Ensure RawText closes the FileInputStream when read is complete

Rather than implementing the file reading logic ourselves, and
wind up leaking the FileInputStream's file descriptor until the
next GC, use IO.readFully(File) which wraps the read loop inside
of a try/finally to ensure the stream is closed before it exits.

Change-Id: I85a3fe87d5eff88fa788962004aebe19d2e91bb4
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Roland Grunberg <rgrunber@redhat.com>

org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java

 package org.eclipse.jgit.diff;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 
+import org.eclipse.jgit.util.IO;
 import org.eclipse.jgit.util.IntList;
 import org.eclipse.jgit.util.RawParseUtils;
 
 	 * @throws IOException if Exceptions occur while reading the file
 	 */
 	public RawText(File file) throws IOException {
-		this(readFile(file));
+		this(IO.readFully(file));
 	}
 
 	public int size() {
 			hash = (hash << 5) ^ (raw[ptr] & 0xff);
 		return hash;
 	}
-
-	private static byte[] readFile(File file) throws IOException {
-		byte[] result = new byte[(int)file.length()];
-		FileInputStream in = new FileInputStream(file);
-		for (int off = 0; off < result.length; ) {
-			int read = in.read(result, off, result.length - off);
-			if (read < 0)
-				throw new IOException("Early EOF");
-			off += read;
-		}
-		return result;
-	}
 }