fix: correctly escape and unescape text

src/parser/parsed_string.rs

@@ -12,17 +12,42 @@ impl ParseString<'_> {
             Cow::Owned(ref s) => ParseString(Cow::Owned(s.clone())),
         }
     }
+
     pub fn into_owned(self) -> ParseString<'static> {
         match self.0 {
             Cow::Borrowed(s) => ParseString(Cow::Owned(s.to_owned())),
             Cow::Owned(s) => ParseString(Cow::Owned(s)),
         }
     }
+
     pub fn as_str(&self) -> &str {
         self.0.as_ref()
     }
 }
 
+impl<'a> ParseString<'a> {
+    pub fn unescape_text(self) -> ParseString<'a> {
+        if self.0.contains(r#"\\"#)
+            || self.0.contains(r#"\,"#)
+            || self.0.contains(r#"\;"#)
+            || self.0.contains(r#"\:"#)
+            || self.0.contains(r#"\N"#)
+            || self.0.contains(r#"\n"#)
+        {
+            self.0
+                .replace(r#"\\"#, r#"\"#)
+                .replace(r#"\,"#, ",")
+                .replace(r#"\;"#, ";")
+                .replace(r#"\:"#, ":")
+                .replace(r#"\N"#, "\n")
+                .replace(r#"\n"#, "\n")
+                .into()
+        } else {
+            self
+        }
+    }
+}
+
 impl PartialEq<Self> for ParseString<'_> {
     fn eq(&self, rhs: &Self) -> bool {
         self.as_ref() == rhs.as_ref()

src/parser/properties.rs

@@ -166,12 +166,22 @@ fn test_property() {
     );
 
     // TODO: newlines followed by spaces must be ignored
+    assert_parser!(
+        property,
+        "KEY4;foo=bar:VALUE\\n newline separated\n",
+        Property {
+            name: "KEY4".into(),
+            val: "VALUE\n newline separated".into(),
+            params: vec![Parameter::new_ref("foo", Some("bar"))]
+        }
+    );
+
     assert_parser!(
         property,
         "KEY3;foo=bar:VALUE\\n newline separated\n",
         Property {
             name: "KEY3".into(),
-            val: "VALUE\\n newline separated".into(),
+            val: "VALUE\n newline separated".into(),
             params: vec![Parameter::new_ref("foo", Some("bar"))]
         }
     );
@@ -192,7 +202,6 @@ fn test_property_with_dash() {
 
 #[test]
 fn parse_properties_from_rfc() {
-    // TODO: newlines followed by spaces must be ignored
     assert_parser!(
         property,
         "home.tel;type=fax,voice,msg:+49 3581 123456\n",
@@ -202,7 +211,7 @@ fn parse_properties_from_rfc() {
             params: vec![Parameter::new_ref("type", Some("fax,voice,msg"),)]
         }
     );
-    // TODO: newlines followed by spaces must be ignored
+
     assert_parser!(
         property,
         "email;internet:[email protected]\n",
@@ -221,7 +230,7 @@ fn parse_property_with_breaks() {
 
     let expectation = Property {
         name: "DESCRIPTION".into(),
-        val: "Hey, I'm gonna have a party\\n BYOB: Bring your own beer.\\n Hendrik\\n".into(),
+        val: "Hey, I'm gonna have a party\n BYOB: Bring your own beer.\n Hendrik\n".into(),
         params: vec![],
     };
 
@@ -309,8 +318,8 @@ pub fn property<'a, E: ParseError<&'a str> + ContextError<&'a str>>(
                             // this is for single line prop parsing, just so I can leave off the '\n'
                             take_while(|_| true),
                         ))
-                        .map(ParseString::from),
-                    ), // val TODO: replace this with something simpler!
+                        .map(|x| ParseString::from(x).unescape_text()),
+                    ),
                 ),
                 context(
                     "no-value property",

src/properties.rs

@@ -53,7 +53,7 @@ impl Property {
     pub fn new(key: &str, val: &str) -> Self {
         Property {
             key: key.to_owned(),
-            val: val.replace('\n', "\\n"),
+            val: val.to_owned(),
             params: HashMap::new(),
         }
     }
@@ -62,7 +62,7 @@ impl Property {
     pub fn new_pre_alloc(key: String, val: String) -> Self {
         Property {
             key,
-            val: val.replace('\n', "\\n"),
+            val,
             params: HashMap::new(),
         }
     }
@@ -140,16 +140,38 @@ impl Property {
         }
     }
 
+    /// <https://datatracker.ietf.org/doc/html/rfc5545#section-3.3.11>
+    fn escape_text(input: &str) -> String {
+        input
+            .replace('\\', r#"\\"#)
+            .replace(',', r#"\,"#)
+            .replace(';', r#"\;"#)
+            .replace(':', r#"\:"#)
+            .replace('\n', r#"\N"#)
+    }
+
+    fn quote_if_contains_colon(input: &str) -> String {
+        if input.contains([':', ';']) {
+            let mut quoted = String::with_capacity(input.len() + 2);
+            quoted.push('"');
+            quoted.push_str(input);
+            quoted.push('"');
+            quoted
+        } else {
+            input.to_string()
+        }
+    }
+
     /// Writes this Property to `out`
     pub(crate) fn fmt_write<W: Write>(&self, out: &mut W) -> Result<(), fmt::Error> {
         // A nice starting capacity for the majority of content lines
         let mut line = String::with_capacity(150);
 
         write!(line, "{}", self.key)?;
-        for Parameter { key, val: value } in self.params.values() {
-            write!(line, ";{}={}", key, value)?;
+        for Parameter { key, val } in self.params.values() {
+            write!(line, ";{}={}", key, Self::quote_if_contains_colon(val))?;
         }
-        write!(line, ":{}", self.val)?;
+        write!(line, ":{}", Self::escape_text(&self.val))?;
         write_crlf!(out, "{}", fold_line(&line))?;
         Ok(())
     }