Index: Bugzilla/Attachment.pm
===================================================================
RCS file: /cvsroot/mozilla/webtools/bugzilla/Bugzilla/Attachment.pm,v
retrieving revision 1.50
diff -u -r1.50 Bugzilla/Attachment.pm
--- Bugzilla/Attachment.pm
+++ Bugzilla/Attachment.pm
@@ -238,6 +238,23 @@
 
 =over
 
+=item C<is_zip>
+
+Returns 1 if the attachment has a content-type that represents a zip archive
+
+=back
+
+=cut
+
+sub is_zip {
+    my $self = shift;
+    my $contenttype = trim($self->contenttype);
+    return $contenttype =~
+      m{^(?:application/(?:x-|)(?:zip|xpinstall|java-archive|jar|winamp-skin)|interface/(?:x-|)winamp-skin)};
+}
+
+=over
+
 =item C<isurl>
 
 whether or not the attachment is a URL
@@ -296,23 +313,32 @@
 
 sub is_viewable {
     my $self = shift;
-    my $contenttype = $self->contenttype;
+    return $self->{is_viewable} if exists $self->{is_viewable};
+    my $contenttype = trim($self->contenttype);
     my $cgi = Bugzilla->cgi;
 
     # We assume we can view all text and image types.
-    return 1 if ($contenttype =~ /^(text|image)\//);
+    if ($contenttype =~ m{^(text|image)/}) {
+        return $self->{is_viewable} = 1;
+    }
 
     # Mozilla can view XUL. Note the trailing slash on the Gecko detection to
     # avoid sending XUL to Safari.
-    return 1 if (($contenttype =~ /^application\/vnd\.mozilla\./)
-                 && ($cgi->user_agent() =~ /Gecko\//));
+    if (($contenttype =~ m{^application/vnd\.mozilla\.}
+         || $self->is_zip)
+        && $cgi->user_agent() =~ m{Gecko/}) {
+        return $self->{is_viewable} = 1;
+    }
 
-    # If it's not one of the above types, we check the Accept: header for any
+    # If it's not one of the above types, we check the Accept: header for any 
     # types mentioned explicitly.
     my $accept = join(",", $cgi->Accept());
-    return 1 if ($accept =~ /^(.*,)?\Q$contenttype\E(,.*)?$/);
 
-    return 0;
+    if ($accept =~ /^(.*,)?\Q$contenttype\E(,.*)?$/) {
+        return $self->{is_viewable} = 1;
+    }
+
+    return $self->{is_viewable} = 0;
 }
 
 =over
Index: template/en/default/attachment/edit.html.tmpl
===================================================================
RCS file: /cvsroot/mozilla/webtools/bugzilla/template/en/default/attachment/edit.html.tmpl,v
retrieving revision 1.47
diff -u -r1.47 template/en/default/attachment/edit.html.tmpl
--- template/en/default/attachment/edit.html.tmpl
+++ template/en/default/attachment/edit.html.tmpl
@@ -105,6 +105,12 @@
       }
     }
 [% END %]
+[% IF attachment.is_zip %]
+  function viewZip()
+    {
+      switchToMode('zip');
+    }
+[% END %]
   function viewRaw()
     {
       switchToMode('raw');
@@ -121,6 +127,10 @@
       if (current_mode == 'edit') {
         hideElementById('editFrame');
         hideElementById('undoEditButton');
+[% IF attachment.is_zip %]
+      } else if (current_mode == 'zip') {
+        hideElementById('zipFrame');
+[% END %]
       } else if (current_mode == 'raw') {
         hideElementById('viewFrame');
 [% IF patchviewerinstalled %]
@@ -141,6 +151,10 @@
       if (mode == 'edit') {
         showElementById('editFrame');
         showElementById('undoEditButton');
+[% IF attachment.is_zip %]
+      } else if (mode == 'zip') {
+        showElementById('zipFrame');
+[% END %]
       } else if (mode == 'raw') {
         showElementById('viewFrame');
 [% IF patchviewerinstalled %]
@@ -307,9 +321,29 @@
             cols    = 80
             wrap    = 'soft'
           %]
-          <iframe id="viewFrame" src="attachment.cgi?id=[% attachment.id %]" style="height: 400px; width: 100%;">
-            <b>You cannot view the attachment while viewing its details because your browser does not support IFRAMEs.
-            <a href="attachment.cgi?id=[% attachment.id %]">View the attachment on a separate page</a>.</b>
+          [% IF attachment.is_zip %]
+            <iframe id="zipFrame"
+                    src="jar:attachment.cgi?id=[% attachment.id %]!/"
+                    type="[% attachment.contenttype FILTER html %]"
+                    style="height: 400px; width: 100%;">
+              <b>You cannot view the contents of this zip file.</b><br>
+              <script type="text/javascript">
+                <!--
+                  document.write('<button type="button" onclick="viewRaw();">View Attachment As Raw</button>');
+                //-->
+              </script>
+            </iframe>
+            [% hide_viewframe = 'display:none;' %]
+          [% ELSE %]
+            [% hide_viewframe = '' %]
+          [% END %]
+          <iframe id="viewFrame"
+                  src="attachment.cgi?id=[% attachment.id %]"
+                  style="height: 400px; width: 100%;[% hide_viewframe %]">
+            <b>You cannot view the attachment while viewing its details
+             because your browser does not support IFRAMEs.
+            <a href="attachment.cgi?id=[% attachment.id %]">View the
+             attachment on a separate page</a>.</b>
           </iframe>
           <script type="text/javascript">
             <!--
@@ -320,6 +354,9 @@
               document.write('<button type="button" id="editButton" onclick="editAsComment();">Edit Attachment As Comment</button>');
               document.write('<button type="button" id="undoEditButton" onclick="undoEditAsComment();" style="display: none;">Undo Edit As Comment</button>');
               document.write('<button type="button" id="redoEditButton" onclick="redoEditAsComment();" style="display: none;">Redo Edit As Comment</button>');
+[% IF attachment.is_zip %]
+              document.write('<button type="button" id="viewZipButton" onclick="viewZip();">View contents of attachment</button>');
+[% END %]
 [% IF patchviewerinstalled %]
               document.write('<button type="button" id="viewDiffButton" onclick="viewDiff();">View Attachment As Diff</button>');
 [% END %]