Escape ]]> in CDATA

Author: kornelski

Changelog.md

@@ -5,6 +5,7 @@
 * Merged `ParserConfig2` back into `ParserConfig`
 * Added option to the writer to pass through XML markup unmodified
 * `xml-analyze` binary has been moved to examples
+* Writer escapes `--` in comments and `]]>` in CDATA
 
 ## Version 0.8.27
 

src/writer/emitter.rs

@@ -400,11 +400,19 @@ impl Emitter {
         if self.config.cdata_to_characters {
             self.emit_characters(target, content)
         } else {
-            // TODO: escape ']]>' characters in CDATA as two adjacent CDATA blocks
             target.write_all(b"<![CDATA[")?;
-            target.write_all(content.as_bytes())?;
-            target.write_all(b"]]>")?;
 
+            for chunk in content.split_inclusive("]]>") {
+                let chunk_safe = chunk.strip_suffix("]]>");
+                let emit_escaped = chunk_safe.is_some();
+
+                target.write_all(chunk_safe.unwrap_or(chunk).as_bytes())?;
+                if emit_escaped {
+                    target.write_all(b"]]]]><![CDATA[>")?;
+                }
+            }
+
+            target.write_all(b"]]>")?;
             self.after_text();
 
             Ok(())

tests/event_writer.rs

@@ -286,6 +286,7 @@ fn accidental_cdata_suffix_in_characters_is_escaped() {
         unwrap_all! {
             w.write(XmlEvent::start_element("root"));
             w.write(XmlEvent::characters("[[a]]>b"));
+            w.write(XmlEvent::cdata("c]]>data"));
             w.write(XmlEvent::end_element())
         }
     }
@@ -296,6 +297,8 @@ fn accidental_cdata_suffix_in_characters_is_escaped() {
         assert!(matches!(r.next().unwrap(), XmlEvent::StartDocument { .. }));
         assert!(matches!(r.next().unwrap(), XmlEvent::StartElement { .. }));
         assert_eq!(r.next().unwrap(), XmlEvent::Characters("[[a]]>b".into()));
+        assert_eq!(r.next().unwrap(), XmlEvent::CData("c]]".into()));
+        assert_eq!(r.next().unwrap(), XmlEvent::CData(">data".into()));
         assert!(matches!(r.next().unwrap(), XmlEvent::EndElement { .. }));
         assert!(matches!(r.next().unwrap(), XmlEvent::EndDocument));
     }