Base class for "old version" exceptions, and new HSLF detection + use of old versions exception

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@775526 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/changes.xml

@@ -37,6 +37,7 @@
 
 		<!-- Don't forget to update status.xml too! -->
         <release version="3.5-beta6" date="2009-??-??">
+           <action dev="POI-DEVELOPERS" type="add">41711 - Base class for "old version" exceptions, and new HSLF detection + use of old versions exception</action>
            <action dev="POI-DEVELOPERS" type="fix">47179 - Fix string encoding issues with HSMF chunks on non-windows platforms</action>
            <action dev="POI-DEVELOPERS" type="add">47183 - Attachment support for HSMF</action>
            <action dev="POI-DEVELOPERS" type="fix">47154 - Handle the cell format @ as the same as General</action>

src/documentation/content/xdocs/status.xml

@@ -34,6 +34,7 @@
 	<!-- Don't forget to update changes.xml too! -->
     <changes>
         <release version="3.5-beta6" date="2009-??-??">
+           <action dev="POI-DEVELOPERS" type="add">41711 - Base class for "old version" exceptions, and new HSLF detection + use of old versions exception</action>
            <action dev="POI-DEVELOPERS" type="fix">47179 - Fix string encoding issues with HSMF chunks on non-windows platforms</action>
            <action dev="POI-DEVELOPERS" type="add">47183 - Attachment support for HSMF</action>
            <action dev="POI-DEVELOPERS" type="fix">47154 - Handle the cell format @ as the same as General</action>

src/java/org/apache/poi/OldFileFormatException.java

@@ -0,0 +1,27 @@
+/* ====================================================================
+   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;
+
+/**
+ * Base class of all the exceptions that POI throws in the event
+ * that it's given a file that's older than currently supported.
+ */
+public abstract class OldFileFormatException extends IllegalArgumentException {
+	public OldFileFormatException(String s) {
+		super(s);
+	}
+}

src/java/org/apache/poi/hssf/OldExcelFormatException.java

@@ -16,7 +16,9 @@
 ==================================================================== */
 package org.apache.poi.hssf;
 
-public class OldExcelFormatException extends IllegalArgumentException {
+import org.apache.poi.OldFileFormatException;
+
+public class OldExcelFormatException extends OldFileFormatException {
 	public OldExcelFormatException(String s) {
 		super(s);
 	}

src/scratchpad/src/org/apache/poi/hslf/exceptions/OldPowerPointFormatException.java

@@ -0,0 +1,30 @@
+
+/* ====================================================================
+   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.hslf.exceptions;
+
+import org.apache.poi.OldFileFormatException;
+
+/**
+ * This exception is thrown when we try to open a PowerPoint file, and
+ *  it's too old for us.
+ */
+public class OldPowerPointFormatException extends OldFileFormatException {
+	public OldPowerPointFormatException(String s) {
+		super(s);
+	}
+}

src/scratchpad/src/org/apache/poi/hslf/record/CurrentUserAtom.java

@@ -26,6 +26,7 @@ import org.apache.poi.util.LittleEndian;
 import org.apache.poi.util.StringUtil;
 import org.apache.poi.hslf.exceptions.CorruptPowerPointFileException;
 import org.apache.poi.hslf.exceptions.EncryptedPowerPointFileException;
+import org.apache.poi.hslf.exceptions.OldPowerPointFormatException;
 
 
 /**
@@ -110,18 +111,31 @@ public class CurrentUserAtom
 		// Decide how big it is
 		DocumentEntry docProps =
 			(DocumentEntry)dir.getEntry("Current User");
-		_contents = new byte[docProps.getSize()];
-
-		// Check it's big enough - if it's not at least 28 bytes long, then
-		//  the record is corrupt
-		if(_contents.length < 28) {
-			throw new CorruptPowerPointFileException("The Current User stream must be at least 28 bytes long, but was only " + _contents.length);
+		
+		// If it's clearly junk, bail out
+		if(docProps.getSize() > 131072) {
+			throw new CorruptPowerPointFileException("The Current User stream is implausably long. It's normally 28-200 bytes long, but was " + docProps.getSize() + " bytes");
 		}
-
+		
 		// Grab the contents
+		_contents = new byte[docProps.getSize()];
 		InputStream in = dir.createDocumentInputStream("Current User");
 		in.read(_contents);
 
+		// See how long it is. If it's under 28 bytes long, we can't
+		//  read it
+		if(_contents.length < 28) {
+			if(_contents.length >= 4) {
+				// PPT95 has 4 byte size, then data
+				int size = LittleEndian.getInt(_contents);
+				System.err.println(size);
+				if(size + 4 == _contents.length) {
+					throw new OldPowerPointFormatException("Based on the Current User stream, you seem to have supplied a PowerPoint95 file, which isn't supported");
+				}
+			}
+			throw new CorruptPowerPointFileException("The Current User stream must be at least 28 bytes long, but was only " + _contents.length);
+		}
+
 		// Set everything up
 		init();
 	}

src/scratchpad/testcases/org/apache/poi/hslf/model/TestSheet.java

@@ -43,6 +43,8 @@ public class TestSheet extends TestCase{
         File[] files = home.listFiles();
         for (int i = 0; i < files.length; i++) {
             if(!files[i].getName().endsWith(".ppt")) continue;
+            if(files[i].getName().endsWith("PPT95.ppt")) continue;
+            
             try {
                 FileInputStream is = new FileInputStream(files[i]);
                 HSLFSlideShow hslf = new HSLFSlideShow(is);

src/scratchpad/testcases/org/apache/poi/hslf/usermodel/TestBugs.java

@@ -19,6 +19,7 @@ package org.apache.poi.hslf.usermodel;
 
 import junit.framework.TestCase;
 import org.apache.poi.hslf.HSLFSlideShow;
+import org.apache.poi.hslf.exceptions.OldPowerPointFormatException;
 import org.apache.poi.hslf.model.*;
 import org.apache.poi.hslf.model.Shape;
 
@@ -380,4 +381,23 @@ public class TestBugs extends TestCase {
         assertEquals(1, run.length);
         assertEquals("Fundera, planera och involvera.", run[0].getText());
     }
+    
+    /**
+     * PowerPoint 95 files should throw a more helpful exception
+     * @throws Exception
+     */
+    public void test41711() throws Exception {
+    	// New file is fine
+        FileInputStream is = new FileInputStream(new File(cwd, "SampleShow.ppt"));
+        SlideShow ppt = new SlideShow(is);
+        
+        // PowerPoint 95 gives an old format exception
+        is = new FileInputStream(new File(cwd, "PPT95.ppt"));
+        try {
+        	new SlideShow(is);
+        	fail("OldPowerPointFormatException should've been thrown");
+        } catch(OldPowerPointFormatException e) {
+        	// Good
+        }
+    }
 }