Zip files downloaded from Fossil can not be opened with the 7-Zip program. After some poking in the Zip File Format Specification, I found that the "disk number start" field in the File Header of the Central directory structure was set to 1 instead off 0.

The following patch solves this problem:

<pre>
--- Fossil-266b6127f6/src/zip.c 2009-06-20 11:06:00 +0000
+++ Fossil-266b6127f6-new/src/zip.c     2009-06-20 21:35:42 +0000
@@ -194,7 +194,7 @@
   put16(&zBuf[28], nameLen);
   put16(&zBuf[30], 0);
   put16(&zBuf[32], 0);
-  put16(&zBuf[34], 1);
+  put16(&zBuf[34], 0);
   put16(&zBuf[36], 0);
   put32(&zBuf[38], ((unsigned)(0100000 | 0644))<<16);
   put32(&zBuf[42], iStart);
</pre>

<pre>
--
Thomas Schnurrenberger
</pre>

7-Zip is unable to open Zip files generated by Fossil