use encoded-words crate, which friedel ported from python

Cargo.lock

@@ -620,6 +620,7 @@ 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",
+ "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)",
  "failure_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -639,7 +640,6 @@ dependencies = [
  "pretty_env_logger 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "quick-xml 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "quoted_printable 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "r2d2 0.8.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "r2d2_sqlite 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -797,6 +797,20 @@ dependencies = [
  "version_check 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "encoded-words"
+version = "0.1.0"
+source = "git+https://github.com/async-email/encoded-words#019e833f0c9ea7d4b0b693aab44e66d78d18f1d0"
+dependencies = [
+ "base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "charset 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "encoding_rs 0.8.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hex 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thiserror 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "encoding"
 version = "0.2.33"
@@ -2761,6 +2775,24 @@ dependencies = [
  "wincolor 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "thiserror-impl 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "thread-local-object"
 version = "0.1.0"
@@ -3429,6 +3461,7 @@ dependencies = [
 "checksum ed25519-dalek 1.0.0-pre.2 (registry+https://github.com/rust-lang/crates.io-index)" = "845aaacc16f01178f33349e7c992ecd0cee095aa5e577f0f4dee35971bd36455"
 "checksum either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
 "checksum email 0.0.21 (git+https://github.com/deltachat/rust-email)" = "<none>"
+"checksum encoded-words 0.1.0 (git+https://github.com/async-email/encoded-words)" = "<none>"
 "checksum encoding 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "6b0d943856b990d12d3b55b359144ff341533e516d94098b1d3fc1ac666d36ec"
 "checksum encoding-index-japanese 1.20141219.5 (registry+https://github.com/rust-lang/crates.io-index)" = "04e8b2ff42e9a05335dbf8b5c6f7567e5591d0d916ccef4e0b1710d32a0d0c91"
 "checksum encoding-index-korean 1.20141219.5 (registry+https://github.com/rust-lang/crates.io-index)" = "4dc33fb8e6bcba213fe2f14275f0963fd16f0a02c878e3095ecfdf5bee529d81"
@@ -3645,6 +3678,8 @@ dependencies = [
 "checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 "checksum termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "adc4587ead41bf016f11af03e55a624c06568b5a19db4e90fde573d805074f83"
 "checksum termcolor 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "96d6098003bde162e4277c70665bd87c326f5a0c3f3fbfb285787fa482d54e6e"
+"checksum thiserror 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "6f357d1814b33bc2dc221243f8424104bfe72dbe911d5b71b3816a2dff1c977e"
+"checksum thiserror-impl 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)" = "eb2e25d25307eb8436894f727aba8f65d07adf02e5b35a13cebed48bd282bfef"
 "checksum thread-local-object 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7da3caa820d0308c84c8654f6cafd81cc3195d45433311cbe22fcf44fc8be071"
 "checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"

Cargo.toml

@@ -54,7 +54,7 @@ rustls = "0.16.0"
 webpki-roots = "0.18.0"
 webpki = "0.21.0"
 mailparse = "0.10.1"
-quoted_printable = "0.4.1"
+encoded-words = { git = "https://github.com/async-email/encoded-words", branch="master" }
 
 [dev-dependencies]
 tempfile = "3.0"

src/lib.rs

@@ -1,5 +1,5 @@
 #![deny(clippy::correctness, missing_debug_implementations, clippy::all)]
-// for now we hide warnings to not clutter/hide errors during "cargo check"
+// for now we hide warnings to not clutter/hide errors during "cargo clippy"
 #![allow(
     clippy::type_complexity,
     clippy::cognitive_complexity,

src/mimefactory.rs

@@ -382,7 +382,7 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
         let mut unprotected_headers: Vec<Header> = Vec::new();
 
         let from = Address::new_mailbox_with_name(
-            quoted_printable::encode_to_str(&self.from_displayname),
+            encode_words(&self.from_displayname),
             self.from_addr.clone(),
         );
 
@@ -394,7 +394,7 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
                 to.push(Address::new_mailbox(addr.clone()));
             } else {
                 to.push(Address::new_mailbox_with_name(
-                    quoted_printable::encode_to_str(name),
+                    encode_words(name),
                     addr.clone(),
                 ));
             }
@@ -450,7 +450,7 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
         let e2ee_guranteed = self.is_e2ee_guranteed();
         let mut encrypt_helper = EncryptHelper::new(self.context)?;
 
-        let subject = quoted_printable::encode_to_str(&subject_str);
+        let subject = encode_words(&subject_str);
 
         let mut message = match self.loaded {
             Loaded::Message => {
@@ -610,7 +610,7 @@ impl<'a, 'b> MimeFactory<'a, 'b> {
         if chat.typ == Chattype::Group || chat.typ == Chattype::VerifiedGroup {
             protected_headers.push(Header::new("Chat-Group-ID".into(), chat.grpid.clone()));
 
-            let encoded = quoted_printable::encode_to_str(&chat.name);
+            let encoded = encode_words(&chat.name);
             protected_headers.push(Header::new("Chat-Group-Name".into(), encoded));
 
             match command {
@@ -988,7 +988,7 @@ fn build_body_file(
     let cd_value = if needs_encoding(&filename_to_send) {
         format!(
             "attachment; filename*=\"{}\"",
-            quoted_printable::encode_to_str(&filename_to_send)
+            encode_words(&filename_to_send)
         )
     } else {
         format!("attachment; filename=\"{}\"", &filename_to_send)
@@ -1030,6 +1030,10 @@ fn is_file_size_okay(context: &Context, msg: &Message) -> bool {
  * Encode/decode header words, RFC 2047
  ******************************************************************************/
 
+fn encode_words(word: &str) -> String {
+    encoded_words::encode(word, None, encoded_words::EncodingFlag::Shortest, None)
+}
+
 pub fn needs_encoding(to_check: impl AsRef<str>) -> bool {
     let to_check = to_check.as_ref();
 

src/mimeparser.rs

@@ -579,23 +579,14 @@ impl<'a> MimeParser<'a> {
                 //    `Content-Disposition: ... filename*=...`
                 // or `Content-Disposition: ... filename*0*=... filename*1*=... filename*2*=...`
                 // or `Content-Disposition: ... filename=...`
-                use quoted_printable::ParseMode::Robust;
 
                 let ct = mail.get_content_disposition()?;
                 let mut desired_filename = ct
                     .params
                     .iter()
                     .filter(|(key, _value)| key.starts_with("filename"))
-                    .fold(String::new(), |mut acc, (key, value)| {
+                    .fold(String::new(), |mut acc, (_key, value)| {
-                        if key.starts_with("filename*") {
-                            quoted_printable::decode(&value, Robust)
-                                .map(|ref res| {
-                                    acc += &String::from_utf8_lossy(res);
-                                })
-                                .ok();
-                        } else {
                         acc += value;
-                        };
                         acc
                     });