[
https://issues.apache.org/jira/browse/COMPRESS-664?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17820134#comment-17820134
]
Gary D. Gregory commented on COMPRESS-664:
------------------------------------------
[~rkraus]
In git master and snapshot builds.
TY!
> Prevent to throw ZipException from ZipArchiveInputStream.getNextEntry() 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
> Priority: Major
> Fix For: 1.26.1
>
>
> 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:
> https://github.com/apache/commons-compress/pull/486
> The key is to don't catch {{EOFException}} and transform it into
> {{{}ZipException{}}}, but simply throw it into
> {{ZipArchiveInputStream.getNextZipEntry()}} method, where 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.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
