avoid panic for headers

src/agent.rs

@@ -119,7 +119,7 @@ impl Agent {
     {
         add_header(
             &mut self.headers,
-            Header::new(&header.into(), &value.into()).expect("Failed to parse header"),
+            Header::new(&header.into(), &value.into()),
         );
         self
     }

src/header.rs

@@ -1,4 +1,4 @@
-use ascii::AsciiString;
+use ascii::{AsAsciiStr, AsciiString};
 use error::Error;
 use std::str::FromStr;
 
@@ -16,11 +16,11 @@ impl ::std::fmt::Debug for Header {
 }
 
 impl Header {
-    pub fn new(name: &str, value: &str) -> Result<Self, Error> {
-        let line =
-            AsciiString::from_str(&format!("{}: {}", name, value)).map_err(|_| Error::BadHeader)?;
+    pub fn new(name: &str, value: &str) -> Self {
+        let s = format!("{}: {}", name, value);
+        let line = unsafe { s.as_ascii_str_unchecked().to_owned() };
         let index = name.len();
-        Ok(Header { line, index })
+        Header { line, index }
     }
 
     /// The header name.

src/request.rs

@@ -190,10 +190,7 @@ impl Request {
         K: Into<String>,
         V: Into<String>,
     {
-        add_header(
-            &mut self.headers,
-            Header::new(&header.into(), &value.into()).expect("Failed to parse header"),
-        );
+        add_header(&mut self.headers, Header::new(&header.into(), &value.into()));
         self
     }
 

src/unit.rs

@@ -58,7 +58,7 @@ impl Unit {
             // also don't write this if the user has set it themselves
             if !is_chunked && !req.has("content-length") {
                 if let Some(size) = body.size {
-                    extra.push(Header::new("Content-Length", &format!("{}", size)).unwrap());
+                    extra.push(Header::new("Content-Length", &format!("{}", size)));
                 }
             }
 
@@ -66,7 +66,7 @@ impl Unit {
             let password = url.password().unwrap_or("");
             if (username != "" || password != "") && !req.has("authorization") {
                 let encoded = base64::encode(&format!("{}:{}", username, password));
-                extra.push(Header::new("Authorization", &format!("Basic {}", encoded)).unwrap());
+                extra.push(Header::new("Authorization", &format!("Basic {}", encoded)));
             }
 
             extra
@@ -204,10 +204,8 @@ fn match_cookies<'a>(jar: &'a CookieJar, domain: &str, path: &str, is_secure: bo
             let name = c.name().to_string();
             let value = c.value().to_string();
             let nameval = Cookie::new(name, value).encoded().to_string();
-            Header::new("Cookie", &nameval).ok()
+            Header::new("Cookie", &nameval)
         })
-        .filter(|o| o.is_some())
-        .map(|o| o.unwrap())
         .collect()
 }