melib/email: add case-insensitive Header struct

- HeaderName is either 32 or less inlined bytes or heap-allocated vec for more than that.
- Equality and hashing is case-insensitive
- A HeaderMap is a hashmap from HeaderName to Strings that can be
indexed with &str, case insensitive. Insertion order is also preserved

2 files changed, 3 insertions, 19 deletions

diff --git a/tests/generated.mail b/tests/generated.mail
index 267c23a0..20f23ff0 100644
--- a/tests/generated.mail
+++ b/tests/generated.mail
@@ -1,8 +1,8 @@
+Subject: 
 From: 
 To: 
 Cc: 
 Bcc: 
-Subject: 
 MIME-Version: 1.0
 Content-Type: multipart/mixed; charset="utf-8"; boundary="bzz_bzz__bzz__"
 
diff --git a/tests/generating_email.rs b/tests/generating_email.rs
index c0acd498..04b94a9d 100644
--- a/tests/generating_email.rs
+++ b/tests/generating_email.rs
@@ -15,24 +15,8 @@ fn build_draft() {
             _ => {}
         }
     }
-    if new_draft.headers().contains_key("User-Agent") {
-        new_draft.headers_mut().remove("User-Agent");
-        let pos = new_draft
-            .header_order
-            .iter()
-            .position(|k| k == "User-Agent")
-            .unwrap();
-        new_draft.header_order.remove(pos);
-    }
-    {
-        new_draft.headers_mut().remove("Date");
-        let pos = new_draft
-            .header_order
-            .iter()
-            .position(|k| k == "Date")
-            .unwrap();
-        new_draft.header_order.remove(pos);
-    }
+    new_draft.headers_mut().remove("User-Agent");
+    new_draft.headers_mut().remove("Date");
 
     new_draft.attachments_mut().push(attachment);
     new_draft.set_body("hello world.".to_string());