Solve the LaTeX multirow issue with colour panels

This uses the same macro for suppressing column colours which was used
for multi-column. Bottom cells of multi-row must have no colour panels,
else they hide the text which is inserted from the top row.

sphinx/texinputs/sphinxmulticell.sty

@@ -128,7 +128,7 @@
     \xdef\sphinx@multiwidth
            {\the\dimexpr\sphinx@multiwidth+\sphinx@tempb+\tw@\tabcolsep+\arrayrulewidth}%
     % hack the \vline and the colortbl macros
-    \aftergroup\sphinx@hack@vline\aftergroup\sphinx@hack@CT&\relax
+    \sphinx@hack@vline\sphinx@hack@CT&\relax
     % repeat
     \expandafter\sphinx@multispan\expandafter{\the\numexpr#1-\@ne}%
 }%
@@ -210,14 +210,24 @@
 % standard \multirow
 % 1. does not allow verbatim contents,
 % 2. does not allow blank lines in its argument,
-% 3. requires manual intervention if the contents is too long to fit
+% 3. its * specifier means to typeset "horizontally" which is very
+%    bad for paragraph content. 2016 version has = specifier but it
+%    must be used with p type columns only, else results are bad,
+% 4. it requires manual intervention if the contents is too long to fit
 %    in the asked-for number of rows.
+% 5. colour panels (either from \rowcolor or \columncolor) will hide
+%    the bottom part of multirow text, hence manual tuning is needed
+%    to put the multirow insertion at the _bottom_.
+%
 % The Sphinx solution consists in always having contents wrapped
 % in a varwidth environment so that it makes sense to estimate how many
 % lines it will occupy, and then ensure by insertion of suitable struts
 % that the table rows have the needed height. The needed mark-up is done
 % by LaTeX writer, which has its own id for the merged cells.
 %
+% The colour issue is solved by clearing colour panels in all cells,
+% whether or not the multirow is single-column or multi-column.
+%
 % In passing we obtain baseline alignements across rows (only if
 % \arraylinestretch is 1, as LaTeX's does not obey \arraylinestretch in "p"
 % multi-line contents, only first and last line...)
@@ -299,6 +309,8 @@
         \@depth\dimexpr\count@\ht\@arstrutbox+\count@\dp\@arstrutbox-\ht\@arstrutbox\relax
         \@width\z@
   \endgroup
+  % we need this to avoid colour panels hiding bottom parts of multirow text
+  \sphinx@hack@CT
 }%
 \endinput
 %%

sphinx/writers/latex.py

@@ -1480,6 +1480,7 @@ class LaTeXTranslator(nodes.NodeVisitor):
                 self.body.append('&')
                 if nextcell.width == 1:
                     # insert suitable strut for equalizing row heights in multirow
+                    # they also serve to clear colour panels which would hide the text
                     self.body.append('\\sphinxtablestrut{%d}' % nextcell.cell_id)
                 else:
                     # use \multicolumn for wide multirow cell