Fix smart quotes in PDF outline (#3790)

crates/typst/src/text/smartquote.rs

@@ -2,7 +2,9 @@ use ecow::EcoString;
 use unicode_segmentation::UnicodeSegmentation;
 
 use crate::diag::{bail, StrResult};
-use crate::foundations::{array, cast, dict, elem, Array, Dict, FromValue, Smart, Str};
+use crate::foundations::{
+    array, cast, dict, elem, Array, Dict, FromValue, Packed, PlainText, Smart, Str,
+};
 use crate::layout::Dir;
 use crate::syntax::is_newline;
 use crate::text::{Lang, Region};
@@ -26,7 +28,7 @@ use crate::text::{Lang, Region};
 /// # Syntax
 /// This function also has dedicated syntax: The normal quote characters
 /// (`'` and `"`). Typst automatically makes your quotes smart.
-#[elem(name = "smartquote")]
+#[elem(name = "smartquote", PlainText)]
 pub struct SmartQuoteElem {
     /// Whether this should be a double quote.
     #[default(true)]
@@ -85,6 +87,16 @@ pub struct SmartQuoteElem {
     pub quotes: Smart<SmartQuoteDict>,
 }
 
+impl PlainText for Packed<SmartQuoteElem> {
+    fn plain_text(&self, text: &mut EcoString) {
+        if self.double.unwrap_or(true) {
+            text.push_str("\"");
+        } else {
+            text.push_str("'");
+        }
+    }
+}
+
 /// State machine for smart quote substitution.
 #[derive(Debug, Clone)]
 pub struct SmartQuoter {

tests/typ/bugs/3662-pdf-smartquotes.typ

@@ -0,0 +1,12 @@
+// Smart quotes were not appearing in the PDF outline, because they didn't
+// implement `PlainText`
+// https://github.com/typst/typst/issues/3662
+
+---
+= It's "Unnormal Heading"
+= It’s “Normal Heading”
+
+#set smartquote(enabled: false)
+= It's "Unnormal Heading"
+= It's 'single quotes'
+= It’s “Normal Heading”