Commit `9623fdfd99`

9623fdfd99c6ec5894bb7eeb5e85522f1cb207d5

parent: a097b4f379

Verified · cmc

cmc <hello@cleberg.net> · 2026-09-29 05:18 UTC

web: render TeX math in markdown and org as MathML

Ref #294

Layout: unified · split

.gitbay/wiki/Parity.org +4 −1

.gitbay/wiki/Users.org +15

	@@ -299,6 +299,21 @@ does on the repository page, with relative links resolved against the
299	file's directory; =source= in the file's action bar (or =?view=source=)	299	file's directory; =source= in the file's action bar (or =?view=source=)
300	shows the text instead. Other files show the text with highlighting.	300	shows the text instead. Other files show the text with highlighting.
301		301
		302	TeX math renders as MathML wherever markdown or org renders: READMEs,
		303	files, wiki pages, issue, merge request and release bodies, comments,
		304	and their previews. Markdown takes =$…$= inline and =$$…$$= for display,
		305	either inline or with the =$$= lines on their own. A =$= followed by a
		306	space, or a closing =$= preceded by a space or followed by a digit, is a
		307	dollar sign, so =$5 and $10= stays prose; =\$= is always one. Org takes
		308	=$…$=, =$$…$$=, =$…$=, =\[…\]= and =\begin{…}…\end{…}=. Code spans
		309	and blocks are left alone. The supported TeX is a subset (letters,
		310	numbers, operators, scripts, =\frac=, =\sqrt=, Greek and common symbols,
		311	=\left=/=\right=, accents, =\text=, the =\math…= fonts, matrices,
		312	=cases= and =aligned=; the full list heads =internal/texmath/texmath.go=).
		313	Anything outside it, including macros, colours and links, shows as
		314	source, as does an expression over 8 KiB or nested more than 64 deep.
		315	The CLI shows the source.
		316
302	* Organizations	317	* Organizations
303		318
304	Orgs share the owner namespace with users and own repositories at	319	Orgs share the owner namespace with users and own repositories at

CHANGELOG.org +5

   with ={items, next}=. =dashboard= gains =queries= for pinned ones; the
   web shows them on the dashboard and at =/<you>/-/queries=. An account
   keeps at most 50 saved queries, 10 pinned (#292).
+- TeX math renders server-side as MathML in markdown (=$…$=, =$$…$$=)
+  and org (=$…$=, =\(…\)=, =\[…\]=, LaTeX environments) wherever
+  markup renders, through a subset converter in =internal/texmath=;
+  the sanitizer admits exactly the elements and attributes it emits,
+  and anything outside the subset shows as source (#294).
 * v1.38.0 — 2026-09-29

internal/autolink/autolink.go +2 −2

	@@ -2,7 +2,7 @@
2	// to the repository's issues and merge requests, owner/name#N (and !N)	2	// to the repository's issues and merge requests, owner/name#N (and !N)
3	// across repositories, and @user to owner pages. It operates on the HTML	3	// across repositories, and @user to owner pages. It operates on the HTML
4	// produced by the markdown/org pipeline, walking text nodes with a real	4	// produced by the markdown/org pipeline, walking text nodes with a real
5	// parser so nothing inside <a>, <code>, or <pre> is ever touched, and only	5	// parser so nothing inside <a>, <code>, <pre> or <math> is ever touched, and only
6	// references that actually resolve become links.	6	// references that actually resolve become links.
7	package autolink	7	package autolink
8		8
	@@ -36,7 +36,7 @@ var (
36	)	36	)
37		37
38	// skip lists elements whose text must never be rewritten.	38	// skip lists elements whose text must never be rewritten.
39	var skip = map[string]bool{"a": true, "code": true, "pre": true, "script": true, "style": true}	39	var skip = map[string]bool{"a": true, "code": true, "math": true, "pre": true, "script": true, "style": true}
40		40
41	// Rewrite processes an HTML fragment, linking references relative to	41	// Rewrite processes an HTML fragment, linking references relative to
42	// defaultOwner/defaultName. On any parse failure the input is returned	42	// defaultOwner/defaultName. On any parse failure the input is returned

internal/httpd/math.go added +260

@@ -0,0 +1,260 @@
	1	package httpd
	2
	3	import (
	4	"bytes"
	5	"html/template"
	6	"regexp"
	7	"strings"
	8
	9	"github.com/microcosm-cc/bluemonday"
	10	"github.com/niklasfasching/go-org/org"
	11	"github.com/yuin/goldmark"
	12	"github.com/yuin/goldmark/ast"
	13	"github.com/yuin/goldmark/parser"
	14	"github.com/yuin/goldmark/renderer"
	15	"github.com/yuin/goldmark/text"
	16	"github.com/yuin/goldmark/util"
	17
	18	"gitbay.org/gitbay/internal/texmath"
	19	)
	20
	21	// TeX math renders server-side as MathML, which browsers display natively,
	22	// so the page needs no script and the CSP does not change (#294).
	23	//
	24	// The converter is internal/texmath rather than a library. The pure-Go
	25	// options were treeblood (MIT), which writes \color and \class arguments
	26	// into attributes unescaped, expands \def macros without a bound (a 180-byte
	27	// input produced 3 MB), did not finish 5000 nested braces in 30 seconds and
	28	// logs to stderr; goldmark-mathml, which runs Temml in a JavaScript VM; and
	29	// converters inside large typesetting modules. texmath covers a documented
	30	// subset, refuses everything else, and bounds input size and nesting.
	31
	32	// mathHTML renders one expression, or escapes its source when the converter
	33	// refuses it. The result passes through ugcPolicy even on the markdown path,
	34	// so the policy is the one statement of what math may emit.
	35	func mathHTML(tex, source string, display bool) (string, bool) {
	36	out, err := texmath.Convert(tex, display)
	37	if err != nil {
	38	return template.HTMLEscapeString(source), false
	39	}
	40	return ugcPolicy.Sanitize(out), true
	41	}
	42
	43	// allowMath admits exactly the MathML texmath emits: its elements, and each
	44	// attribute only on its element and only with the values it writes.
	45	func allowMath(p *bluemonday.Policy) {
	46	p.AllowElements(texmath.Elements...)
	47	p.AllowNoAttrs().OnElements(texmath.Elements...)
	48	for element, attrs := range texmath.Attrs {
	49	for name, value := range attrs {
	50	pattern := `^` + regexp.QuoteMeta(value) + `$`
	51	if value == "<length>" {
	52	pattern = `^-?[0-9]+(\.[0-9]+)?em$`
	53	}
	54	p.AllowAttrs(name).Matching(regexp.MustCompile(pattern)).OnElements(element)
	55	}
	56	}
	57	}
	58
	59	// Markdown: $…$ inline and $$…$$ display, inline or as a block.
	60
	61	var (
	62	kindMath = ast.NewNodeKind("Math")
	63	kindMathBlock = ast.NewNodeKind("MathBlock")
	64	)
	65
	66	type mathInline struct {
	67	ast.BaseInline
	68	tex string
	69	display bool
	70	}
	71
	72	func (n *mathInline) Kind() ast.NodeKind { return kindMath }
	73	func (n *mathInline) Dump(src []byte, level int) {
	74	ast.DumpHelper(n, src, level, map[string]string{"TeX": n.tex}, nil)
	75	}
	76
	77	type mathBlock struct {
	78	ast.BaseBlock
	79	tex []byte
	80	closed bool
	81	}
	82
	83	func (n *mathBlock) Kind() ast.NodeKind { return kindMathBlock }
	84	func (n *mathBlock) Dump(src []byte, level int) {
	85	ast.DumpHelper(n, src, level, map[string]string{"TeX": string(n.tex)}, nil)
	86	}
	87
	88	func isMathSpace(c byte) bool { return c == ' ' \|\| c == '\t' \|\| c == '\n' \|\| c == '\r' }
	89
	90	// mathInlineParser follows pandoc's rule so prices stay prose: the opening
	91	// $ has a non-space after it, and the closing $ a non-space before it and no
	92	// digit after it. "$5 and $10" is text. A backslash escapes the next byte.
	93	type mathInlineParser struct{}
	94
	95	func (mathInlineParser) Trigger() []byte { return []byte{'$'} }
	96
	97	func (mathInlineParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
	98	line, seg := block.PeekLine()
	99	if len(line) >= 2 && line[1] == '$' {
	100	body := line[2:]
	101	for i := 0; i+1 < len(body); i++ {
	102	if body[i] == '\\' {
	103	i++
	104	continue
	105	}
	106	if body[i] == '$' && body[i+1] == '$' {
	107	if i == 0 {
	108	break
	109	}
	110	block.Advance(i + 4)
	111	return &mathInline{tex: string(body[:i]), display: true}
	112	}
	113	}
	114	// Consume both dollars so the second does not open inline math.
	115	block.Advance(2)
	116	return ast.NewTextSegment(seg.WithStop(seg.Start + 2))
	117	}
	118	body := line[1:]
	119	if len(body) == 0 \|\| isMathSpace(body[0]) {
	120	return nil
	121	}
	122	for i := 0; i < len(body); i++ {
	123	switch body[i] {
	124	case '\\':
	125	i++
	126	case '$':
	127	if isMathSpace(body[i-1]) \|\| i+1 < len(body) && body[i+1] >= '0' && body[i+1] <= '9' {
	128	continue
	129	}
	130	block.Advance(i + 2)
	131	return &mathInline{tex: string(body[:i])}
	132	}
	133	}
	134	return nil
	135	}
	136
	137	// mathBlockParser opens on a line that is $$ alone, or $$…$$ whole, and
	138	// runs to the line that ends with $$.
	139	type mathBlockParser struct{}
	140
	141	func (mathBlockParser) Trigger() []byte { return []byte{'$'} }
	142
	143	func (mathBlockParser) Open(parent ast.Node, reader text.Reader, pc parser.Context) (ast.Node, parser.State) {
	144	line, _ := reader.PeekLine()
	145	pos := pc.BlockOffset()
	146	if pos < 0 \|\| !bytes.HasPrefix(line[pos:], []byte("$$")) {
	147	return nil, parser.NoChildren
	148	}
	149	rest := util.TrimRightSpace(line[pos+2:])
	150	n := &mathBlock{}
	151	switch {
	152	case len(rest) == 0:
	153	case len(rest) > 2 && bytes.HasSuffix(rest, []byte("$$")):
	154	n.tex, n.closed = rest[:len(rest)-2], true
	155	default:
	156	return nil, parser.NoChildren
	157	}
	158	reader.AdvanceToEOL()
	159	return n, parser.NoChildren
	160	}
	161
	162	func (mathBlockParser) Continue(node ast.Node, reader text.Reader, pc parser.Context) parser.State {
	163	n := node.(*mathBlock)
	164	if n.closed {
	165	return parser.Close
	166	}
	167	line, _ := reader.PeekLine()
	168	if line == nil {
	169	return parser.Close
	170	}
	171	trimmed := util.TrimRightSpace(line)
	172	if bytes.HasSuffix(trimmed, []byte("$$")) {
	173	n.tex = append(n.tex, trimmed[:len(trimmed)-2]...)
	174	n.closed = true
	175	reader.AdvanceToEOL()
	176	return parser.Close
	177	}
	178	n.tex = append(n.tex, line...)
	179	reader.AdvanceToEOL()
	180	return parser.Continue \| parser.NoChildren
	181	}
	182
	183	func (mathBlockParser) Close(ast.Node, text.Reader, parser.Context) {}
	184	func (mathBlockParser) CanInterruptParagraph() bool { return true }
	185	func (mathBlockParser) CanAcceptIndentedLine() bool { return false }
	186
	187	type mathRenderer struct{}
	188
	189	func (mathRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
	190	reg.Register(kindMath, func(w util.BufWriter, _ []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
	191	if entering {
	192	n := node.(*mathInline)
	193	delim := "$"
	194	if n.display {
	195	delim = "$$"
	196	}
	197	out, _ := mathHTML(n.tex, delim+n.tex+delim, n.display)
	198	_, _ = w.WriteString(out)
	199	}
	200	return ast.WalkSkipChildren, nil
	201	})
	202	reg.Register(kindMathBlock, func(w util.BufWriter, _ []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
	203	if !entering {
	204	return ast.WalkContinue, nil
	205	}
	206	n := node.(*mathBlock)
	207	source := "$$" + string(n.tex)
	208	if n.closed {
	209	source += "$$"
	210	}
	211	out, ok := mathHTML(string(n.tex), source, true)
	212	if !ok \|\| !n.closed {
	213	out = "<pre>" + template.HTMLEscapeString(source) + "</pre>"
	214	}
	215	_, _ = w.WriteString(out + "\n")
	216	return ast.WalkSkipChildren, nil
	217	})
	218	}
	219
	220	type mathExtension struct{}
	221
	222	func (mathExtension) Extend(m goldmark.Markdown) {
	223	m.Parser().AddOptions(
	224	parser.WithBlockParsers(util.Prioritized(mathBlockParser{}, 701)),
	225	parser.WithInlineParsers(util.Prioritized(mathInlineParser{}, 501)))
	226	m.Renderer().AddOptions(renderer.WithNodeRenderers(util.Prioritized(mathRenderer{}, 500)))
	227	}
	228
	229	// Org: go-org already parses $…$, $$…$$, $…$, \[…\] and \begin{…}…\end{…}
	230	// as LaTeX fragments, and \begin{…} on its own lines as a LaTeX block; it
	231	// writes them back out as text. These render them instead.
	232
	233	func (w *orgWriter) WriteLatexFragment(l org.LatexFragment) {
	234	tex := org.String(l.Content...)
	235	source := l.OpeningPair + tex + l.ClosingPair
	236	// go-org takes any $…$; org's own rule keeps "$5 and $10" prose.
	237	if l.OpeningPair == "$" && (tex == "" \|\| isMathSpace(tex[0]) \|\| isMathSpace(tex[len(tex)-1])) {
	238	w.WriteText(org.Text{Content: source, IsRaw: true})
	239	return
	240	}
	241	display := l.OpeningPair != "$" && l.OpeningPair != `\(`
	242	if strings.HasPrefix(l.OpeningPair, `\begin{`) {
	243	tex = source
	244	}
	245	out, ok := mathHTML(tex, source, display)
	246	if !ok {
	247	w.WriteText(org.Text{Content: source, IsRaw: true})
	248	return
	249	}
	250	w.WriteString(out)
	251	}
	252
	253	func (w *orgWriter) WriteLatexBlock(b org.LatexBlock) {
	254	tex := org.String(b.Content...)
	255	if out, ok := mathHTML(tex, tex, true); ok {
	256	w.WriteString(out + "\n")
	257	return
	258	}
	259	w.WriteString("<pre>" + template.HTMLEscapeString(tex) + "</pre>\n")
	260	}

internal/httpd/math_test.go added +183

@@ -0,0 +1,183 @@
	1	package httpd
	2
	3	import (
	4	"net/http/httptest"
	5	"strings"
	6	"testing"
	7	"time"
	8
	9	"gitbay.org/gitbay/internal/config"
	10	"gitbay.org/gitbay/internal/store"
	11	)
	12
	13	func TestMarkdownMath(t *testing.T) {
	14	cases := []struct {
	15	name, src string
	16	want []string
	17	not []string
	18	}{
	19	{"inline", "Euler: $e^{i\\pi}+1=0$.", []string{`<math><msup><mi>e</mi>`, `</math>.`}, nil},
	20	{"display inline", "so $$x^2$$ here", []string{`<math display="block"><msup>`}, nil},
	21	{"block", "text\n$$\n\\frac{a}{b}\n$$\nafter\n", []string{`<math display="block"><mfrac>`, `<p>after</p>`}, []string{"$$"}},
	22	{"one-line block", "$$x_1$$\n", []string{`<math display="block"><msub>`}, []string{"<p>"}},
	23	{"prices", "costs $5 and $10 today", []string{"costs $5 and $10 today"}, []string{"<math"}},
	24	{"space after open", "a $ x$ b", []string{"a $ x$ b"}, []string{"<math"}},
	25	{"space before close", "a $x $ b", []string{"a $x $ b"}, []string{"<math"}},
	26	{"digit after close", "$x$5", []string{"$x$5"}, []string{"<math"}},
	27	{"escaped dollars", `\$x\$`, []string{"$x$"}, []string{"<math"}},
	28	{"escaped dollar inside", `$a\$b$`, []string{`<mo>$</mo>`}, nil},
	29	{"code span", "`$x^2$`", []string{"<code>$x^2$</code>"}, []string{"<math"}},
	30	{"fenced code", "```\n$x^2$\n$$\ny\n$$\n```\n", []string{"$x^2$", "$$\ny\n$$"}, []string{"<math"}},
	31	{"indented code", " $x$\n", []string{"$x$"}, []string{"<math"}},
	32	{"invalid inline", `see $\frac{a$ here`, []string{`see $\frac{a$ here`}, []string{"<math"}},
	33	{"invalid block", "$$\n\\frac{\n$$\n", []string{"<pre tabindex=\"0\">$$\\frac{\n$$</pre>"}, []string{"<math"}},
	34	{"unclosed block", "$$\nx\n", []string{"<pre"}, []string{"<math"}},
	35	{"markup is escaped", "$\\text{<b>&</b>}$", []string{`<mtext><b>&</b></mtext>`}, []string{"<b>"}},
	36	}
	37	for _, c := range cases {
	38	out := string(ugcHTML(c.src, "md"))
	39	for _, w := range c.want {
	40	if !strings.Contains(out, w) {
	41	t.Errorf("%s: lacks %q:\n%s", c.name, w, out)
	42	}
	43	}
	44	for _, w := range c.not {
	45	if strings.Contains(out, w) {
	46	t.Errorf("%s: has %q:\n%s", c.name, w, out)
	47	}
	48	}
	49	}
	50	}
	51
	52	func TestOrgMath(t *testing.T) {
	53	cases := []struct {
	54	name, src string
	55	want []string
	56	not []string
	57	}{
	58	{"dollar", "Euler: $e^x$ here", []string{`<math><msup><mi>e</mi><mi>x</mi></msup></math> here`}, nil},
	59	{"paren", `a $x_1$ b`, []string{`<math><msub>`}, []string{`\(`}},
	60	{"bracket", `a \[x^2\] b`, []string{`<math display="block"><msup>`}, []string{`\[`}},
	61	{"double dollar", `a $$x$$ b`, []string{`<math display="block"><mi>x</mi></math>`}, nil},
	62	{"environment block", "\\begin{equation}\nx = \\frac{1}{2}\n\\end{equation}\n", []string{`<math display="block"><mrow><mi>x</mi><mo>=</mo><mfrac>`}, []string{`\begin`}},
	63	{"matrix block", "\\begin{pmatrix}\na & b \\\\\nc & d\n\\end{pmatrix}\n", []string{`<mtable><mtr><mtd><mi>a</mi></mtd>`}, nil},
	64	{"prices", "costs $5 and $10 today", []string{"costs $5 and $10 today"}, []string{"<math"}},
	65	{"verbatim", "=$x^2$= and ~$y$~", []string{"<code>$x^2$</code>", "<code>$y$</code>"}, []string{"<math"}},
	66	{"src block", "#+begin_src tex\n$x^2$\n#+end_src\n", []string{"<pre"}, []string{"<math"}},
	67	{"invalid", `see $\frac{a$ here`, []string{`see $\frac{a$ here`}, []string{"<math"}},
	68	{"invalid block", "\\begin{tabular}\nx\n\\end{tabular}\n", []string{`<pre tabindex="0">\begin{tabular}`}, []string{"<math"}},
	69	}
	70	for _, c := range cases {
	71	out := string(ugcHTML(c.src, "org"))
	72	for _, w := range c.want {
	73	if !strings.Contains(out, w) {
	74	t.Errorf("%s: lacks %q:\n%s", c.name, w, out)
	75	}
	76	}
	77	for _, w := range c.not {
	78	if strings.Contains(out, w) {
	79	t.Errorf("%s: has %q:\n%s", c.name, w, out)
	80	}
	81	}
	82	}
	83	}
	84
	85	// ugcPolicy admits the MathML texmath writes and nothing else, which is
	86	// what an .html README or org's raw export would otherwise carry through.
	87	func TestUGCPolicyMathML(t *testing.T) {
	88	hostile := `<math display="block" xmlns:xlink="http://www.w3.org/1999/xlink" style="x" onclick="x()">` +
	89	`<mi href="javascript:alert(1)" xlink:href="javascript:alert(2)" mathvariant="bold" style="color:red" onmouseover="x()">x</mi>` +
	90	`<mo stretchy="true" form="prefix">(</mo><mspace width="expression(alert(3))"></mspace><mspace width="1em"></mspace>` +
	91	`<semantics><annotation-xml encoding="text/html"><img src=x onerror="alert(4)"></annotation-xml></semantics>` +
	92	`<maction actiontype="statusline"><mi>y</mi></maction><mstyle mathcolor="red"><mi>z</mi></mstyle>` +
	93	`<mtext><style>*{}</style><script>alert(5)</script></mtext></math><math display="inline"></math>`
	94	out := ugcPolicy.Sanitize(hostile)
	95	for _, bad := range []string{"href", "xlink", "style", "onclick", "onmouseover", "onerror", "javascript",
	96	"annotation", "semantics", "maction", "mstyle", "mathcolor", "script", "expression",
	97	`mathvariant="bold"`, `stretchy="true"`, "form=", `display="inline"`} {
	98	if strings.Contains(out, bad) {
	99	t.Errorf("sanitized MathML keeps %q:\n%s", bad, out)
	100	}
	101	}
	102	for _, good := range []string{`<math display="block">`, `<mspace width="1em">`, "<mi>x</mi>", "<mi>y</mi>"} {
	103	if !strings.Contains(out, good) {
	104	t.Errorf("sanitized MathML lacks %q:\n%s", good, out)
	105	}
	106	}
	107	}
	108
	109	// Hostile TeX is refused and shown as escaped source, in bounded time and
	110	// size, on both syntaxes.
	111	func TestHostileMath(t *testing.T) {
	112	long := strings.Repeat(`x+`, 1<<19) // 1 MiB in one expression
	113	deep := strings.Repeat("{", 50000) + "x" + strings.Repeat("}", 50000)
	114	for _, tex := range []string{
	115	`\href{javascript:alert(1)}{x}`, `\url{javascript:alert(1)}`, `\style{color:red}{x}`,
	116	`\color{red" onmouseover="alert(1)}{x}`, `\class{a"b}{x}`, `\def\a{\a\a}\a`,
	117	`\text{</math><script>alert(1)</script>}`, `\text{<img src=x onerror=alert(1)>}`,
	118	deep, long, strings.Repeat(`\sqrt{`, 10000) + "x",
	119	} {
	120	for _, doc := range []struct{ src, format string }{
	121	{"$" + tex + "$", "md"}, {"$$\n" + tex + "\n$$\n", "md"},
	122	{`$` + tex + `$`, "org"}, {"\\[" + tex + "\\]", "org"},
	123	} {
	124	start := time.Now()
	125	out := string(ugcHTML(doc.src, doc.format))
	126	if d := time.Since(start); d > 2*time.Second {
	127	t.Errorf("%.30q (%s) took %v", tex, doc.format, d)
	128	}
	129	if len(out) > 8*len(doc.src)+1024 {
	130	t.Errorf("%.30q (%s): %d bytes out for %d in", tex, doc.format, len(out), len(doc.src))
	131	}
	132	for _, bad := range []string{"<script", "<img", `href="`, `onmouseover="`, `style="`, `class="a`} {
	133	if strings.Contains(out, bad) {
	134	t.Errorf("%.30q (%s) emits %q:\n%.300s", tex, doc.format, bad, out)
	135	}
	136	}
	137	}
	138	}
	139	// A refused \text keeps its payload as visible text, escaped.
	140	out := string(ugcHTML(`$\href{javascript:alert(1)}{x}$`, "md"))
	141	if !strings.Contains(out, `$\href{javascript:alert(1)}{x}$`) \|\| strings.Contains(out, "<math") \|\| strings.Contains(out, "<a") {
	142	t.Errorf("refused \\href: %s", out)
	143	}
	144	}
	145
	146	// The issue page renders its body's math through the shared path, and
	147	// autolinking leaves text inside <math> alone.
	148	func TestIssuePageRendersMath(t *testing.T) {
	149	st, err := store.Open(":memory:")
	150	if err != nil {
	151	t.Fatal(err)
	152	}
	153	defer st.Close()
	154	if err := st.MigrateUp(); err != nil {
	155	t.Fatal(err)
	156	}
	157	uid, err := st.CreateUser("alice", false)
	158	if err != nil {
	159	t.Fatal(err)
	160	}
	161	repoID, err := st.CreateRepo("user", uid, "app", "public")
	162	if err != nil {
	163	t.Fatal(err)
	164	}
	165	if _, err := st.CreateIssue(repoID, uid, "math", `Area is $\pi r^2$, see $\text{#1}$.`, "md"); err != nil {
	166	t.Fatal(err)
	167	}
	168	cfg := config.Default()
	169	cfg.Web.Mode = "accounts"
	170	s := New(cfg, st, nil)
	171	rr := httptest.NewRecorder()
	172	s.Handler().ServeHTTP(rr, httptest.NewRequest("GET", "/alice/app/issues/1", nil))
	173	if rr.Code != 200 {
	174	t.Fatalf("status %d", rr.Code)
	175	}
	176	body := rr.Body.String()
	177	if !strings.Contains(body, `<math><mi>π</mi><msup><mi>r</mi><mn>2</mn></msup></math>`) {
	178	t.Errorf("no MathML in the issue page:\n%s", body)
	179	}
	180	if !strings.Contains(body, `<mtext>#1</mtext>`) {
	181	t.Errorf("autolink rewrote text inside <math>:\n%s", body)
	182	}
	183	}

internal/httpd/web.go +4 −3

 // markdown is the shared renderer: GFM (tables, strikethrough, autolinks,
 // task lists) on top of CommonMark, with class-based fence highlighting
-// (the palette lives in the stylesheet, per scheme). Raw HTML is still
+// (the palette lives in the stylesheet, per scheme), and TeX math as
-// dropped.
+// MathML (math.go). Raw HTML is still dropped.
 // Headings carry ids so a README or wiki section can be linked to, the
 // way org headings already are (#132).
 var markdown = goldmark.New(
 	goldmark.WithParserOptions(parser.WithAutoHeadingID()),
-	goldmark.WithExtensions(extension.GFM,
+	goldmark.WithExtensions(extension.GFM, mathExtension{},
 		highlighting.NewHighlighting(highlighting.WithFormatOptions(html.WithClasses(true)))))
 // fenceHighlight renders one code block with chroma classes, for org and
 	p.AllowAttrs("class").
 		Matching(regexp.MustCompile(`^(chroma|[a-z0-9]{1,3})( (chroma|[a-z0-9]{1,3}))*$`)).
 		OnElements("span", "pre", "code", "div")
+	allowMath(p)
 	return p
 }()

	@@ -57,6 +57,7 @@ browser-only and the iOS build screen unable to say more than the log.
57	\| request a review \| yes \| yes \| yes \|	57	\| request a review \| yes \| yes \| yes \|
58	\| choose body markup \| yes \| yes \| yes \|	58	\| choose body markup \| yes \| yes \| yes \|
59	\| preview body markup \| n/a \| yes \| no \|	59	\| preview body markup \| n/a \| yes \| no \|
		60	\| TeX math as MathML \| n/a \| yes \| no \|
60	\| stacked merge requests \| yes \| yes \| yes \|	61	\| stacked merge requests \| yes \| yes \| yes \|
61	\| revisions \| yes \| yes \| yes \|	62	\| revisions \| yes \| yes \| yes \|
62	\| range-diff \| yes \| yes \| yes \|	63	\| range-diff \| yes \| yes \| yes \|
	@@ -125,6 +126,7 @@ reviews, since an approval was of the diff against the old branch.
125	\| labels: list, colour \| yes \| yes \| yes \|	126	\| labels: list, colour \| yes \| yes \| yes \|
126	\| choose body markup \| yes \| yes \| yes \|	127	\| choose body markup \| yes \| yes \| yes \|
127	\| preview body markup \| n/a \| yes \| no \|	128	\| preview body markup \| n/a \| yes \| no \|
		129	\| TeX math as MathML \| n/a \| yes \| no \|
128	\| issue templates \| yes \| yes \| yes \|	130	\| issue templates \| yes \| yes \| yes \|
129	\| milestone create, close, reopen \| yes \| yes \| yes \|	131	\| milestone create, close, reopen \| yes \| yes \| yes \|
130	\| org labels: set, list, remove \| yes \| yes \| yes \|	132	\| org labels: set, list, remove \| yes \| yes \| yes \|
	@@ -155,7 +157,8 @@ every surface now offers the choice: the web's create forms, and the iOS
155	composer on create, edit and comment. An edit starts on the format its	157	composer on create, edit and comment. An edit starts on the format its
156	body was stored in, since starting elsewhere would silently reinterpret	158	body was stored in, since starting elsewhere would silently reinterpret
157	it on the next save. Diff-line comments have no format column and are	159	it on the next save. Diff-line comments have no format column and are
158	always markdown.	160	always markdown. TeX math in either format renders as MathML on the
		161	web (#294); the terminal shows the source, so the CLI row is =n/a=.
159		162
160	Every web form that takes markup has a Preview button beside its own	163	Every web form that takes markup has a Preview button beside its own
161	submit: issue and merge request create, their edit and comment boxes,	164	submit: issue and merge request create, their edit and comment boxes,

Commit 9623fdfd99

Commit `9623fdfd99`