Template:Bug
This template creates a link to the old Bugzilla bugs in default (now imported to JIRA). To find those bugs under their new ID, the link creates a search query. If you directly want to link to JIRA add a second parameter like "jira" or whatever (only checks if there is an second parameter)...
Usage: {{bug|123}} = #123 Link to JIRA: {{bug|6402|jira}} = CORE-6402(add a second parameter, e.g. "jira")