LaTeX writer: Fix regression in table header position.

In recent versions the table headers were no longer bottom-aligned
(if more than one line).  This patch fixes that by using minipages
for table headers in non-simple tables.

Closes #7347.

6 files changed, 79 insertions, 18 deletions

diff --git a/src/Text/Pandoc/Writers/LaTeX/Table.hs b/src/Text/Pandoc/Writers/LaTeX/Table.hs
index 16f63314b..8dc7d1162 100644
--- a/src/Text/Pandoc/Writers/LaTeX/Table.hs
+++ b/src/Text/Pandoc/Writers/LaTeX/Table.hs
@@ -16,6 +16,7 @@ module Text.Pandoc.Writers.LaTeX.Table
   ) where
 import Control.Monad.State.Strict
 import Data.List (intersperse)
+import qualified Data.List.NonEmpty as NonEmpty
 import Data.List.NonEmpty (NonEmpty ((:|)))
 import Data.Text (Text)
 import qualified Data.Text as T
@@ -243,8 +244,13 @@ cellToLaTeX :: PandocMonad m
             -> Ann.Cell
             -> LW m (Doc Text)
 cellToLaTeX blockListToLaTeX celltype annotatedCell = do
-  let (Ann.Cell _specs _colnum cell) = annotatedCell
-  let (Cell _attr align rowspan colspan blocks) = cell
+  let (Ann.Cell specs _colnum cell) = annotatedCell
+  let hasWidths = snd (NonEmpty.head specs) /= ColWidthDefault
+  let specAlign = fst (NonEmpty.head specs)
+  let (Cell _attr align' rowspan colspan blocks) = cell
+  let align = case align' of
+                AlignDefault -> specAlign
+                _            -> align'
   beamer <- gets stBeamer
   externalNotes <- gets stExternalNotes
   inMinipage <- gets stInMinipage
@@ -256,7 +262,7 @@ cellToLaTeX blockListToLaTeX celltype annotatedCell = do
         Plain{} -> True
         _       -> False
   result <-
-    if all isPlainOrPara blocks
+    if not hasWidths || (celltype /= HeaderCell && all isPlainOrPara blocks)
        then
          blockListToLaTeX $ walk fixLineBreaks $ walk displayMathToInline blocks
        else do
@@ -290,3 +296,4 @@ cellToLaTeX blockListToLaTeX celltype annotatedCell = do
 data CellType
   = HeaderCell
   | BodyCell
+  deriving Eq
diff --git a/test/command/5367.md b/test/command/5367.md
index 2d3a5e52e..a67011c2f 100644
--- a/test/command/5367.md
+++ b/test/command/5367.md
@@ -24,11 +24,15 @@ hello\footnote{doc footnote}
   >{\centering\arraybackslash}p{(\columnwidth - 0\tabcolsep) * \real{0.17}}@{}}
 \caption[Sample table.]{Sample table.\footnote{caption footnote}}\tabularnewline
 \toprule
-Fruit\footnote{header footnote} \\
+\begin{minipage}[b]{\linewidth}\centering
+Fruit\footnote{header footnote}
+\end{minipage} \\
 \midrule
 \endfirsthead
 \toprule
-Fruit{} \\
+\begin{minipage}[b]{\linewidth}\centering
+Fruit{}
+\end{minipage} \\
 \midrule
 \endhead
 Bans\footnote{table cell footnote} \\
diff --git a/test/tables.latex b/test/tables.latex
index afa14d845..9d111fa7a 100644
--- a/test/tables.latex
+++ b/test/tables.latex
@@ -56,11 +56,27 @@ Multiline table with caption:
   >{\raggedright\arraybackslash}p{(\columnwidth - 6\tabcolsep) * \real{0.35}}@{}}
 \caption{Here's the caption. It may span multiple lines.}\tabularnewline
 \toprule
-Centered Header & Left Aligned & Right Aligned & Default aligned \\
+\begin{minipage}[b]{\linewidth}\centering
+Centered Header
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Left Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedleft
+Right Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Default aligned
+\end{minipage} \\
 \midrule
 \endfirsthead
 \toprule
-Centered Header & Left Aligned & Right Aligned & Default aligned \\
+\begin{minipage}[b]{\linewidth}\centering
+Centered Header
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Left Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedleft
+Right Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Default aligned
+\end{minipage} \\
 \midrule
 \endhead
 First & row & 12.0 & Example of a row that spans multiple lines. \\
@@ -76,7 +92,15 @@ Multiline table without caption:
   >{\raggedleft\arraybackslash}p{(\columnwidth - 6\tabcolsep) * \real{0.16}}
   >{\raggedright\arraybackslash}p{(\columnwidth - 6\tabcolsep) * \real{0.35}}@{}}
 \toprule
-Centered Header & Left Aligned & Right Aligned & Default aligned \\
+\begin{minipage}[b]{\linewidth}\centering
+Centered Header
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Left Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedleft
+Right Aligned
+\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
+Default aligned
+\end{minipage} \\
 \midrule
 \endhead
 First & row & 12.0 & Example of a row that spans multiple lines. \\
diff --git a/test/tables/nordics.latex b/test/tables/nordics.latex
index 1b5929bad..1dcac7319 100644
--- a/test/tables/nordics.latex
+++ b/test/tables/nordics.latex
@@ -5,13 +5,31 @@
   >{\raggedright\arraybackslash}p{(\columnwidth - 6\tabcolsep) * \real{0.20}}@{}}
 \caption{States belonging to the \emph{Nordics.}}\tabularnewline
 \toprule
-Name & Capital & \vtop{\hbox{\strut Population}\hbox{\strut (in 2018)}} &
-\vtop{\hbox{\strut Area}\hbox{\strut (in km\textsuperscript{2})}} \\
+\begin{minipage}[b]{\linewidth}\centering
+Name
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Capital
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Population\\
+(in 2018)
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Area\\
+(in km\textsuperscript{2})
+\end{minipage} \\
 \midrule
 \endfirsthead
 \toprule
-Name & Capital & \vtop{\hbox{\strut Population}\hbox{\strut (in 2018)}} &
-\vtop{\hbox{\strut Area}\hbox{\strut (in km\textsuperscript{2})}} \\
+\begin{minipage}[b]{\linewidth}\centering
+Name
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Capital
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Population\\
+(in 2018)
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Area\\
+(in km\textsuperscript{2})
+\end{minipage} \\
 \midrule
 \endhead
 Denmark & Copenhagen & 5,809,502 & 43,094 \\
diff --git a/test/tables/planets.latex b/test/tables/planets.latex
index 8238c43f3..b22c3adeb 100644
--- a/test/tables/planets.latex
+++ b/test/tables/planets.latex
@@ -1,18 +1,18 @@
 \begin{longtable}[]{@{}cclrrrrrrrrl@{}}
 \caption{Data about the planets of our solar system.}\tabularnewline
 \toprule
-\multicolumn{2}{l}{} & Name & Mass (10\^{}24kg) & Diameter (km) & Density
+\multicolumn{2}{c}{} & Name & Mass (10\^{}24kg) & Diameter (km) & Density
 (kg/m\^{}3) & Gravity (m/s\^{}2) & Length of day (hours) & Distance from Sun
 (10\^{}6km) & Mean temperature (C) & Number of moons & Notes \\
 \midrule
 \endfirsthead
 \toprule
-\multicolumn{2}{l}{} & Name & Mass (10\^{}24kg) & Diameter (km) & Density
+\multicolumn{2}{c}{} & Name & Mass (10\^{}24kg) & Diameter (km) & Density
 (kg/m\^{}3) & Gravity (m/s\^{}2) & Length of day (hours) & Distance from Sun
 (10\^{}6km) & Mean temperature (C) & Number of moons & Notes \\
 \midrule
 \endhead
-\multicolumn{2}{l}{\multirow{4}{*}{Terrestrial planets}} & Mercury & 0.330 &
+\multicolumn{2}{c}{\multirow{4}{*}{Terrestrial planets}} & Mercury & 0.330 &
 4,879 & 5427 & 3.7 & 4222.6 & 57.9 & 167 & 0 & Closest to the Sun \\
 & & Venus & 4.87 & 12,104 & 5243 & 8.9 & 2802.0 & 108.2 & 464 & 0 & \\
 & & Earth & 5.97 & 12,756 & 5514 & 9.8 & 24.0 & 149.6 & 15 & 1 & Our world \\
@@ -24,7 +24,7 @@ planet \\
 & \multirow{2}{*}{Ice giants} & Uranus & 86.8 & 51,118 & 1271 & 8.7 & 17.2 &
 2872.5 & -195 & 27 & \\
 & & Neptune & 102 & 49,528 & 1638 & 11.0 & 16.1 & 4495.1 & -200 & 14 & \\
-\multicolumn{2}{l}{Dwarf planets} & Pluto & 0.0146 & 2,370 & 2095 & 0.7 &
+\multicolumn{2}{c}{Dwarf planets} & Pluto & 0.0146 & 2,370 & 2095 & 0.7 &
 153.3 & 5906.4 & -225 & 5 & Declassified as a planet in 2006. \\
 \bottomrule
 \end{longtable}
diff --git a/test/tables/students.latex b/test/tables/students.latex
index 87efb0851..3d4d287d9 100644
--- a/test/tables/students.latex
+++ b/test/tables/students.latex
@@ -3,11 +3,19 @@
   >{\raggedright\arraybackslash}p{(\columnwidth - 2\tabcolsep) * \real{0.50}}@{}}
 \caption{List of Students}\tabularnewline
 \toprule
-Student ID & Name \\
+\begin{minipage}[b]{\linewidth}\centering
+Student ID
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Name
+\end{minipage} \\
 \midrule
 \endfirsthead
 \toprule
-Student ID & Name \\
+\begin{minipage}[b]{\linewidth}\centering
+Student ID
+\end{minipage} & \begin{minipage}[b]{\linewidth}\centering
+Name
+\end{minipage} \\
 \midrule
 \endhead
 \multicolumn{2}{l}{Computer Science} \\