From 198ce0cde99731680b62294a7dff1b218b29bd4d Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Fri, 22 Jan 2021 20:49:41 -0800
Subject: ImageSize:   use viewBox for svg if no length, width.

This change allows pandoc to extract size information
from more SVGs.  Closes #7045.
---
 src/Text/Pandoc/ImageSize.hs |  8 ++++++--
 test/command/svg.md          | 30 ++++++++++++++----------------
 2 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/src/Text/Pandoc/ImageSize.hs b/src/Text/Pandoc/ImageSize.hs
index 098c16721..e19958f6a 100644
--- a/src/Text/Pandoc/ImageSize.hs
+++ b/src/Text/Pandoc/ImageSize.hs
@@ -328,12 +328,16 @@ getSize img =
 svgSize :: WriterOptions -> ByteString -> Maybe ImageSize
 svgSize opts img = do
   doc <- Xml.parseXMLDoc $ UTF8.toString img
+  let viewboxSize = do
+        vb <- Xml.findAttrBy (== Xml.QName "viewBox" Nothing Nothing) doc
+        [_,_,w,h] <- mapM safeRead (T.words (T.pack vb))
+        return (w,h)
   let dpi = fromIntegral $ writerDpi opts
   let dirToInt dir = do
         dim <- Xml.findAttrBy (== Xml.QName dir Nothing Nothing) doc >>= lengthToDim . T.pack
         return $ inPixel opts dim
-  w <- dirToInt "width"
-  h <- dirToInt "height"
+  w <- dirToInt "width" <|> (fst <$> viewboxSize)
+  h <- dirToInt "height" <|> (snd <$> viewboxSize)
   return ImageSize {
     pxX  = w
   , pxY  = h
diff --git a/test/command/svg.md b/test/command/svg.md
index 57506570b..4ba836b20 100644
--- a/test/command/svg.md
+++ b/test/command/svg.md
@@ -36,28 +36,27 @@
 % pandoc -f latex -t icml
 \includegraphics{command/SVG_logo.svg}
 ^D
-[WARNING] Could not determine image size for 'command/SVG_logo.svg': could not determine SVG size
 <ParagraphStyleRange AppliedParagraphStyle="ParagraphStyle/Paragraph">
   <CharacterStyleRange AppliedCharacterStyle="$ID/NormalCharacterStyle">
-    <Rectangle Self="uec" StrokeWeight="0" ItemTransform="1 0 0 1 150 -100">
+    <Rectangle Self="uec" StrokeWeight="0" ItemTransform="1 0 0 1 37.5 -37.5">
       <Properties>
         <PathGeometry>
           <GeometryPathType PathOpen="false">
             <PathPointArray>
-              <PathPointType Anchor="-150 -100" LeftDirection="-150 -100" RightDirection="-150 -100" />
-              <PathPointType Anchor="-150 100" LeftDirection="-150 100" RightDirection="-150 100" />
-              <PathPointType Anchor="150 100" LeftDirection="150 100" RightDirection="150 100" />
-              <PathPointType Anchor="150 -100" LeftDirection="150 -100" RightDirection="150 -100" />
+              <PathPointType Anchor="-37.5 -37.5" LeftDirection="-37.5 -37.5" RightDirection="-37.5 -37.5" />
+              <PathPointType Anchor="-37.5 37.5" LeftDirection="-37.5 37.5" RightDirection="-37.5 37.5" />
+              <PathPointType Anchor="37.5 37.5" LeftDirection="37.5 37.5" RightDirection="37.5 37.5" />
+              <PathPointType Anchor="37.5 -37.5" LeftDirection="37.5 -37.5" RightDirection="37.5 -37.5" />
             </PathPointArray>
           </GeometryPathType>
         </PathGeometry>
       </Properties>
-      <Image Self="ue6" ItemTransform="1 0 0 1 -150 -100">
+      <Image Self="ue6" ItemTransform="1 0 0 1 -37.5 -37.5">
         <Properties>
           <Profile type="string">
             $ID/Embedded
           </Profile>
-          <GraphicBounds Left="0" Top="0" Right="300" Bottom="200" />
+          <GraphicBounds Left="0" Top="0" Right="75" Bottom="75" />
         </Properties>
         <Link Self="ueb" LinkResourceURI="file:command/SVG_logo.svg" />
       </Image>
@@ -70,28 +69,27 @@
 % pandoc -f latex -t icml
 \includegraphics{command/SVG_logo-without-xml-declaration.svg}
 ^D
-[WARNING] Could not determine image size for 'command/SVG_logo-without-xml-declaration.svg': could not determine SVG size
 <ParagraphStyleRange AppliedParagraphStyle="ParagraphStyle/Paragraph">
   <CharacterStyleRange AppliedCharacterStyle="$ID/NormalCharacterStyle">
-    <Rectangle Self="uec" StrokeWeight="0" ItemTransform="1 0 0 1 150 -100">
+    <Rectangle Self="uec" StrokeWeight="0" ItemTransform="1 0 0 1 37.5 -37.5">
       <Properties>
         <PathGeometry>
           <GeometryPathType PathOpen="false">
             <PathPointArray>
-              <PathPointType Anchor="-150 -100" LeftDirection="-150 -100" RightDirection="-150 -100" />
-              <PathPointType Anchor="-150 100" LeftDirection="-150 100" RightDirection="-150 100" />
-              <PathPointType Anchor="150 100" LeftDirection="150 100" RightDirection="150 100" />
-              <PathPointType Anchor="150 -100" LeftDirection="150 -100" RightDirection="150 -100" />
+              <PathPointType Anchor="-37.5 -37.5" LeftDirection="-37.5 -37.5" RightDirection="-37.5 -37.5" />
+              <PathPointType Anchor="-37.5 37.5" LeftDirection="-37.5 37.5" RightDirection="-37.5 37.5" />
+              <PathPointType Anchor="37.5 37.5" LeftDirection="37.5 37.5" RightDirection="37.5 37.5" />
+              <PathPointType Anchor="37.5 -37.5" LeftDirection="37.5 -37.5" RightDirection="37.5 -37.5" />
             </PathPointArray>
           </GeometryPathType>
         </PathGeometry>
       </Properties>
-      <Image Self="ue6" ItemTransform="1 0 0 1 -150 -100">
+      <Image Self="ue6" ItemTransform="1 0 0 1 -37.5 -37.5">
         <Properties>
           <Profile type="string">
             $ID/Embedded
           </Profile>
-          <GraphicBounds Left="0" Top="0" Right="300" Bottom="200" />
+          <GraphicBounds Left="0" Top="0" Right="75" Bottom="75" />
         </Properties>
         <Link Self="ueb" LinkResourceURI="file:command/SVG_logo-without-xml-declaration.svg" />
       </Image>
-- 
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