Index: openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl,v
diff -u -r1.133.2.50 -r1.133.2.51
--- openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	10 Sep 2014 18:17:20 -0000	1.133.2.50
+++ openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	28 Sep 2014 15:55:41 -0000	1.133.2.51
@@ -10,6 +10,43 @@
 
 namespace eval util {}
 
+ad_proc util::zip_file {
+    -source:required
+    -destination:required
+} {
+    Create a zip file.
+    If source is a directory, archive will contain all files into directory without the trailing directory itself.
+} {
+    set cmd [list exec]
+    switch $::tcl_platform(platform) {
+      windows {
+	lappend cmd cmd.exe /c
+      }
+      default {
+	lappend cmd bash -c
+      }
+    }
+    if {[file isfile $source]} {
+      set filename [file tail $source]
+      set in_path  [file dirname $source]
+    } else {
+      set filename "."
+      set in_path  $source
+    }
+    # To avoid having the full path of the file included in the archive,
+    # we must first cd to the source directory. zip doesn't have an option
+    # to do this without building a little script...
+    set zip_cmd [list]
+    lappend zip_cmd "cd $in_path"
+    lappend zip_cmd "zip -r \"${destination}\" \"${filename}\""
+    set zip_cmd [join $zip_cmd " && "]
+    
+    lappend cmd $zip_cmd
+    
+    # create the archive
+    {*}$cmd
+}
+
 # Let's define the nsv arrays out here, so we can call nsv_exists
 # on their keys without checking to see if it already exists.
 # we create the array by setting a bogus key.
Index: openacs-4/packages/file-storage/www/download-zip.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/download-zip.tcl,v
diff -u -r1.6.6.3 -r1.6.6.4
--- openacs-4/packages/file-storage/www/download-zip.tcl	5 Aug 2014 17:46:33 -0000	1.6.6.3
+++ openacs-4/packages/file-storage/www/download-zip.tcl	28 Sep 2014 15:55:41 -0000	1.6.6.4
@@ -40,12 +40,9 @@
 
 set out_file [file join ${out_path} ${download_name}]
 
-# get the archive command
-set cmd "zip -r \"$out_file\" ."
-
 # create the archive
 with_catch errmsg {
-    exec bash -c "cd $in_path; $cmd; cd -"
+    util::zip_file -source $in_path -destination $out_file
 } {
     # some day we'll do something useful here
     file delete -force $in_path