[jira] [Created] (COMPRESS-664) Prevent to throw ZipException from ZipArchiveInputStream.getNextEnry() for empty file

["Radek Kraus (Jira)" <ji...@apache.org>]

Radek Kraus created COMPRESS-664:
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             Summary: Prevent to throw ZipException from ZipArchiveInputStream.getNextEnry() for empty file
                 Key: COMPRESS-664
                 URL: https://issues.apache.org/jira/browse/COMPRESS-664
             Project: Commons Compress
          Issue Type: Bug
          Components: Archivers
    Affects Versions: 1.26.0
            Reporter: Radek Kraus


The version {{1.26.0}} (regression against {{{}1.25.0{}}}) changes behavior of {{ZipArchiveInputStream.getNextEntry()}} for empty file (zero size). Currently {{ZipException("Cannot find zip signature within the file")}} is thrown instead of return null value, when first entry is requested.

This was caused by:
 * [https://github.com/apache/commons-compress/pull/471] (Support preamble garbage in ZipArchiveInputStream)
 * [https://github.com/apache/commons-compress/commit/7d2fde71046c31508483ca80abbdfcdb4d5c78b9]

I guess it is a really regression error, because I don't see a reason why {{ZipException}} should be thrown, even when ??zip can ignore any garbage at the beginning of file up to certain size??.

The _standard_ java {{ZipInputStream}} implementation returns null value too, when {{java.util.zip.ZipInputStream.getNextEntry()}} is invoked.
{code:java}
@Test
public void testGetFirstEntryEmptyZip_Java() throws IOException {
  try (ZipInputStream zin = new ZipInputStream(new ByteArrayInputStream(new byte[0]))) {
    ZipEntry entry = zin.getNextEntry();
    assertNull(entry);
  }
}
{code}
I guess {{commons-compress 1.26.0}} ({{{}ZipArchiveInputStream{}}}) should preserve the same behavior like in version 1.25.0 and like java {{{}ZipInputStream{}}}.

Here is my PR with simple change:
The key is to don't catch {{EOFException}} and transform it into {{{}ZipException{}}}, but simply throw it into {{ZipArchiveInputStream.getNextZipEntry()}} method, when null value is returned (like in case of second and next entries).

Please check/review PR deeply, because I don't understand the complex way how "Garbage" is skipped in {{ZipArchiveInputStream.readFirstLocalFileHeader()}} method.



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