internal/graph: escape file and title strings written to dot

internal/graph/dotgraph.go

@@ -110,7 +110,7 @@ func (b *builder) start() {
 	if b.config.Title != "" {
 		graphname = b.config.Title
 	}
-	fmt.Fprintln(b, `digraph "`+graphname+`" {`)
+	fmt.Fprintln(b, `digraph "`+escapeForDot(graphname)+`" {`)
 	fmt.Fprintln(b, `node [style=filled fillcolor="#f8f8f8"]`)
 }
 
@@ -132,7 +132,7 @@ func (b *builder) addLegend() {
 		fmt.Fprintf(b, ` URL="%s" target="_blank"`, b.config.LegendURL)
 	}
 	if b.config.Title != "" {
-		fmt.Fprintf(b, ` tooltip="%s"`, b.config.Title)
+		fmt.Fprintf(b, ` tooltip="%s"`, escapeForDot(b.config.Title))
 	}
 	fmt.Fprintf(b, "] }\n")
 }
@@ -390,7 +390,10 @@ func multilinePrintableName(info *NodeInfo) string {
 	infoCopy.Name = strings.ReplaceAll(infoCopy.Name, "[...]", "[…]")
 	infoCopy.Name = strings.ReplaceAll(infoCopy.Name, ".", `\n`)
 	if infoCopy.File != "" {
-		infoCopy.File = filepath.Base(infoCopy.File)
+		infoCopy.File = escapeForDot(filepath.Base(infoCopy.File))
+	}
+	if infoCopy.Objfile != "" {
+		infoCopy.Objfile = escapeForDot(filepath.Base(infoCopy.Objfile))
 	}
 	return strings.Join(infoCopy.NameComponents(), `\n`) + `\n`
 }

internal/graph/dotgraph_test.go

@@ -141,13 +141,29 @@ func TestComposeWithStandardGraphAndURL(t *testing.T) {
 func TestComposeWithNamesThatNeedEscaping(t *testing.T) {
 	g := baseGraph()
 	a, c := baseAttrsAndConfig()
-	g.Nodes[0].Info = NodeInfo{Name: `var"src"`}
-	g.Nodes[1].Info = NodeInfo{Name: `var"#dest#"`}
+	g.Nodes[0].Info = NodeInfo{Name: `var"src"`, File: `/src/file"name.go`, Lineno: 10}
+	g.Nodes[1].Info = NodeInfo{Address: 0x10, Objfile: `/lib/obj"file.so`}
+	c.Title = `test"title`
+	c.Labels = []string{"legend", `label"text`}
 
 	var buf bytes.Buffer
 	ComposeDot(&buf, g, a, c)
-
-	compareGraphs(t, buf.Bytes(), "compose7.dot")
+	got := buf.String()
+
+	for _, tc := range []struct{ raw, escaped string }{
+		{`var"src"`, `var\"src\"`},
+		{`file"name.go`, `file\"name.go`},
+		{`obj"file.so`, `obj\"file.so`},
+		{`test"title`, `test\"title`},
+		{`label"text`, `label\"text`},
+	} {
+		if strings.Contains(got, tc.raw) {
+			t.Errorf("unescaped %q in dot output:\n%s", tc.raw, got)
+		}
+		if !strings.Contains(got, tc.escaped) {
+			t.Errorf("escaped %q not found in dot output:\n%s", tc.escaped, got)
+		}
+	}
 }
 
 func TestComposeWithCommentsWithNewlines(t *testing.T) {