;
+
+import org.apache.poi.hssf.record.RecordInputStream;
+import org.apache.poi.hssf.record.ContinueRecord;
+import org.apache.poi.util.LittleEndianInput;
+
+/**
+ * A decorated {@link RecordInputStream} that can read primitive data types
+ * (short, int, long, etc.) spanned across a {@link ContinueRecord } boundary.
+ *
+ * <p>
+ *  Most records construct themselves from {@link RecordInputStream}.
+ *  This class assumes that a {@link ContinueRecord} record break always occurs at the type boundary,
+ *  however, it is not always so.
+ * </p>
+ *  Two  attachments to <a href="https://issues.apache.org/bugzilla/show_bug.cgi?id=50779">Bugzilla 50779</a>
+ *  demonstrate that a CONTINUE break can appear right in between two bytes of a unicode character
+ *  or between two bytes of a <code>short</code>. The problematic portion of the data is
+ *  in a Asian Phonetic Settings Block (ExtRst) of a UnicodeString.
+ * <p>
+ *  {@link RecordInputStream} greedily requests the bytes to be read and stumbles on such files with a
+ *  "Not enough data (1) to read requested (2) bytes" exception.  The <code>ContinuableRecordInput</code>
+ *   class circumvents this "type boundary" rule and reads data byte-by-byte rolling over CONTINUE if necessary.
+ * </p>
+ *
+ * <p>
+ * YK: For now (March 2011) this class is only used to read
+ *   @link org.apache.poi.hssf.record.common.UnicodeString.ExtRst} blocks of a UnicodeString.
+ *
+ * </p>
+ *
+ * @author Yegor Kozlov
+ */
+public class ContinuableRecordInput implements LittleEndianInput {
+    private final RecordInputStream _in;
+
+    public ContinuableRecordInput(RecordInputStream in){
+        _in = in;
+    }
+    public int available(){
+        return _in.available();
+    }
+
+    public byte readByte(){
+        return _in.readByte();
+    }
+
+    public int readUByte(){
+        return _in.readUByte();
+    }
+
+    public short readShort(){
+        return _in.readShort();
+    }
+
+    public int readUShort(){
+        int ch1 = readUByte();
+        int ch2 = readUByte();
+        return (ch2 << 8) + (ch1 << 0);
+    }
+
+    public int readInt(){
+        int ch1 = _in.readUByte();
+        int ch2 = _in.readUByte();
+        int ch3 = _in.readUByte();
+        int ch4 = _in.readUByte();
+        return (ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0);
+    }
+
+    public long readLong(){
+        int b0 = _in.readUByte();
+        int b1 = _in.readUByte();
+        int b2 = _in.readUByte();
+        int b3 = _in.readUByte();
+        int b4 = _in.readUByte();
+        int b5 = _in.readUByte();
+        int b6 = _in.readUByte();
+        int b7 = _in.readUByte();
+        return (((long)b7 << 56) +
+                ((long)b6 << 48) +
+                ((long)b5 << 40) +
+                ((long)b4 << 32) +
+                ((long)b3 << 24) +
+                (b2 << 16) +
+                (b1 <<  8) +
+                (b0 <<  0));
+    }
+
+    public double readDouble(){
+        return _in.readDouble();
+    }
+    public void readFully(byte[] buf){
+        _in.readFully(buf);
+    }
+    public void readFully(byte[] buf, int off, int len){
+        _in.readFully(buf, off, len);
+    }
+
+}

src/testcases/org/apache/poi/hssf/usermodel/TestBugs.java

@@ -2019,4 +2019,13 @@ if(1==2) {
        
        // TODO Identify what excel doesn't like, and check for that
     }
+
+    public void test50779() throws Exception {
+       HSSFWorkbook wb1 = openSample("50779_1.xls");
+       writeOutAndReadBack(wb1);
+
+        HSSFWorkbook wb2 = openSample("50779_2.xls");
+        writeOutAndReadBack(wb2);
+    }
+
 }