[horde] Migration Database Horde 5 to Horde 6

[lst_hoe02 at kwsoft.de]

Hello

we are on the way to migrate a old Horde 5 installation to Horde 6 and  
try to use the old database content and do  
"./vendor/bin/horde-db-migrate up" to adjust the schema to Horde 6.  
This somewhat works but Kronolith throws the following error:

Migrating to KronolithUpgradeResourcesToShares (24)
== 24 KronolithUpgradeResourcesToShares: migrating  
============================
-- addColumn('kronolith_sharesng', 'attribute_email', 'text')
    -> 0.0013s
-- addColumn('kronolith_sharesng', 'attribute_members', 'text')
    -> 0.0010s
-- addColumn('kronolith_sharesng', 'attribute_response_type', 'integer')
    -> 0.0009s
-- addColumn('kronolith_sharesng', 'attribute_type', 'integer',  
array('default' => 1))
    -> 0.0204s
-- addColumn('kronolith_sharesng', 'attribute_isgroup', 'integer',  
array('default' => 0))
    -> 0.0181s
-- addColumn('kronolith_shares', 'attribute_email', 'text')
    -> 0.0009s
-- addColumn('kronolith_shares', 'attribute_members', 'text')
    -> 0.0009s
-- addColumn('kronolith_shares', 'attribute_response_type', 'integer')
    -> 0.0009s
-- addColumn('kronolith_shares', 'attribute_type', 'integer',  
array('default' => 1))
    -> 0.0038s
-- addColumn('kronolith_shares', 'attribute_isgroup', 'integer',  
array('default' => 0))
    -> 0.0029s
SQLSTATE[22P02]: Invalid text representation: 7 ERROR:  invalid input  
syntax for type integer: "f"
LINE 1: ... NULL, NULL, 'Besprechungsraum', '', '', 1, 2, 'f', 's:0:...

To my knowledge the entry is some resource defined in Kronolith long  
ago. Truncating "kronolith_resources" before horde-db-migrate fixes  
the problem. Is this expected eg. are resource not able to migrate to  
the new version?

Regards

Andreas