User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 Build ID: 20150409144858 Steps to reproduce: See: http://jsfiddle.net/1cja691a/ Since the default css of textarea "word-wrap: break-word" is somehow conflict with "white-space: pre" (according to http://stackoverflow.com/questions/4413015/browser-compatible-word-wrap-and-whitespace-pre ), the result is very different on various browsers. However, only the Firefox's behavior is different from others (IE, Chrome).
See the long discussion and various testcases in bug 82711. The white-space handling we have matches Safari and basic sanity, and indcidentally the spec, exactly. The only difference is the handling of the interaction of "word-wrap: break-word" and "white-space: pre". As far as that interaction goes, http://dev.w3.org/csswg/css-text-3/#white-space-property is very clear that "white-space: pre" means that only forced linebreaks are taken, and http://dev.w3.org/csswg/css-text-3/#line-breaking is clear about wrapping introducing soft breaks, not forced breaks. Furthermore, http://dev.w3.org/csswg/css-text-3/#overflow-wrap-property is very clear about it only having an effect when the white-space value allows wrapping. So as far as I can tell, we're just doing exactly what the specs say to do here. What exact behavior change are you proposing we make?