Tickets :: Comment on [#4670] unable to open zip files on Mac OS X

* Your Email Address
* Spam protection	Enter the letters below: \ /. .___.\ / __ >< \| \| >< / ` / \\|___ \| / \\__.
Comment	> The "Download all attachments in zip file" option sometimes results > in a file that cannot be opened by the default zip handler > (BOMArchiveHelper) on Mac OS X. Zipinfo reports the contents of the > file properly. The file can be "repaired" using the following steps: > > zipnote file.zip >tmp > > zipnote -w file.zip <tmp > > In doing this we noted that 12 bytes per file get dropped from the archive. > > The mailing list reports two other zip handlers having problems with > IMP generated zip files: 7-Zip and Stuffit 11. > > In Horde/Compress/zip.php I found at line 346: > > /* "Data descriptor" segment (optional but necessary if archive is > > not served as file). */ > > $fr .= pack('V', $crc); > > $fr .= pack('V', $c_len); > > $fr .= pack('V', $unc_len); > > This amounts to 12 bytes that gets added for each file in the > archive. These are the 12 bytes that zipnote is stripping out for > each file. PKWare's appnote.txt indicates there is confusion in the > use of the data descriptor segment (should it have a signature, > should it only be used in stream processing, which bit to set if it > will be used) and promises a future appnote to resolve the confusion. > > > > Since we did not want to touch every Macintosh on campus to set it to > use a different default zip handler we went ahead and commented out > the data descriptor segment. > >
Attachment
Watch this ticket

Saved Queries