Sweet! I'm glad you found and fixed the second issue.

Changes have been made in Git (master):

commit 984ec55759dd59390686122d37722dfb4b9f4884
Author: Jan Schneider <jan@horde.org>
Date:   Tue Mar 24 12:18:53 2015 +0100

     Deal with both formats of the _attachments hash (Bug #13268).

     In the end I was able to reproducable that edge case.
     There is no use in trying to clean this mess up, because it would 
break the
     _attachments API that is used outside of Kolab_Storage. This 
needs refactoring
     for H6.

  .../lib/Horde/Kolab/Storage/Cache/Data.php         |    8 +++++++-
  1 files changed, 7 insertions(+), 1 deletions(-)

http://github.com/horde/horde/commit/984ec55759dd59390686122d37722dfb4b9f4884

good! I'll try to break it again with your latest changes + a clean cache.
(will take some time though until I get to it)

I haven't been able to reproduce the edge cases anymore that we talked 
about. Probably just some stale and broken cache entries from 
development.

Changes have been made in Git (master):

commit 6aec869cebdc7e7315f4dfd3624901363449bb60
Author: Jan Schneider <jan@horde.org>
Date:   Fri Mar 20 19:47:38 2015 +0100

     [jan] Fix deleting object attachments from cache (Bug #13268).

  .../lib/Horde/Kolab/Storage/Cache/Data.php         |    2 +-
  framework/Kolab_Storage/package.xml                |    4 ++--
  2 files changed, 3 insertions(+), 3 deletions(-)

http://github.com/horde/horde/commit/6aec869cebdc7e7315f4dfd3624901363449bb60

ping

Ok, I've added the usual lot of debug statements
and found out what's going on:

The $delete() array contains a list of "IMAP uids" (=backend IDs)
that got deleted - including the corresponding object uid.

When you update a contact in turba, $_data[self::OBJECTS][$object_id]
will contain the *current* datastructure as passed on by the turba 
Kolab driver.

There is no 'id' column in '_attachments' as
the '_attachments' datastructure looks like this:
-------------------------
Array
(
     [photo.jpg] => Array
         (
             [type] => image/jpeg
             [content] => Resource id #331
         )
)
-------------------------


The transformation of that data structure for the on-disc format
of the cache happens a few lines below.

Things are different when you delete a contact,
'_attachments' then looks like this as it's not
updated by the turba Kolab driver itself:
-------------------------------------------------------
[_attachments] => Array
(
     [id] => Array
         (
             [0] => photo.jpg
         )

     [type] => Array
         (
             [image/jpeg] => Array
                 (
                     [0] => photo.jpg
                 )

         )

)
-------------------------------------------------------

Please apply the attached patch to handle both cases.

I've tested the patch with debug statements in place
to verify it does delete the correct attachment
in both the modify and delete case of a contact object.

There is a difference between how the attachments are passed to 
store() ($objects array with '_attachments' being an ID->attachment 
hash) and how they are stored in the Data object ($this->_data with 
'_attachments' being a list of attachment hashes).

while editing works fine and there's only one attachment in the 
produced email,
it triggers the given warning for me every time on modification (using 
git "master").

The foreach() calls I provided are in the same function "store()", so 
it's the same datastructure.
To me it looks like $object[_attachments[]['id']] is used before it's 
actually built.

If you look at the code, the second iteration is filling in the 'id' field.
--------------------------------------------------------
foreach ($object['_attachments'] as $id => $attachment) {
     $attachments['id'][] = $id;
--------------------------------------------------------

IIRC those are different data structures in different situations. How 
did you actually trigger an error with the current code? Editing a 
contact picture with the Horde_Form image editing buttons worked 
without problems.

should there be an 'id' field in the datastructure? I thought the key 
of the '_attachments' array is already the id?

The code in question iterates of the attachments like this:
------------------------------------------
foreach ($object['_attachments']['id'] as $id) {
------------------------------------------

Other pieces of code iterate like this:
------------------------------------------
foreach ($object['_attachments'] as $id => $attachment) {
------------------------------------------

Cannot reproduce. Works perfectly fine here and without any errors or notices.

Hi,

when you modify a contact picture in turba (say: rotate it), the 
following error is logged:

2014-06-19T15:52:34+02:00 WARN: HORDE [turba] PHP ERROR: Invalid 
argument supplied for foreach() [pid 2863 on line 461 of 
"/datastore/DEVEL/framework/Kolab_Storage/lib/Horde/Kolab/Storage/Cache/Data.php"]

The structure of $object['_attachments'] looks like this:
---------------------------------
Array
(
     [photo.jpg] => Array
         (
             [type] => image/jpeg
             [content] => Resource id #331
         )

)
---------------------------------

-> no "id" value in there.

Cheers,
Thomas