User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0 (Beta/Release) Build ID: 20140506152807 Steps to reproduce: The attribute "displaystyle" of the root <math> element is set explicitly to "true". Actual results: As of version 29.0.1 this attribute is not inherited by <mtable> elements. Presumably it is not inherited by other elements as well but this has not yet been noticed. Expected results: This attribute is expected to be inherited by children. Rolling back to version 28, it is inherited as expected. I am aware that there is a "display" attribute for the root <math> element that can handle inheritance, and if this is the preferred method of setting "displaystyle" then please state that in the comments. Otherwise the inheritance issue needs to be addressed.

The table of attributes in http://www.w3.org/TR/MathML/chapter3.html#presm.mtable says that the default value of the displaystyle attribute on mtable is "false". A paragraph a bit below says "The displaystyle attribute is allowed on the mtable element to set the inherited value of the attribute. If the attribute is not present, the mtable element sets displaystyle to "false" within the table elements." So you need to explicitly use a displaystyle="true" attribute on the mtable element.

In version 28.0, setting either display="block" or displaystyle="true" on the <math> element is inherited by tables, and they appear as they should without an explicit displaystyle="true" on <mtable>. Before I edit numerous files, I would like you to confirm that this inheritance will no longer be supported in current and future versions of Firefox. Thanks much!

(In reply to Frédéric Wang (:fredw) from comment #1) > The table of attributes in > > http://www.w3.org/TR/MathML/chapter3.html#presm.mtable > > says that the default value of the displaystyle attribute on mtable is > "false". A paragraph a bit below says > > "The displaystyle attribute is allowed on the mtable element to set the > inherited value of the attribute. If the attribute is not present, the > mtable element sets displaystyle to "false" within the table elements." I agree with Frédéric's interpretation, even though http://www.w3.org/TR/MathML3/chapter3.html#presm.mstyle may be misleading: "Some attributes, such as displaystyle or scriptlevel (explained below), are inherited from the surrounding context when they are not explicitly set." The description of the behaviour on mtable in more specific and clear that the default behavior is to set displaystyle to "false", like script, mfrac and mroot elements.

(In reply to Paul Masson from comment #2) > In version 28.0, setting either display="block" or displaystyle="true" on > the <math> element is inherited by tables, and they appear as they should > without an explicit displaystyle="true" on <mtable>. Before I edit numerous > files, I would like you to confirm that this inheritance will no longer be > supported in current and future versions of Firefox. Thanks much! That was probably a bug in older versions. In current and future versions, we will certainly continue to follow the MathML standard, which means defaulting displaystyle to false on mtable. Currently, we map displaystyle attribute to a private -moz-math-display CSS property that is not accessible to Web authors. If this property is exposed/standardized, one could just use mtable { -moz-math-display: inherit; } to preserve the old behavior. But at the moment there are no plans for that, so you'll have to add explicit displaystyle attributes everywhere... http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathml.css#305

What about nested tables? Will the attribute displaystyle count as present if it is set on a parent <mtable>, or will it need to be set explicitly on every <mtable>? And if <mtable> is allowed to inherit from a parent <mtable>, why not from any other parent?

Added to the site compat doc, tracker, tweet: https://developer.mozilla.org/en-US/Firefox/Releases/29/Site_Compatibility#MathML https://docs.google.com/spreadsheets/d/1048AVpvbP3O2atsV3i--xLpHCr4PR7TGXyFtgMrvt6Q https://twitter.com/FxSiteCompat/status/467426164571926528

(In reply to Paul Masson from comment #5) > What about nested tables? Will the attribute displaystyle count as present > if it is set on a parent <mtable>, or will it need to be set explicitly on > every <mtable>? And if <mtable> is allowed to inherit from a parent > <mtable>, why not from any other parent? What happens is like if the user-agent stylesheet had a rule mtable { color: red; } you could do <mtable style="color: blue"> but the color will always be reset on descendant mtables. I think it's best to ask the Math WG, as it's probably a problem with the spec. http://lists.w3.org/Archives/Public/www-math/2014Jun/att-0001/displaystyle-mtable.html