This fixes #23 don't put 0 size read result into buffer. This will prevent it from filling up memory when reading responses

src/client.rs

@@ -443,8 +443,10 @@ impl<T: Read+Write> Client<T> {
 		let mut line_buffer: Vec<u8> = Vec::new();
 		while line_buffer.len() < 2 || (line_buffer[line_buffer.len()-1] != LF && line_buffer[line_buffer.len()-2] != CR) {
 			let byte_buffer: &mut [u8] = &mut [0];
-			try!(self.stream.read(byte_buffer));
+			let n = try!(self.stream.read(byte_buffer));
-			line_buffer.push(byte_buffer[0]);
+			if n > 0 {
+				line_buffer.push(byte_buffer[0]);
+			}
 		}
 
 		if self.debug {
@@ -490,6 +492,7 @@ mod tests {
 		assert!(expected_response == actual_response, "expected response doesn't equal actual");
 	}
 
+
 	#[test]
 	fn read_greeting() {
 		let greeting = "* OK Dovecot ready.\r\n";
@@ -498,6 +501,16 @@ mod tests {
 		client.read_greeting().unwrap();
 	}
 
+	#[test]
+	fn readline_delay_read() {
+		let greeting = "* OK Dovecot ready.\r\n";
+		let expected_response: String = greeting.to_string();
+		let mock_stream = MockStream::new_read_delay(greeting.as_bytes().to_vec());
+		let mut client = Client::new(mock_stream);
+		let actual_response = String::from_utf8(client.readline().unwrap()).unwrap();
+		assert_eq!(expected_response, actual_response);
+	}
+
 	#[test]
 	#[should_panic]
 	fn readline_err() {

src/mock_stream.rs

@@ -5,7 +5,8 @@ pub struct MockStream {
     read_buf: Vec<u8>,
     read_pos: usize,
     pub written_buf: Vec<u8>,
-    err_on_read: bool
+    err_on_read: bool,
+    read_delay: usize
 }
 
 impl MockStream {
@@ -14,7 +15,8 @@ impl MockStream {
             read_buf: read_buf,
             read_pos: 0,
             written_buf: Vec::new(),
-            err_on_read: false
+            err_on_read: false,
+            read_delay: 0
         }
     }
 
@@ -23,13 +25,28 @@ impl MockStream {
             read_buf: Vec::new(),
             read_pos: 0,
             written_buf: Vec::new(),
-            err_on_read: true
+            err_on_read: true,
+            read_delay: 0
+        }
+    }
+
+    pub fn new_read_delay(read_buf: Vec<u8>) -> MockStream {
+        MockStream{
+            read_buf: read_buf,
+            read_pos: 0,
+            written_buf: Vec::new(),
+            err_on_read: false,
+            read_delay: 1,
         }
     }
 }
 
 impl Read for MockStream {
     fn read(&mut self, buf: &mut[u8]) -> Result<usize> {
+        if self.read_delay > 0 {
+            self.read_delay -= 1;
+            return Ok(0)
+        }
         if self.err_on_read {
             return Err(Error::new(ErrorKind::Other, "MockStream Error"))
         }