Fix bug #51832 - handle XLS files where the WRITEPROTECT record preceeds the FILEPASS one, rather than following as normal

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1172575 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/status.xml

 
     <changes>
         <release version="3.8-beta5" date="2011-??-??">
+           <action dev="poi-developers" type="fix">51832 - handle XLS files where the WRITEPROTECT record preceeds the FILEPASS one, rather than following as normal</action>
            <action dev="poi-developers" type="fix">51809 - correct GTE handling in COUNTIF</action>
            <action dev="poi-developers" type="add">Add HWPF API to update range text and delete bookmarks</action>
            <action dev="poi-developers" type="add">HWPF Bookmarks tables are correctly updated on text updates</action>

src/java/org/apache/poi/hssf/record/RecordFactoryInputStream.java

 			FilePassRecord fpr = null;
 			if (rec instanceof BOFRecord) {
 				_hasBOFRecord = true;
+				
+				// Fetch the next record, and see if it indicates whether
+				//  the document is encrypted or not
 				if (rs.hasNextRecord()) {
 					rs.nextRecord();
 					rec = RecordFactory.createSingleRecord(rs);
 					recSize += rec.getRecordSize();
 					outputRecs.add(rec);
+					
+					// Encrypted is normally BOF then FILEPASS
+					// May sometimes be BOF, WRITEPROTECT, FILEPASS
+					if (rec instanceof WriteProtectRecord && rs.hasNextRecord()) {
+	               rs.nextRecord();
+	               rec = RecordFactory.createSingleRecord(rs);
+	               recSize += rec.getRecordSize();
+	               outputRecs.add(rec);
+					}
+					
+					// If it's a FILEPASS, track it specifically but
+					//  don't include it in the main stream
 					if (rec instanceof FilePassRecord) {
 						fpr = (FilePassRecord) rec;
 						outputRecs.remove(outputRecs.size()-1);

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

 package org.apache.poi.hssf.usermodel;
 
 import junit.framework.AssertionFailedError;
+
+import org.apache.poi.EncryptedDocumentException;
 import org.apache.poi.hssf.HSSFITestDataProvider;
 import org.apache.poi.hssf.HSSFTestDataSamples;
 import org.apache.poi.hssf.OldExcelFormatException;
         writeOutAndReadBack(wb);
     }
 
+    /**
+     * Normally encrypted files have BOF then FILEPASS, but
+     *  some may squeeze a WRITEPROTECT in the middle
+     */
+    public void test51832() {
+       try {
+          openSample("51832.xls");
+          fail("Encrypted file");
+       } catch(EncryptedDocumentException e) {
+          // Good
+       }
+    }
 }