If I type something into a field, then try to navigate to a different page without processing the data, JIRA helpfully pops up a Confirm Navigation dialog that makes sure that I really did mean to trash that info.

JIRA also does that for text entered into the search field, and that is wrong. Search text is disposable, and for various reasons related to UI norms, it is almost impossible that someone would inadvertently lose text they typed into a search box by inadvertently clicking on a link or browser navigation button.