I have an html page with
and searching for "-c" + "Whole words" option does not find anything, but it somehow works searching for "-crc32"!
Strange. There seems to be a problem with finding the minus sign in the first position of the text node, with Whole Words selected. You might need to file a bug report:
See also: https://bugzilla.mozilla.org/page.cgi?id=bug-writing.html