LaTeX: add boolean option addstrut to \sphinxbox/\sphinxboxsetup

doc/latex.rst

@@ -1536,9 +1536,18 @@ Here is the complete list of keys:
 - ``border-top-left-radius``, ``border-top-right-radius``,
   ``border-bottom-right-radius``, ``border-bottom-left-radius``,
 - ``box-shadow``,
-- ``border-TeXcolor``, ``background-TeXcolor``, ``box-shadow-TeXcolor``.
+- ``border-TeXcolor``, ``background-TeXcolor``, ``box-shadow-TeXcolor``,
+- and ``addstrut`` which is a boolean key, i.e. to be used as ``addstrut=true``,
+  or ``addstrut`` alone where ``=true`` is omitted, or ``addstrut=false``.
 
-Refer to :ref:`additionalcss` for important syntax information.  The default
+This last key is specific to ``\sphinxbox`` and it means to add a ``\strut``
+so that heights and depths are equalized across various instances,
+independently of text content.  The combination ``addstrut,
+padding-bottom=0pt, padding-top=1pt``  is often satisfactory.  The default is
+``addstrut=false``.e
+
+Refer to :ref:`additionalcss` for important syntax information regarding the
+other keys.  The default
 configuration uses no shadow, a border-width of ``\fboxrule``, a padding of
 ``\fboxsep``, rounded corners (with radius ``\fboxsep``) and background and
 border colors as for the default rendering of code-blocks.  One can modify

sphinx/texinputs/sphinx.sty

@@ -698,6 +698,13 @@ will be set to white}%
     \spx@tempa{div.important_}  {important}
     \spx@tempa{div.tip_}        {tip}
 
+\newif\ifspx@opt@box@addstrut
+\expandafter\def\csname KV@sphinx@box_addstrut\endcsname#1{%
+    \csname spx@opt@box@addstrut#1\endcsname
+}
+\expandafter\def\csname KV@sphinx@box_addstrut@default\endcsname{%
+    \spx@opt@box@addstruttrue
+}
 
 \DeclareDefaultOption{\@unknownoptionerror}
 \ProcessKeyvalOptions*
@@ -818,6 +825,7 @@ will be set to white}%
           {border-bottom-right-radius}{border-bottom-left-radius}%
           {box-shadow}%
           {border-TeXcolor}{background-TeXcolor}{box-shadow-TeXcolor}%
+          {addstrut}{addstrut@default}%
 \do{\expandafter\let\csname KV@sphinxbox@\x\expandafter\endcsname
                     \csname KV@sphinx@box_\x\endcsname}
 \newcommand\sphinxboxsetup{\setkeys{sphinxbox}}

sphinx/texinputs/sphinxpackageboxes.sty

@@ -258,7 +258,8 @@
     \setbox0\hbox\bgroup\aftergroup\spx@boxes@sphinxbox@a
     \let\next=%
 }
-\def\spx@boxes@sphinxbox@a{\spx@boxes@fcolorbox{\box\z@}\endgroup}
+\def\spx@boxes@sphinxbox@a{\spx@boxes@fcolorbox{%
+    \ifspx@opt@box@addstrut\strut\fi\box\z@}\endgroup}
 
 \newcommand\newsphinxbox[2][]{%
    \newcommand#2[1][]{\sphinxbox[#1,##1]}%