LaTeX writer: Fix tables

- [x] Fix a bug introduced in 66378062b622b0815a1a2ddce5d557e3ad13330c, which
  causes the table caption to repeat across all pages
- [x] Address the issues discussed
  [here](https://groups.google.com/forum/#!msg/pandoc-discuss/qMu6_5lYy0o/ZAU7lzAIKw0J)
  regarding the extra vertical space.
  - [ ] NOTE: This will cause multiline table cells to appear unpadded. See
    http://tex.stackexchange.com/questions/34971
  - [x] Use [`\tabularnewline`](http://tex.stackexchange.com/questions/78796)
    instead of `\\`.

2 files changed, 74 insertions, 65 deletions

diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index d200ecee1..6c17401d0 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -471,12 +471,18 @@ blockToLaTeX (Header level (id',classes,_) lst) =
 blockToLaTeX (Table caption aligns widths heads rows) = do
   headers <- if all null heads
                 then return empty
-                else ($$ "\\midrule\\endhead") `fmap`
+                else ($$ "\\midrule\n") `fmap`
                       (tableRowToLaTeX True aligns widths) heads
+  let endhead = if all null heads
+                   then empty
+                   else text "\\endhead"
   captionText <- inlineListToLaTeX caption
   let capt = if isEmpty captionText
                 then empty
-                else text "\\caption" <> braces captionText <> "\\\\"
+                else text "\\caption" <> braces captionText
+                         <> "\\tabularnewline\n\\toprule\n"
+                         <> headers
+                         <> "\\endfirsthead"
   rows' <- mapM (tableRowToLaTeX False aligns widths) rows
   let colDescriptors = text $ concat $ map toColDescriptor aligns
   modify $ \s -> s{ stTable = True }
@@ -484,8 +490,9 @@ blockToLaTeX (Table caption aligns widths heads rows) = do
               braces ("@{}" <> colDescriptors <> "@{}")
               -- the @{} removes extra space at beginning and end
          $$ capt
-         $$ "\\toprule\\addlinespace"
+         $$ "\\toprule"
          $$ headers
+         $$ endhead
          $$ vcat rows'
          $$ "\\bottomrule"
          $$ "\\end{longtable}"
@@ -512,7 +519,7 @@ tableRowToLaTeX header aligns widths cols = do
   let scaleFactor = 0.97 ** fromIntegral (length aligns)
   let widths' = map (scaleFactor *) widths
   cells <- mapM (tableCellToLaTeX header) $ zip3 widths' aligns cols
-  return $ hsep (intersperse "&" cells) $$ "\\\\\\addlinespace"
+  return $ hsep (intersperse "&" cells) <> "\\tabularnewline"
 
 -- For simple latex tables (without minipages or parboxes),
 -- we need to go to some lengths to get line breaks working:
diff --git a/tests/tables.latex b/tests/tables.latex
index eb665204d..1349960a3 100644
--- a/tests/tables.latex
+++ b/tests/tables.latex
@@ -1,58 +1,57 @@
 Simple table with caption:
 
 \begin{longtable}[c]{@{}rlcl@{}}
-\caption{Demonstration of simple table syntax.}\\
-\toprule\addlinespace
-Right & Left & Center & Default
-\\\addlinespace
-\midrule\endhead
-12 & 12 & 12 & 12
-\\\addlinespace
-123 & 123 & 123 & 123
-\\\addlinespace
-1 & 1 & 1 & 1
-\\\addlinespace
+\caption{Demonstration of simple table syntax.}\tabularnewline
+\toprule
+Right & Left & Center & Default\tabularnewline
+\midrule
+\endfirsthead
+\toprule
+Right & Left & Center & Default\tabularnewline
+\midrule
+\endhead
+12 & 12 & 12 & 12\tabularnewline
+123 & 123 & 123 & 123\tabularnewline
+1 & 1 & 1 & 1\tabularnewline
 \bottomrule
 \end{longtable}
 
 Simple table without caption:
 
 \begin{longtable}[c]{@{}rlcl@{}}
-\toprule\addlinespace
-Right & Left & Center & Default
-\\\addlinespace
-\midrule\endhead
-12 & 12 & 12 & 12
-\\\addlinespace
-123 & 123 & 123 & 123
-\\\addlinespace
-1 & 1 & 1 & 1
-\\\addlinespace
+\toprule
+Right & Left & Center & Default\tabularnewline
+\midrule
+\endhead
+12 & 12 & 12 & 12\tabularnewline
+123 & 123 & 123 & 123\tabularnewline
+1 & 1 & 1 & 1\tabularnewline
 \bottomrule
 \end{longtable}
 
 Simple table indented two spaces:
 
 \begin{longtable}[c]{@{}rlcl@{}}
-\caption{Demonstration of simple table syntax.}\\
-\toprule\addlinespace
-Right & Left & Center & Default
-\\\addlinespace
-\midrule\endhead
-12 & 12 & 12 & 12
-\\\addlinespace
-123 & 123 & 123 & 123
-\\\addlinespace
-1 & 1 & 1 & 1
-\\\addlinespace
+\caption{Demonstration of simple table syntax.}\tabularnewline
+\toprule
+Right & Left & Center & Default\tabularnewline
+\midrule
+\endfirsthead
+\toprule
+Right & Left & Center & Default\tabularnewline
+\midrule
+\endhead
+12 & 12 & 12 & 12\tabularnewline
+123 & 123 & 123 & 123\tabularnewline
+1 & 1 & 1 & 1\tabularnewline
 \bottomrule
 \end{longtable}
 
 Multiline table with caption:
 
 \begin{longtable}[c]{@{}clrl@{}}
-\caption{Here's the caption. It may span multiple lines.}\\
-\toprule\addlinespace
+\caption{Here's the caption. It may span multiple lines.}\tabularnewline
+\toprule
 \begin{minipage}[b]{0.13\columnwidth}\centering
 Centered Header
 \end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
@@ -61,9 +60,21 @@ Left Aligned
 Right Aligned
 \end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
 Default aligned
-\end{minipage}
-\\\addlinespace
-\midrule\endhead
+\end{minipage}\tabularnewline
+\midrule
+\endfirsthead
+\toprule
+\begin{minipage}[b]{0.13\columnwidth}\centering
+Centered Header
+\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
+Left Aligned
+\end{minipage} & \begin{minipage}[b]{0.14\columnwidth}\raggedleft
+Right Aligned
+\end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
+Default aligned
+\end{minipage}\tabularnewline
+\midrule
+\endhead
 \begin{minipage}[t]{0.13\columnwidth}\centering
 First
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -72,8 +83,7 @@ row
 12.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Example of a row that spans multiple lines.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \begin{minipage}[t]{0.13\columnwidth}\centering
 Second
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -82,15 +92,14 @@ row
 5.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Here's another one. Note the blank line between rows.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \bottomrule
 \end{longtable}
 
 Multiline table without caption:
 
 \begin{longtable}[c]{@{}clrl@{}}
-\toprule\addlinespace
+\toprule
 \begin{minipage}[b]{0.13\columnwidth}\centering
 Centered Header
 \end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
@@ -99,9 +108,9 @@ Left Aligned
 Right Aligned
 \end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
 Default aligned
-\end{minipage}
-\\\addlinespace
-\midrule\endhead
+\end{minipage}\tabularnewline
+\midrule
+\endhead
 \begin{minipage}[t]{0.13\columnwidth}\centering
 First
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -110,8 +119,7 @@ row
 12.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Example of a row that spans multiple lines.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \begin{minipage}[t]{0.13\columnwidth}\centering
 Second
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -120,28 +128,24 @@ row
 5.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Here's another one. Note the blank line between rows.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \bottomrule
 \end{longtable}
 
 Table without column headers:
 
 \begin{longtable}[c]{@{}rlcr@{}}
-\toprule\addlinespace
-12 & 12 & 12 & 12
-\\\addlinespace
-123 & 123 & 123 & 123
-\\\addlinespace
-1 & 1 & 1 & 1
-\\\addlinespace
+\toprule
+12 & 12 & 12 & 12\tabularnewline
+123 & 123 & 123 & 123\tabularnewline
+1 & 1 & 1 & 1\tabularnewline
 \bottomrule
 \end{longtable}
 
 Multiline table without column headers:
 
 \begin{longtable}[c]{@{}clrl@{}}
-\toprule\addlinespace
+\toprule
 \begin{minipage}[t]{0.13\columnwidth}\centering
 First
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -150,8 +154,7 @@ row
 12.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Example of a row that spans multiple lines.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \begin{minipage}[t]{0.13\columnwidth}\centering
 Second
 \end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
@@ -160,7 +163,6 @@ row
 5.0
 \end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
 Here's another one. Note the blank line between rows.
-\end{minipage}
-\\\addlinespace
+\end{minipage}\tabularnewline
 \bottomrule
 \end{longtable}