[jcifs] Bug in jCIFS 0.8.0 SmbFile.exists() method

[Michael Kerley]

I found a bug in the exists() method in jCIFS 0.8.0.  If I create an 
SmbFile representing a workgroup and call exists() on it, it always 
returns false (which is wrong).  However, if I create the file, call 
length(), and then call exists(), it returns true.  This problem only 
happens in version 0.8.0 (didn't test with 0.8.0b, but all 0.7.x 
versions seemed fine).  Also, the problem only seems to happen with 
domains.  If I call exists() on a server or a file, it works fine.

The following example is a modification of the Exists.java example 
program that comes with jCIFS.  I've also included sample output showing 
the bug (first using version 0.7.19, then using 0.8.0).

I hope this example helps solve the bug.  Keep up the good work.
Michael Kerley

------ BEGIN EXAMPLE CODE ------
import jcifs.smb.SmbFile;

public class Exists {
    public static void main( String argv[] ) throws Exception {
        System.out.println( "Method 1: call length() first" );
        exists1( argv[0] );

        System.out.println();
        System.out.println( "Method 2: do not call length() first" );
        exists2( argv[0] );
    }

    public static void exists1( String filename ) throws Exception {
        SmbFile f = new SmbFile( filename );
        System.out.println( f.length() + " bytes" ); // check the length 
first
        if( f.exists() ) {
            System.out.println( filename + " exists" );
        } else {
            System.out.println( filename + " does not exist" );
        }
    }

    public static void exists2( String filename ) throws Exception {
        SmbFile f = new SmbFile( filename );
        // don't check the length first
        if( f.exists() ) {
            System.out.println( filename + " exists" );
        } else {
            System.out.println( filename + " does not exist" );
        }
    }
}
------ END EXAMPLE CODE ------

------ BEGIN EXAMPLE OUTPUT ------
C:\java\jcifs_0.8.0\examples>set 
classpath=.;c:\java\jcifs_0.7.19\jcifs-0.7.19.jar

C:\java\jcifs_0.8.0\examples>java Exists smb://mydomain/
Method 1: call length() first
0 bytes
smb://mydomain/ exists

Method 2: do not call length() first
smb://mydomain/ exists

C:\java\jcifs_0.8.0\examples>set 
classpath=.;c:\java\jcifs_0.8.0\jcifs-0.8.0.jar

C:\java\jcifs_0.8.0\examples>java Exists smb://mydomain/
Method 1: call length() first
0 bytes
smb://mydomain/ exists

Method 2: do not call length() first
smb://mydomain/ does not exist
------ END EXAMPLE OUTPUT ------