- provide propagation of errors from mixin guards (in earlier XOTcl versions, these were silently ignored) - don't clobber from guard calls - added new regression tests for mixin and filter guards called via next and trigger errors - fix result code handling for tcl 8.6 - fix tcl stack allocs/deallocs for tcl 8.6 - new debug flag TCL_STACK_ALLOC_TRACE - improve comments - new function CmdIsProc() to handle different behavior of TclIsProc() in 8.6 - passing regression test with tcl 8.6