From 26aed11841aebf63d1a496e32364b380fdd45175 Mon Sep 17 00:00:00 2001
From: Mark <mark.quach1234@gmail.com>
Date: Tue, 7 Jul 2026 02:36:08 +1000
Subject: [PATCH] Fix false math-mode warning for \tag* with math content

\tag*{...} (amsmath's unnumbered tag) incorrectly triggered an "open
inline math \( used inside existing math mode" warning when its
argument contained inline math, e.g. \tag*{\(\dagger\)} or
\tag*{$abc$}. \tag{...} without the star already worked.

The linter marks \tag's argument group as text-mode so nested math
delimiters are allowed, but the literal * between \tag and { was
tokenized separately and reset that flag before the argument group
was reached. \tag now consumes an immediately following * so the
text-mode flag survives to the argument group.
---
 .../languages/latex/linter/latex-linter.worker.ts  | 14 +++++++++++++-
 .../languages/latex/latex-linter.test.ts           | 12 ++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/services/web/frontend/js/features/source-editor/languages/latex/linter/latex-linter.worker.ts b/services/web/frontend/js/features/source-editor/languages/latex/linter/latex-linter.worker.ts
index bb8589406b..20e1e9860c 100644
--- a/services/web/frontend/js/features/source-editor/languages/latex/linter/latex-linter.worker.ts
+++ b/services/web/frontend/js/features/source-editor/languages/latex/linter/latex-linter.worker.ts
@@ -1107,12 +1107,24 @@ const InterpretTokens = function (
         seq === 'intertext' ||
         seq === 'shortintertext' ||
         seq === 'textnormal' ||
-        seq === 'tag' ||
         seq === 'reflectbox' ||
         seq === 'textrm'
       ) {
         // next group will be in text mode regardless
         nextGroupMathMode = false
+      } else if (seq === 'tag') {
+        // next group will be in text mode regardless
+        nextGroupMathMode = false
+        // \tag* (unnumbered tag) - skip over the '*' so it doesn't reset
+        // nextGroupMathMode before the argument group is reached
+        const nextToken = Tokens[i + 1]
+        if (
+          nextToken &&
+          nextToken[1] === 'Text' &&
+          text.substring(nextToken[2], nextToken[3]) === '*'
+        ) {
+          i = i + 1
+        }
       } else if (seq === 'tikz') {
         // try to read any optional params [BAR]...., advance if found
         const newPos = readOptionalGeneric(TokeniseResult, i)
diff --git a/services/web/test/frontend/features/source-editor/languages/latex/latex-linter.test.ts b/services/web/test/frontend/features/source-editor/languages/latex/latex-linter.test.ts
index ea4c7e8e15..a6a78762c9 100644
--- a/services/web/test/frontend/features/source-editor/languages/latex/latex-linter.test.ts
+++ b/services/web/test/frontend/features/source-editor/languages/latex/latex-linter.test.ts
@@ -350,6 +350,18 @@ describe('LatexLinter', function () {
     assert.equal(errors.length, 0)
   })
 
+  it('should accept math tag* commands', function () {
+    const { errors } = Parse(
+      '\\begin{align}\n\\pi=3 \\tag*{\\(\\dagger\\)}\n\\end{align}\n'
+    )
+    assert.equal(errors.length, 0)
+  })
+
+  it('should accept math tag* commands with $ math mode', function () {
+    const { errors } = Parse('$\\tag*{$abc$}$\n')
+    assert.equal(errors.length, 0)
+  })
+
   it('should accept math \\def commands', function () {
     const { errors } = Parse(
       '\\def\\peb[#1]{{\\left\\lfloor #1\\right\\rfloor}}'