Created attachment 8700389 [details] hatenablogbug.gif Build identifier: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0 Windows 10 Home. Steps to reproduce: 1.setting clean profile 2.open hatena blog, new entry link(heading navigation),and swtiching "HTML" tab. 3.turn on Google Japanese IME. 4.type to "日本語" Actual results: show wrong conversation candidate. Expected results: show correct conversation candidate. Other browser results: 47.0.2526.106 m (64-bit) is fine. Microsoft Edge 25.10586.0.0(Microsoft EdgeHTML 13.10586) is fine.
Reproduced on Ubuntu14.04 32bit fcitx-mozc and Windows7 MS-IME. Because Hatena insert "\x01\x01" when I type composition text for something ACE editor. (See https://blog.st-hatena.com/js/vendor/ace-builds/src/ace.js?version=76b2f02d7b63d6a752497edddfee6d2e) These control chars are visible on Gecko since Firefox30. see Bug 909344. Unfortunately, Bug 947588 dis not fix this. Pushlog: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=d59e42825c44&tochange=f0d6d67fbc1e
This site is also affected https://ace.c9.io/#nav=about
ISTM this is a site bug: they shouldn't be inserting those control characters into the editable element if they don't want them to appear. According to the CSS WG resolution, all browsers should eventually converge on making them visible, so the "problem" is likely to spread unless the editor code is fixed.
I agree with the diagnosis that this should be fixed in the ACE IME as per comment 5.