From 912bfa5e2e3f5c74eb125dfc19404f67c61ca58b Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Tue, 9 Jun 2026 13:06:17 +0200
Subject: [PATCH] Use starmath for math in ODT.

This improves appearance and editability of math in ODT.

Depends on dev version of texmath.

The main code changes are due to @jdpipe (#11470).
---
 cabal.project                  |  5 ++++
 src/Text/Pandoc/Writers/ODT.hs | 51 ++++++++++++++++++++++++++++++++--
 stack.yaml                     |  3 +-
 3 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/cabal.project b/cabal.project
index a0152146d..c995aed34 100644
--- a/cabal.project
+++ b/cabal.project
@@ -8,6 +8,11 @@ constraints: skylighting-format-blaze-html >= 0.1.2,
              crypton >= 1.1.1,
              doclayout >= 0.5.0.3
 
+source-repository-package
+  type: git
+  location: https://github.com/jgm/texmath.git
+  tag: 170899673ee31de9096e178605e8da31a36e4185
+
 package pandoc
   flags: +embed_data_files +http
 
diff --git a/src/Text/Pandoc/Writers/ODT.hs b/src/Text/Pandoc/Writers/ODT.hs
index 38d89535f..b25471678 100644
--- a/src/Text/Pandoc/Writers/ODT.hs
+++ b/src/Text/Pandoc/Writers/ODT.hs
@@ -350,11 +350,15 @@ transformPicMath opts (Image attr@(id', cls, _) lab (src,t)) = catchError
 transformPicMath _ (Math t math) = do
   entries <- gets stEntries
   let dt = if t == InlineMath then DisplayInline else DisplayBlock
-  case writeMathML dt <$> readTeX math of
+  case readTeX math of
        Left  _ -> return $ Math t math
-       Right r -> do
+       Right exps -> do
          let conf = XL.useShortEmptyTags (const False) XL.defaultConfigPP
-         let mathml = XL.ppcTopElement conf r
+         let starMath =
+               writeStarMath dt exps <> "\n" <> starMathCommentFromTeX math
+         let mathmlElement =
+               addStarMathAnnotation starMath (writeMathML dt exps)
+         let mathml = XL.ppcTopElement conf mathmlElement
          epochtime <- floor `fmap` lift P.getPOSIXTime
          let dirname = "Formula-" ++ show (length entries) ++ "/"
          let fname = dirname ++ "content.xml"
@@ -379,6 +383,47 @@ transformPicMath _ (Math t math) = do
 
 transformPicMath _ x = return x
 
+starMathCommentFromTeX :: T.Text -> T.Text
+starMathCommentFromTeX tex =
+  case T.lines normalized of
+    []       -> "%% TeX:"
+    (l : ls) ->
+      T.intercalate "\n" (("%% TeX: " <> l) : map ("%% " <>) ls)
+ where
+  normalized = T.replace "\r\n" "\n" (T.replace "\r" "\n" tex)
+
+addStarMathAnnotation :: T.Text -> XL.Element -> XL.Element
+addStarMathAnnotation starMath e =
+  case XL.elContent e of
+    [XL.Elem sem] | XL.qName (XL.elName sem) == "semantics" ->
+      e { XL.elContent = [XL.Elem (withAnnotation sem)] }
+    _ ->
+      e { XL.elContent = [XL.Elem (mkSemantics (XL.elContent e))] }
+ where
+  mkSemantics cs =
+    XL.Element (mkMathQName "semantics") [] (cs ++ [XL.Elem annotation]) Nothing
+
+  withAnnotation sem =
+    sem { XL.elContent =
+            filter (not . isStarMathAnnotation) (XL.elContent sem)
+            ++ [XL.Elem annotation] }
+
+  annotation =
+    XL.Element (mkMathQName "annotation")
+      [XL.Attr (XL.QName "encoding" Nothing Nothing) "StarMath 5.0"]
+      [XL.Text (XL.CData XL.CDataText (T.unpack starMath) Nothing)]
+      Nothing
+
+  isStarMathAnnotation (XL.Elem el) =
+    XL.qName (XL.elName el) == "annotation" &&
+    any (\a -> XL.qName (XL.attrKey a) == "encoding"
+               && XL.attrVal a == "StarMath 5.0")
+        (XL.elAttribs el)
+  isStarMathAnnotation _ = False
+
+  mkMathQName n =
+    XL.QName n (XL.qURI $ XL.elName e) (XL.qPrefix $ XL.elName e)
+
 documentSettings :: Bool -> B.ByteString
 documentSettings isTextMode = fromStringLazy $ render Nothing
     $ text "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
diff --git a/stack.yaml b/stack.yaml
index bb40e3ffd..e488f40b9 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -32,8 +32,9 @@ extra-deps:
 - pandoc-types-1.23.1.2
 - typst-symbols-0.2
 - typst-0.10
-- texmath-0.13.1.2
 - emojis-0.1.5
+- git: https://github.com/jgm/texmath.git
+  commit: 170899673ee31de9096e178605e8da31a36e4185
 
 ghc-options:
    "$locals": -fhide-source-paths -Wno-missing-home-modules