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From "Daniel Lowe (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (COMPRESS-189) ZipArchiveInputStream may read 0 bytes when reading from a nested Zip file
Date Wed, 10 Oct 2012 19:01:02 GMT

    [ https://issues.apache.org/jira/browse/COMPRESS-189?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13473473#comment-13473473
] 

Daniel Lowe commented on COMPRESS-189:
--------------------------------------

The bug is due to a bug in the implementation of ZipArchiveInputStream's readDeflated:

int read = 0;
try {
read = inf.inflate(buffer, start, length);
} catch (DataFormatException e) {
throw new ZipException(e.getMessage());
}
if (read == 0) {
if (inf.finished()) {
return -1;
} else if (buf.lengthOfLastRead == -1) {
throw new IOException("Truncated ZIP file");
}
}

can return 0
"A return value of 0 indicates that needsInput() or needsDictionary() should be called in
order to determine if more input data or a preset dictionary is required."

The assumedly correct implementation in InflaterInputStream:

int n;
while ((n = inf.inflate(b, off, len)) == 0) {
if (inf.finished() || inf.needsDictionary()) {
reachEOF = true;
return -1;
}
if (inf.needsInput()) {
fill();
}
}

calls the method in a while loop to avoid this problem.
                
> ZipArchiveInputStream may read 0 bytes when reading from a nested Zip file
> --------------------------------------------------------------------------
>
>                 Key: COMPRESS-189
>                 URL: https://issues.apache.org/jira/browse/COMPRESS-189
>             Project: Commons Compress
>          Issue Type: Bug
>          Components: Archivers
>    Affects Versions: 1.4.1
>         Environment: JDK 1.6 64-bit, Windows 7
>            Reporter: Daniel Lowe
>
> When the following code is run an error "Underlying input stream returned zero bytes"
is produced. If the commented line is uncommented it can be seen that the ZipArchiveInputStream
returned 0 bytes. This only happens the first time read is called, subsequent calls work as
expected i.e. the following code actually works correctly with that line uncommented!
> The zip file used to produce this behavious is available at http://wwmm.ch.cam.ac.uk/~dl387/test.ZIP
> If this is not the correct way of processing a zip file of zip files please let me know.
Also I believe whilst ZipFile can iterate over entries fast due to being able to look at the
master table whilst ZipArchiveInputStream cannot. Is there anyway of instantiating a ZipFile
from a zip file inside another zip file without first extracting the nested zip file?
>     ZipFile zipFile = new ZipFile("C:/test.ZIP");
>     for (Enumeration<ZipArchiveEntry> iterator = zipFile.getEntries(); iterator.hasMoreElements();
) {
>       ZipArchiveEntry entry = iterator.nextElement();
>       InputStream is = new BufferedInputStream(zipFile.getInputStream(entry));
>       ZipArchiveInputStream zipInput = new ZipArchiveInputStream(is);
>       ZipArchiveEntry innerEntry;
>       while ((innerEntry = zipInput.getNextZipEntry()) != null){
>         if (innerEntry.getName().endsWith("XML")){
>           //zipInput.read();
>           System.out.println(IOUtils.toString(zipInput));
>         }
>       }
>     }

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