try to work around mailparser not decoding rfc2047 displaynames

this pulls in changes in our fork of rust-email  to also correctly
generate rfc2047 encoding

Cargo.lock

@@ -656,6 +656,7 @@ dependencies = [
  "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "debug_stub_derive 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "deltachat_derive 0.1.0",
+ "email 0.0.21 (git+https://github.com/deltachat/rust-email)",
  "encoded-words 0.1.0 (git+https://github.com/async-email/encoded-words)",
  "escaper 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -827,10 +828,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "email"
 version = "0.0.21"
-source = "git+https://github.com/deltachat/rust-email#265a54a8c31355c506610c032c81112dc0953afb"
+source = "git+https://github.com/deltachat/rust-email#b71c13d7d9a599ebc811a8e2ca350e2793fe58d3"
 dependencies = [
  "base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "encoded-words 0.1.0 (git+https://github.com/async-email/encoded-words)",
  "encoding 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -18,6 +18,7 @@ reqwest = { version = "0.9.15", default-features = false, features = ["rustls-tl
 num-derive = "0.2.5"
 num-traits = "0.2.6"
 async-smtp = { git = "https://github.com/async-email/async-smtp" }
+email = { git = "https://github.com/deltachat/rust-email" }
 lettre_email = { git = "https://github.com/deltachat/lettre", branch = "feat/mail" }
 async-imap = { git = "https://github.com/async-email/async-imap", branch="master" }
 async-tls = "0.6"

src/dc_receive_imf.rs

@@ -1583,6 +1583,10 @@ fn dc_add_or_lookup_contacts_by_address_list(
     origin: Origin,
     to_ids: &mut ContactIds,
 ) -> Result<()> {
+    // XXX we use manual decoding
+    // https://github.com/staktrace/mailparse/issues/50
+    use email::rfc2047::decode_rfc2047;
+
     let addrs = match mailparse::addrparse(addr_list_raw) {
         Ok(addrs) => addrs,
         Err(err) => {
@@ -1597,18 +1601,22 @@ fn dc_add_or_lookup_contacts_by_address_list(
     for addr in addrs.iter() {
         match addr {
             mailparse::MailAddr::Single(info) => {
+                // mailparse does not give us decoded vals
+                let display_name = decode_rfc2047(&info.display_name.clone().unwrap_or_default());
                 to_ids.insert(add_or_lookup_contact_by_addr(
                     context,
-                    &info.display_name,
+                    &display_name,
                     &info.addr,
                     origin,
                 )?);
             }
             mailparse::MailAddr::Group(infos) => {
                 for info in &infos.addrs {
+                    let display_name =
+                        decode_rfc2047(&info.display_name.clone().unwrap_or_default());
                     to_ids.insert(add_or_lookup_contact_by_addr(
                         context,
-                        &info.display_name,
+                        &display_name,
                         &info.addr,
                         origin,
                     )?);

src/mimefactory.rs

@@ -1051,3 +1051,40 @@ pub fn needs_encoding(to_check: impl AsRef<str>) -> bool {
         !c.is_ascii_alphanumeric() && c != '-' && c != '_' && c != '.' && c != '~' && c != '%'
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use email::rfc2047::decode_rfc2047;
+    use mailparse::{addrparse, MailAddr};
+
+    #[test]
+    fn test_render_email_address() {
+        let display_name = "ä space";
+        let addr = "x@y.org";
+
+        assert!(!display_name.is_ascii());
+
+        let s = format!(
+            "{}",
+            Address::new_mailbox_with_name(display_name.to_string(), addr.to_string())
+        );
+
+        println!("{}", s);
+        assert!(s.is_ascii());
+
+        assert_eq!(s, "=?utf-8?q?=C3=A4_space?= <x@y.org>");
+
+        match &addrparse(&s).unwrap()[0] {
+            MailAddr::Single(info) => {
+                // XXX addrparse should not return rfc2047 encoding
+                // but the decoded string, see
+                // https://github.com/staktrace/mailparse/issues/50
+                let s = decode_rfc2047(&info.display_name.clone().unwrap());
+                assert_eq!(s, Some(display_name.to_string()));
+                assert_eq!(info.addr, addr.to_string());
+            }
+            _ => panic!(),
+        }
+    }
+}