New approach to preventing image overflow in LaTeX (fixes #9660)

data/templates/default.latex

@@ -302,15 +302,17 @@ $endif$
 $if(graphics)$
 \usepackage{graphicx}
 \makeatletter
-\def\maxwidth{\ifdim\Gin@nat@width>\linewidth\linewidth\else\Gin@nat@width\fi}
-\def\maxheight{\ifdim\Gin@nat@height>\textheight\textheight\else\Gin@nat@height\fi}
-\makeatother
-% Scale images if necessary, so that they will not overflow the page
-% margins by default, and it is still possible to overwrite the defaults
-% using explicit options in \includegraphics[width, height, ...]{}
-\setkeys{Gin}{width=\maxwidth,height=\maxheight,keepaspectratio}
+\newsavebox\pandoc@box
+\newcommand*\pandocbounded[1]{% scales image to fit in text height/width
+  \sbox\pandoc@box{#1}%
+  \Gscale@div\@tempa{\textheight}{\dimexpr\ht\pandoc@box+\dp\pandoc@box\relax}%
+  \Gscale@div\@tempb{\linewidth}{\wd\pandoc@box}%
+  \ifdim\@tempb\p@<\@tempa\p@\let\@tempa\@tempb\fi% select the smaller of both
+  \ifdim\@tempa\p@<\p@\scalebox{\@tempa}{\usebox\pandoc@box}%
+  \else\usebox{\pandoc@box}%
+  \fi%
+}
 % Set default figure placement to htbp
-\makeatletter
 \def\fps@figure{htbp}
 \makeatother
 $endif$

src/Text/Pandoc/Writers/LaTeX.hs

@@ -1087,6 +1087,9 @@ inlineToLaTeX (Image attr@(_,_,kvs) _ (source, _)) = do
                                   [d <> "\\textheight"]
                                 _ -> []
       optList = showDim Width <> showDim Height <>
+                (case (dimension Height attr, dimension Width attr) of
+                  (Just _, Just _) -> []
+                  _ -> ["keepaspectratio"]) <>
                 maybe [] (\x -> ["page=" <> literal x]) (lookup "page" kvs) <>
                 maybe [] (\x -> ["trim=" <> literal x]) (lookup "trim" kvs) <>
                 maybe [] (const ["clip"]) (lookup "clip" kvs)
@@ -1100,8 +1103,11 @@ inlineToLaTeX (Image attr@(_,_,kvs) _ (source, _)) = do
   inHeading <- gets stInHeading
   return $
     (if inHeading then "\\protect" else "") <>
-      (if isSVG then "\\includesvg" else "\\includegraphics") <>
-    options <> braces (literal source'')
+    (case dimension Width attr `mplus` dimension Height attr of
+       Just _ -> id
+       Nothing -> ("\\pandocbounded" <>) . braces)
+      ((if isSVG then "\\includesvg" else "\\includegraphics") <>
+        options <> braces (literal source''))
 inlineToLaTeX (Note contents) = do
   setEmptyLine False
   externalNotes <- gets stExternalNotes

test/Tests/Writers/LaTeX.hs

@@ -70,7 +70,7 @@ tests = [ testGroup "code blocks"
             "\\begin{description}\n\\item[foo] ~ \n\\subsection{bar}\n\nbaz\n\\end{description}"
           , "containing image" =:
             header 1 (image "imgs/foo.jpg" "" (text "Alt text")) =?>
-            "\\section{\\texorpdfstring{\\protect\\includegraphics{imgs/foo.jpg}}{Alt text}}"
+            "\\section{\\texorpdfstring{\\protect\\pandocbounded{\\includegraphics[keepaspectratio]{imgs/foo.jpg}}}{Alt text}}"
           ]
         , testGroup "inline code"
           [ "struck out and highlighted" =:

test/command/3450.md

@@ -8,5 +8,5 @@
 % pandoc -fmarkdown-implicit_figures -t latex
 ![image](lalune.jpg){height=2em}
 ^D
-\includegraphics[width=\linewidth,height=2em]{lalune.jpg}
+\includegraphics[width=\linewidth,height=2em,keepaspectratio]{lalune.jpg}
 ```

test/command/5476.md

@@ -4,7 +4,7 @@
 ^D
 \begin{figure}
 \centering
-\includegraphics{test/lalune.jpg}
+\pandocbounded{\includegraphics[keepaspectratio]{test/lalune.jpg}}
 \caption[moon]{moon\footnotemark{}}
 \end{figure}
 \footnotetext{the moon}

test/command/7181.md

@@ -4,7 +4,7 @@
 ^D
 \begin{figure}
 \centering
-\includegraphics[page=13,trim=1cm,clip,width=4cm]{slides.pdf}
+\pandocbounded{\includegraphics[keepaspectratio,page=13,trim=1cm,clip,width=4cm]{slides.pdf}}
 \caption{Global frog population.}
 \end{figure}
 

test/command/9045.md

@@ -4,7 +4,7 @@
 ^D
 \begin{figure}
 \centering
-\includegraphics{there.jpg}
+\pandocbounded{\includegraphics[keepaspectratio]{there.jpg}}
 \caption{hi}\label{foo}
 \end{figure}
 ```

test/writer.latex

@@ -39,15 +39,17 @@
 \usepackage{xcolor}
 \usepackage{graphicx}
 \makeatletter
-\def\maxwidth{\ifdim\Gin@nat@width>\linewidth\linewidth\else\Gin@nat@width\fi}
-\def\maxheight{\ifdim\Gin@nat@height>\textheight\textheight\else\Gin@nat@height\fi}
-\makeatother
-% Scale images if necessary, so that they will not overflow the page
-% margins by default, and it is still possible to overwrite the defaults
-% using explicit options in \includegraphics[width, height, ...]{}
-\setkeys{Gin}{width=\maxwidth,height=\maxheight,keepaspectratio}
+\newsavebox\pandoc@box
+\newcommand*\pandocbounded[1]{% scales image to fit in text height/width
+  \sbox\pandoc@box{#1}%
+  \Gscale@div\@tempa{\textheight}{\dimexpr\ht\pandoc@box+\dp\pandoc@box\relax}%
+  \Gscale@div\@tempb{\linewidth}{\wd\pandoc@box}%
+  \ifdim\@tempb\p@<\@tempa\p@\let\@tempa\@tempb\fi% select the smaller of both
+  \ifdim\@tempa\p@<\p@\scalebox{\@tempa}{\usebox\pandoc@box}%
+  \else\usebox{\pandoc@box}%
+  \fi%
+}
 % Set default figure placement to htbp
-\makeatletter
 \def\fps@figure{htbp}
 \makeatother
 \ifLuaTeX
@@ -922,11 +924,12 @@ From ``Voyage dans la Lune'' by Georges Melies (1902):
 
 \begin{figure}
 \centering
-\includegraphics{lalune.jpg}
+\pandocbounded{\includegraphics[keepaspectratio]{lalune.jpg}}
 \caption{lalune}
 \end{figure}
 
-Here is a movie \includegraphics{movie.jpg} icon.
+Here is a movie \pandocbounded{\includegraphics[keepaspectratio]{movie.jpg}}
+icon.
 
 \begin{center}\rule{0.5\linewidth}{0.5pt}\end{center}