LaTeX reader: resolve `\ref` to table numbers.

Closes #6137.

3 files changed, 74 insertions, 25 deletions

diff --git a/src/Text/Pandoc/Readers/LaTeX.hs b/src/Text/Pandoc/Readers/LaTeX.hs
index 0bafa0d19..cae7a23b7 100644
--- a/src/Text/Pandoc/Readers/LaTeX.hs
+++ b/src/Text/Pandoc/Readers/LaTeX.hs
@@ -2078,33 +2078,40 @@ addImageCaption = walkM go
           case attr' of
                ("", _, _)    -> return ()
                (ident, _, _) -> do
-                  st <- getState
-                  let chapnum =
-                        case (sHasChapters st, sLastHeaderNum st) of
-                             (True, DottedNum (n:_)) -> Just n
-                             _                       -> Nothing
-                  let num = case sLastFigureNum st of
-                       DottedNum [m,n]  ->
-                         case chapnum of
-                              Just m' | m' == m   -> DottedNum [m, n+1]
-                                      | otherwise -> DottedNum [m', 1]
-                              Nothing             -> DottedNum [1]
-                                                      -- shouldn't happen
-                       DottedNum [n]   ->
-                         case chapnum of
-                              Just m  -> DottedNum [m, 1]
-                              Nothing -> DottedNum [n + 1]
-                       _               ->
-                         case chapnum of
-                               Just n  -> DottedNum [n, 1]
-                               Nothing -> DottedNum [1]
-                  setState $
+                  num <- getNextNumber sLastFigureNum
+                  updateState $ \st ->
                     st{ sLastFigureNum = num
                       , sLabels = M.insert ident
                                  [Str (renderDottedNum num)] (sLabels st) }
           return $ Image attr' alt' (src, tit')
         go x = return x
 
+getNextNumber :: Monad m
+              => (LaTeXState -> DottedNum) -> LP m DottedNum
+getNextNumber getCurrentNum = do
+  st <- getState
+  let chapnum =
+        case (sHasChapters st, sLastHeaderNum st) of
+             (True, DottedNum (n:_)) -> Just n
+             _                       -> Nothing
+  return $
+    case getCurrentNum st of
+       DottedNum [m,n]  ->
+         case chapnum of
+              Just m' | m' == m   -> DottedNum [m, n+1]
+                      | otherwise -> DottedNum [m', 1]
+              Nothing             -> DottedNum [1]
+                                      -- shouldn't happen
+       DottedNum [n]   ->
+         case chapnum of
+              Just m  -> DottedNum [m, 1]
+              Nothing -> DottedNum [n + 1]
+       _               ->
+         case chapnum of
+               Just n  -> DottedNum [n, 1]
+               Nothing -> DottedNum [1]
+
+
 coloredBlock :: PandocMonad m => Text -> LP m Blocks
 coloredBlock stylename = try $ do
   skipopts
@@ -2379,10 +2386,19 @@ simpTable envname hasWidthParameter = try $ do
 addTableCaption :: PandocMonad m => Blocks -> LP m Blocks
 addTableCaption = walkM go
   where go (Table c als ws hs rs) = do
-          (mbcapt, _) <- sCaption <$> getState
-          return $ case mbcapt of
-               Just ils -> Table (toList ils) als ws hs rs
-               Nothing  -> Table c als ws hs rs
+          (mbcapt, mblabel) <- sCaption <$> getState
+          capt <- case (mbcapt, mblabel) of
+                   (Just ils, Nothing)  -> return $ toList ils
+                   (Just ils, Just lab) -> do
+                     num <- getNextNumber sLastTableNum
+                     updateState $ \st ->
+                       st{ sLastTableNum = num
+                         , sLabels = M.insert lab
+                                    [Str (renderDottedNum num)]
+                                    (sLabels st) }
+                     return $ toList ils -- add number??
+                   (Nothing, _)  -> return c
+          return $ Table capt als ws hs rs
         go x = return x
 
 
diff --git a/src/Text/Pandoc/Readers/LaTeX/Parsing.hs b/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
index a6836c3c1..4aa9976c9 100644
--- a/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
+++ b/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
@@ -120,6 +120,7 @@ data LaTeXState = LaTeXState{ sOptions       :: ReaderOptions
                             , sInTableCell   :: Bool
                             , sLastHeaderNum :: DottedNum
                             , sLastFigureNum :: DottedNum
+                            , sLastTableNum  :: DottedNum
                             , sLabels        :: M.Map Text [Inline]
                             , sHasChapters   :: Bool
                             , sToggles       :: M.Map Text Bool
@@ -141,6 +142,7 @@ defaultLaTeXState = LaTeXState{ sOptions       = def
                               , sInTableCell   = False
                               , sLastHeaderNum = DottedNum []
                               , sLastFigureNum = DottedNum []
+                              , sLastTableNum  = DottedNum []
                               , sLabels        = M.empty
                               , sHasChapters   = False
                               , sToggles       = M.empty
diff --git a/test/command/6137.md b/test/command/6137.md
new file mode 100644
index 000000000..9c5b71d0c
--- /dev/null
+++ b/test/command/6137.md
@@ -0,0 +1,31 @@
+```
+% pandoc -f latex -t native
+This reference to Table \ref{tbl:label} doesn't work.
+\begin{table}
+        \caption{This caption has no number.}\label{tbl:label}
+        \begin{tabular}{ l c r }
+          -------- & -------- & -------- \\
+          -------- & -------- & -------- \\
+        \end{tabular}
+\end{table}
+
+This reference to Figure \ref{fig:label} works fine.
+\begin{figure}
+        \includegraphics[width=\textwidth]{example.png}
+        \caption{A numbered caption, if I use pandoc-crossref.}\label{fig:label}
+\end{figure}
+^D
+[Para [Str "This",Space,Str "reference",Space,Str "to",Space,Str "Table",Space,Link ("",[],[("reference-type","ref"),("reference","tbl:label")]) [Str "1"] ("#tbl:label",""),Space,Str "doesn\8217t",Space,Str "work."]
+,Table [Str "This",Space,Str "caption",Space,Str "has",Space,Str "no",Space,Str "number.",Span ("",[],[("label","tbl:label")]) []] [AlignLeft,AlignCenter,AlignRight] [0.0,0.0,0.0]
+ [[]
+ ,[]
+ ,[]]
+ [[[Plain [Str "\8212\8212\8211"]]
+  ,[Plain [Str "\8212\8212\8211"]]
+  ,[Plain [Str "\8212\8212\8211"]]]
+ ,[[Plain [Str "\8212\8212\8211"]]
+  ,[Plain [Str "\8212\8212\8211"]]
+  ,[Plain [Str "\8212\8212\8211"]]]]
+,Para [Str "This",Space,Str "reference",Space,Str "to",Space,Str "Figure",Space,Link ("",[],[("reference-type","ref"),("reference","fig:label")]) [Str "1"] ("#fig:label",""),Space,Str "works",Space,Str "fine."]
+,Para [Image ("fig:label",[],[("width","\\textwidth")]) [Str "A",Space,Str "numbered",Space,Str "caption,",Space,Str "if",Space,Str "I",Space,Str "use",Space,Str "pandoc-crossref.",Span ("",[],[("label","fig:label")]) []] ("example.png","fig:")]]
+```