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From "Guido Schnepp (JIRA)" <j...@apache.org>
Subject [jira] [Created] (VFS-637) Zip files with legacy encoding and special characters let VFS crash
Date Wed, 21 Jun 2017 14:05:00 GMT
Guido Schnepp created VFS-637:
---------------------------------

             Summary: Zip files with legacy encoding and special characters let VFS crash
                 Key: VFS-637
                 URL: https://issues.apache.org/jira/browse/VFS-637
             Project: Commons VFS
          Issue Type: Bug
         Environment: Windows 10 64 Bit, Java 8
            Reporter: Guido Schnepp


Oracle has reworked the ZipFile object with Java 7. Since then the default constructor used
by commons-vfs2 2.1 is more restrictive than with Java 6. The ZipFile constructor has got
a second parameter (Charset) now for specification of the legacy charset to be used explicitly
if the ZipFile doesn't state its UTF-8 compliance internally. This affects all ZIP files using
a legacy charset for filename encoding but not using UTF-8 is it is common today. This could
be a ZIP file with files containing german umlauts or russian characters in archived file's
filenames, for example.

To support this new parameter with (more or less) default values, the class org.apache.commons.vfs2.provider.zip.ZipFileSystem
has to be extended by a default charset parameter, getter or setter (as you like) to forward
this setting to the java.util.zip.ZipFile constructor.

Quick workaround for me was to create a new OwnZipFileProvider referring to the even new OwnZipFileSystem
(extending ZipFileSystem) with the following modified function. Change has been highlighted:

{{	protected ZipFile createZipFile(final File file) throws FileSystemException {
		try {
			return new ZipFile(file{color:red}*, Charset.forName("IBM437")*{color});
		} catch (final IOException ioe) {
			throw new FileSystemException("vfs.provider.zip/open-zip-file.error", file, ioe);
		}
	}
}}

Presetting to charset 437 as legacy default charset seems to be a a good workaround as stated
in appendix D here: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT :

"D.1 The ZIP format has historically supported only the original IBM PC character encoding
set, commonly referred to as IBM Code Page 437.  This limits storing file name characters
to only those within the original MS-DOS range of values and does not properly support file
names in other character encodings, or  languages. [...]"





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