[Bug libgcj/30600] New: gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[Bug libgcj/30600] New: gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[kaloian at doganov dot org]

Sometimes, gnu.gcj.convert.BytesToCharsetAdaptor's read method calls
inBuffer.limit(int) with a value that exceeds the buffer capacity.  This can be
easily reproduced when BytesToCharsetAdaptor is used with an input byte aray
that does not have to be decoded from the start, but from a greater possition
(inpos > 0). In this case the line inBuf.limit(inpos + inlength); leads to:

java.lang.IllegalArgumentException
   at java.nio.Buffer.limit(libgcj.so.7)
   at gnu.gcj.convert.BytesToCharsetAdaptor.read(libgcj.so.7)
   at java.lang.String.init(libgcj.so.7)
   at java.lang.String.<init>(libgcj.so.7)
   at BytesToCharsetAdaptorBug.main(BytesToCharsetAdaptorBug.java:6)

Please see the attached example.


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           Summary: gnu.gcj.convert.BytesToCharsetAdaptor calculates bad
                    argument for java.nio.Buffer.limit(int)
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcj
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kaloian at doganov dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[kaloian at doganov dot org]

------- Comment #1 from kaloian at doganov dot org  2007-01-26 17:15 -------
Created an attachment (id=12964)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12964&action=view)
Short test case that demonstrates the problem.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[kaloian at doganov dot org]

------- Comment #2 from kaloian at doganov dot org  2007-01-26 17:18 -------
(From update of attachment 12964)
The example works fine if you try to create the demo String using the whole
byte array. But if you wish to skip the fist byte this leads to
IllegalArgumentException because of the bad calculations in
BytesToCharsetAdaptor.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[kaloian at doganov dot org]

------- Comment #3 from kaloian at doganov dot org  2007-01-27 23:14 -------
Created an attachment (id=12971)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12971&action=view)
Trivial fix -- `inlenght' is the last valid index of the buffer, so it should
be used directly, without adding it to `inpos'.

It is stated in BytesToUnicode.read(char[],int,int) java docs:

"Note the asymmetry in that the input upper bound is inbuffer[inlength-1],
while the output upper bound is outbuffer[outpos+count-1]. The justification is
that inlength is like the count field of a BufferedInputStream, while the count
parameter is like the length parameter of a read request."

But obviously, in BytesToCharsetAdaptor's code `inlength' is not used according
to the note above.  Instead, it is expected `inlength' to contain a count,
which , when added to the value of `inpos', leads to the calculation of a
buffer limit greater than buffer's capacity (if `inpos' turns out to be greater
than zero).

This can be easily avoided by simply using `inlenght' in the way it is expected
to be used -- as an absolute index of array, not as a relative element count.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[tromey at gcc dot gnu dot org]

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tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-01-30 00:05:07
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[tromey at gcc dot gnu dot org]

------- Comment #4 from tromey at gcc dot gnu dot org  2007-01-30 02:47 -------
Subject: Bug 30600

Author: tromey
Date: Tue Jan 30 02:46:54 2007
New Revision: 121329

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=121329
Log:
2007-01-29  Kaloian Doganov  <kaloian@doganov.org>

        PR libgcj/30600:
        * gnu/gcj/convert/BytesToCharsetAdaptor.java (read): Fix call to
        'limit'.

Modified:
    trunk/libjava/ChangeLog
    trunk/libjava/classpath/lib/gnu/gcj/convert/BytesToCharsetAdaptor.class
    trunk/libjava/gnu/gcj/convert/BytesToCharsetAdaptor.java


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[tromey at gcc dot gnu dot org]

------- Comment #5 from tromey at gcc dot gnu dot org  2007-01-30 02:48 -------
Subject: Bug 30600

Author: tromey
Date: Tue Jan 30 02:48:26 2007
New Revision: 121330

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=121330
Log:
2007-01-29  Kaloian Doganov  <kaloian@doganov.org>

        PR libgcj/30600:
        * gnu/gcj/convert/BytesToCharsetAdaptor.java (read): Fix call to
        'limit'.

Modified:
    branches/redhat/gcc-4_1-branch-java-merge-20070117/libjava/ChangeLog
   
branches/redhat/gcc-4_1-branch-java-merge-20070117/libjava/gnu/gcj/convert/BytesToCharsetAdaptor.java


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[tromey at gcc dot gnu dot org]

------- Comment #6 from tromey at gcc dot gnu dot org  2007-01-30 03:06 -------
I put this into 4.2 and trunk.
Thanks!


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tromey at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600

[Bug libgcj/30600] gnu.gcj.convert.BytesToCharsetAdaptor calculates bad argument for java.nio.Buffer.limit(int)

[tromey at gcc dot gnu dot org]

------- Comment #7 from tromey at gcc dot gnu dot org  2007-01-30 03:08 -------
Subject: Bug 30600

Author: tromey
Date: Tue Jan 30 03:08:19 2007
New Revision: 121331

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=121331
Log:
2007-01-29  Kaloian Doganov  <kaloian@doganov.org>

        PR libgcj/30600:
        * gnu/gcj/convert/BytesToCharsetAdaptor.java (read): Fix call to
        'limit'.

Modified:
    branches/gcc-4_2-branch/libjava/ChangeLog
    branches/gcc-4_2-branch/libjava/gnu/gcj/convert/BytesToCharsetAdaptor.java


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30600