Created attachment 266084 [details] testcase The following entities are defined as a sequence space + combining char in the XML Entity spec: DownBreve U+0020 U+0311 tdot, TripleDot: U+0020 U+20DB DotDot: U+0020 U+20DC From the spec: "For reasons explained further in [Charmod-norm], it is not advisable to to start the replacement text of an entity with a combining character, as then potentially different results may be produced depending on the order in which entity expansion and Unicode normalisation are performed. As far as possible this specification uses non-combining characters, however, in the cases tdot, TripleDot and DotDot Unicode only has combining forms of the accents, and so the entity replacement text starts with a space, to avoid the possibility that the expansion of the entity combines with preceding text." I attach a testcase and here another one: http://tests.mathml-association.org/mathml/relations/html5-tree/entities.html Here is the corresponding bug on Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=1223829
Created attachment 266085 [details] untested patch
Created attachment 266089 [details] Patch
INVALID per https://github.com/whatwg/html-build/issues/42