use std::error::Error;
use std::{fmt, io};

/// This type represents the possible errors that can occur while
/// sending DogstatsD metrics.
#[derive(Debug)]
pub enum DogstatsdError {
    /// Chained IO errors.
    IoError(io::Error),
}

use self::DogstatsdError::*;

impl fmt::Display for DogstatsdError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            IoError(ref error) => write!(f, "{}", error),
        }
    }
}

impl Error for DogstatsdError {
    fn description(&self) -> &str {
        match *self {
            IoError(ref error) => error.description(),
        }
    }
}

impl From<io::Error> for DogstatsdError {
    fn from(e: io::Error) -> Self {
        IoError(e)
    }
}

#[cfg(test)]
mod tests {
    use super::DogstatsdError;
    use std::io;

    #[test]
    fn test_error_display() {
        let err = DogstatsdError::from(io::Error::new(io::ErrorKind::Other, "oh no!"));
        assert_eq!(format!("{}", err), "oh no!".to_owned());
    }
}

use std::error::Error;
use std::{fmt, io};

/// This type represents the possible errors that can occur while
/// sending DogstatsD metrics.
#[derive(Debug)]
pub enum DogstatsdError {
    /// Chained IO errors.
    IoError(io::Error),
}

use self::DogstatsdError::*;

impl fmt::Display for DogstatsdError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self)
    }
}

impl Error for DogstatsdError {
    fn description(&self) -> &str {
        match *self {
            IoError(ref error) => error.description(),
        }
    }
}

impl From<io::Error> for DogstatsdError {
    fn from(e: io::Error) -> Self {
        IoError(e)
    }
}

--- 
+++ 
@@ -13,7 +13,9 @@
 
 impl fmt::Display for DogstatsdError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self)
+        match *self {
+            IoError(ref error) => write!(f, "{}", error),
+        }
     }
 }
 
@@ -30,3 +32,15 @@
         IoError(e)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::DogstatsdError;
+    use std::io;
+
+    #[test]
+    fn test_error_display() {
+        let err = DogstatsdError::from(io::Error::new(io::ErrorKind::Other, "oh no!"));
+        assert_eq!(format!("{}", err), "oh no!".to_owned());
+    }
+}
Fix Display impl for DogstatsdError.

The previous implementation was accidentally recursing, which would
cause a stack-overflow whenever an error was displayed. This change
switches to using the impl of Display for the `IoError`, and adds a
test.
