- fix CVE-2026-61915: double-free in the CalDAV VPATCH BYPARAM selector, reachable by an authenticated calendar user patching a resource with two or more properties of the matched kind - do not free VPATCH parameters already removed by reference: the parameter stays owned by libical after icalproperty_remove_parameter_by_ref(), so the following icalparameter_free() double-freed it and aborted the CalDAV worker on any VPATCH carrying a PATCH-ACTION parameter - use strcmpsafe/strncmpsafe for PATCHACTION string matching: icalparameter_get_xvalue() and icalproperty_get_value_as_string() may return NULL on the same VPATCH path - disable the cassandane test runner by default: on i686 its noarch perl dependencies are absent from the i686 mirror of centos8.4-Devel, and on x86_64 the prebuilt imaptest helper dies on SIGBUS (769 run, 0 failures, 64 errors, all the same crash); the cunit suite continues to run on both architectures