Fix for bug 46545 - ObjRecord should ignore excessive padding written by previous POI versions

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@738709 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 59 insertions, 10 deletions

diff --git a/src/testcases/org/apache/poi/hssf/record/TestSubRecord.java b/src/testcases/org/apache/poi/hssf/record/TestSubRecord.java
index 9d0edd1c14..926f243975 100644
--- a/src/testcases/org/apache/poi/hssf/record/TestSubRecord.java
+++ b/src/testcases/org/apache/poi/hssf/record/TestSubRecord.java
@@ -25,6 +25,7 @@ import junit.framework.AssertionFailedError;
 import junit.framework.TestCase;
 
 import org.apache.poi.util.HexRead;
+import org.apache.poi.util.LittleEndian;
 
 /**
  * Tests Subrecord components of an OBJ record.  Test data taken directly
@@ -85,21 +86,21 @@ public final class TestSubRecord extends TestCase {
 	
 	public void testReadManualComboWithFormula() {
 		byte[] data = HexRead.readFromString(""
-   			+ "5D 00 66 00 "
-   			+ "15 00 12 00 14 00 02 00 11 20 00 00 00 00 "
-   			+ "20 44 C6 04 00 00 00 00 0C 00 14 00 04 F0 C6 04 "
-   			+ "00 00 00 00 00 00 01 00 06 00 00 00 10 00 00 00 "
-   			+ "0E 00 0C 00 05 00 80 44 C6 04 24 09 00 02 00 02 "
-   			+ "13 00 DE 1F 10 00 09 00 80 44 C6 04 25 0A 00 0F "
-   			+ "00 02 00 02 00 02 06 00 03 00 08 00 00 00 00 00 "
-   			+ "08 00 00 00 00 00 00 00 " // TODO sometimes last byte is non-zero
-   		);
+			+ "5D 00 66 00 "
+			+ "15 00 12 00 14 00 02 00 11 20 00 00 00 00 "
+			+ "20 44 C6 04 00 00 00 00 0C 00 14 00 04 F0 C6 04 "
+			+ "00 00 00 00 00 00 01 00 06 00 00 00 10 00 00 00 "
+			+ "0E 00 0C 00 05 00 80 44 C6 04 24 09 00 02 00 02 "
+			+ "13 00 DE 1F 10 00 09 00 80 44 C6 04 25 0A 00 0F "
+			+ "00 02 00 02 00 02 06 00 03 00 08 00 00 00 00 00 "
+			+ "08 00 00 00 00 00 00 00 " // TODO sometimes last byte is non-zero
+		);
 		
 		RecordInputStream in = TestcaseRecordInputStream.create(data);
 		ObjRecord or = new ObjRecord(in);
 		byte[] data2 = or.serialize();
 		if (data2.length == 8228) {
-			throw new AssertionFailedError("Identified bug XXXXX");
+			throw new AssertionFailedError("Identified bug 45778");
 		}
 		assertEquals("Encoded length", data.length, data2.length);
 		for (int i = 0; i < data.length; i++) {
@@ -109,4 +110,52 @@ public final class TestSubRecord extends TestCase {
 		}
 		assertTrue(Arrays.equals(data, data2));
 	}
+
+	/**
+	 * Some versions of POI (e.g. 3.1 - prior to svn r707450 / bug 45778) interpreted the ftLbs 
+	 * subrecord second short (0x1FEE) as a length, and hence read lots of extra padding.  This 
+	 * buffer-overrun in {@link RecordInputStream} happened silently due to problems later fixed
+	 * in svn 707778. When the ObjRecord is written, the extra padding is written too, making the 
+	 * record 8224 bytes long instead of 70.  
+	 * (An aside: It seems more than a coincidence that this problem creates a record of exactly
+	 * {@link RecordInputStream#MAX_RECORD_DATA_SIZE} but not enough is understood about 
+	 * subrecords to explain this.)<br/>
+	 * 
+	 * Excel reads files with this excessive padding OK.  It also truncates the over-sized
+	 * ObjRecord back to the proper size.  POI should do the same.
+	 */
+	public void testWayTooMuchPadding_bug46545() {
+		byte[] data = HexRead.readFromString(""
+			+ "15 00 12 00 14 00 13 00 01 21 00 00 00"
+			+ "00 98 0B 5B 09 00 00 00 00 0C 00 14 00 00 00 00 00 00 00 00"
+			+ "00 00 00 01 00 01 00 00 00 10 00 00 00 "
+			// ftLbs
+			+ "13 00 EE 1F 00 00 "
+			+ "01 00 00 00 01 06 00 00 02 00 08 00 75 00 "
+			// ftEnd
+			+ "00 00 00 00"
+		);
+		final int LBS_START_POS = 0x002E;
+		final int WRONG_LBS_SIZE = 0x1FEE;
+		assertEquals(0x0013, LittleEndian.getShort(data, LBS_START_POS+0));
+		assertEquals(WRONG_LBS_SIZE, LittleEndian.getShort(data, LBS_START_POS+2));
+		int wrongTotalSize = LBS_START_POS + 4 + WRONG_LBS_SIZE;
+		byte[] wrongData = new byte[wrongTotalSize];
+		System.arraycopy(data, 0, wrongData, 0, data.length);
+		// wrongData has the ObjRecord data as would have been written by v3.1 
+		
+		RecordInputStream in = TestcaseRecordInputStream.create(ObjRecord.sid, wrongData);
+		ObjRecord or;
+		try {
+			or = new ObjRecord(in);
+		} catch (RecordFormatException e) {
+			if (e.getMessage().startsWith("Leftover 8154 bytes in subrecord data")) {
+				throw new AssertionFailedError("Identified bug 46545");
+			}
+			throw e;
+		}
+		// make sure POI properly truncates the ObjRecord data
+		byte[] data2 = or.serialize();
+		TestcaseRecordInputStream.confirmRecordEncoding(ObjRecord.sid, data, data2);
+	}
 }