Trigger tests for remove $op from hook_comment().

nice work, all tests pass.

+function search_comment_update($a1) {

is it possible to use a better name for $a1?

/**
 * Implementation of hook_comment().
 */
function trigger_comment($a1, $op) {

the doc block needs updating. trigger_comment is now a helper function. might even be worth making it _trigger_comment.

ok, nearly there.

+  search_touch_node(is_array($a1) ? $form_values['nid'] : $form_values->nid);

we know the passed in $form_values is an array, we don't need the is_array checks.

+/**
+ * Helper function for implementations of hook_comment_op().
+ * @param $a1
+ *  Argument, which will be passed to the action.

nitpicking, but we need a blank line in the docblock between "Helper function ..." and the @param part. also, two spaces before "Argument, which will be passed to the action.". more importantly, $a1 can only be one of two things, so best to describe that - form values or comment object.

otherwise, looks good to go.

i get an exception when running search tests:

Trying to get property of non-object    Notice    search.module     690    search_comment_publish()

seems the doco here http://api.drupal.org/api/function/hook_comment/7 is wrong: $op publish passes an array, not the comment object.

otherwise, all looks good.

ok, seems lazy not to fix that. patch attached, all tests pass.

i think this is RTBC.

ouch! we're definitely in need of more tests.

@dereine: are you ok to try to write some tests that fail for the broken code?