[patch #2951] FileChannelImpl read/write(buff, offset, length) fails when buff.length == 0

[Mark Wielaard]

This mail is an automated notification from the patch tracker
 of the project: classpath.

/**************************************************************************/
[patch #2951] Latest Modifications:

Changes by: 
                Mark Wielaard <address@hidden>
'Date: 
                Thu 04/29/04 at 21:51 (Europe/Amsterdam)

            What     | Removed                   | Added
---------------------------------------------------------------------------
          Resolution | None                      | Fixed
         Assigned to | None                      | mark
              Status | Open                      | Closed


------------------ Additional Follow-up Comments ----------------------------
Thanks. I committed a somewhat similar fix which also fixes another issue with 
read(byte[]).

2004-04-29  Stephen Crawley  <address@hidden>
            Mark Wielaard  <address@hidden>
 
        * native/jni/java-nio/gnu_java_nio_channels_FileChannelImpl.c
        (Java_gnu_java_nio_channels_FileChannelImpl_read___3BII):
        Fill buffer with a  do-while bytes_read < 1 loop.
        Check for length == 0.







/**************************************************************************/
[patch #2951] Full Item Snapshot:

URL: <http://savannah.gnu.org/patch/?func=detailitem&item_id=2951>
Project: classpath
Submitted by: Stephen Crawley
On: Mon 04/19/04 at 15:27

Category:  None
Priority:  5 - Normal
Resolution:  Fixed
Assigned to:  mark
Originator Email:  
Status:  Closed


Summary:  FileChannelImpl read/write(buff, offset, length) fails when 
buff.length == 0

Original Submission:  The current native implementation of the 3 argument read 
and write methods of gnu.java.nio.channel.FileChannelImpl
throw an IOException with message "Unexpected JNI error"
when the buff argument has zero length.  This can happen
if an application tries to read or write an zero length
byte array with a File{Input,Output}Stream.  The problem
is that the native methods don't check the length arg
before making the JNI GetByteArrayElements call.  The
latter call then fails ...

The bugs are exercised by these Mauve testcases:
  gnu.testlet.java.io.FileOutputStream.write
  gnu.testlet.java.io.FileInputStream.read

The obvious fix is to have the native methods test for
length == 0 explicitly.  Suggested ChangeLog entries:

2004-04-20 Stephen Crawley <address@hidden>
  * native/jni/java-nio/gnu_java_nio_channels_FileChannelImpl.c 
(Java_gnu_java_nio_channels_FileChannelImpl_read___3BII) :
  check for length == 0
  *  native/jni/java-nio/gnu_java_nio_channels_FileChannelImpl.c 
(Java_gnu_java_nio_channels_FileChannelImpl_write___3BII)
  ditto





Follow-up Comments
------------------


-------------------------------------------------------
Date: Thu 04/29/04 at 21:51         By: mark
Thanks. I committed a somewhat similar fix which also fixes another issue with 
read(byte[]).

2004-04-29  Stephen Crawley  <address@hidden>
            Mark Wielaard  <address@hidden>
 
        * native/jni/java-nio/gnu_java_nio_channels_FileChannelImpl.c
        (Java_gnu_java_nio_channels_FileChannelImpl_read___3BII):
        Fill buffer with a  do-while bytes_read < 1 loop.
        Check for length == 0.







File Attachments
-------------------

-------------------------------------------------------
Date: Mon 04/19/04 at 15:27  Name: diffs  Size: 1KB   By: crawley

http://savannah.gnu.org/patch/download.php?item_id=2951&amp;item_file_id=3124






For detailed info, follow this link:
<http://savannah.gnu.org/patch/?func=detailitem&item_id=2951>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/