Package: zip Version: 3.0-8 Tags: patch Hi,
as the unzip package is not able to unpack split (i.e. foo.zip, foo.z01, foo.z02 etc.) zip archives, they need to be restored to a single .zip file via "zip -F <split.zip> --out <combined.zip>" first, after which <combined.zip> can be extracted via unzip. However, if the split has been done on a multiple of 16kB and is split between more than two zipfiles, the restoration fails: $ dd if=/dev/urandom of=blob bs=1M count=10 10+0 records in 10+0 records out 10485760 bytes (10 MB) copied, 1.00457 s, 10.4 MB/s $ zip -r -s2m foo.zip blob adding: blob (deflated 0%) $ mv blob blob.orig $ zip -F foo.zip --out tmp.zip Fix archive (-F) - assume mostly intact archive copying: blob $ unzip tmp.zip Archive: tmp.zip inflating: blob error: invalid compressed data to inflate $ md5sum blob.orig blob cfbe654be5da3e5ad6104ae47fb62563 blob.orig dc83002390d9da9936cb21df471db507 blob The attached test script can be used to easily check different splitsizes (in kB, note that 64k is the smallest allowed splitsize, the script does not check the input): $ splitzip-check.sh 64 Checking with splitsize of 64 kB... Failed! MD5 of orig: dbc72bd1b1123f90809371644f8c504b MD5 of test: 80ed7c7d363e2b0e46167e225ef36a37 $ splitzip-check.sh 65 Checking with splitsize of 65 kB... OK! MD5 of orig: 050ead6ad874654db1b9fccde3511b63 MD5 of test: 050ead6ad874654db1b9fccde3511b63 $ rm -rf zipsplit-check/ We have diagnosed the problem and it is due to a missing check on eof during a while-loop in bfcopy(). This loop copies the split zips in chunks of the blocksize, which is 16kB. If the split zip file ends at exactly that, the next read() returns 0 bytes and as eof is not checked for, the while loop aborts and subsequently also the copy operation and finally the check for more .z0* files to copy. This means that only the first two of potentially many more zipfiles are getting copied, resulting in a broken combined zipfile. The attached patch fixes this (also for the "zip -FF" case). This bug report and the corresponding fix have been commissioned by the City of Munich's LiMux project. Michael -- Michael Banck Projektleiter / Berater Tel.: +49 (2161) 4643-171 Fax: +49 (2161) 4643-100 Email: michael.ba...@credativ.de credativ GmbH, HRB Mönchengladbach 12080 USt-ID-Nummer: DE204566209 Hohenzollernstr. 133, 41061 Mönchengladbach Geschäftsführung: Dr. Michael Meskes, Jörg Folz, Sascha Heuer
splitzip-check.sh
Description: application/shellscript
--- Begin Message ---Index: zip-3.0/fileio.c =================================================================== --- zip-3.0.orig/fileio.c 2014-06-30 13:08:39.114364770 +0200 +++ zip-3.0/fileio.c 2014-06-30 13:20:22.306008671 +0200 @@ -1619,7 +1619,10 @@ if ((k = fread(b, 1, brd, in_file)) == 0) { - if (fix == 2 && k < brd) { + if (feof(in_file) && !ferror(in_file)) { + /* do nothing */ + } + else if (fix == 2 && k < brd) { free((zvoid *)b); return ZE_READ; }
--- End Message ---
