Fix ANSI colors in Windows CMD and PowerShell

Cargo.toml

@@ -18,3 +18,7 @@ travis-ci = { repository = "colin-kiegel/rust-pretty-assertions" }
 [dependencies]
 difference = "2.0.0"
 ansi_term = "0.11"
+
+[target.'cfg(windows)'.dependencies]
+output_vt100 = "0.1"
+ctor = "0.1.7"

README.md

@@ -67,6 +67,8 @@ extern crate pretty_assertions;
   you include.
 * `assert_ne` is also switched to multi-line presentation, but does _not_ show
   a diff.
+* Under Windows, the terminal state is modified to properly handle VT100 
+  escape sequences, which may break display for certain use cases.
 
 ## License
 

src/lib.rs

@@ -2,7 +2,7 @@
 //!
 //! When writing tests in Rust, you'll probably use `assert_eq!(a, b)` _a lot_.
 //!
-//! If such a test fails, it will present all the details of `a` and `b`. 
+//! If such a test fails, it will present all the details of `a` and `b`.
 //! But you have to spot the differences yourself, which is not always straightforward,
 //! like here:
 //!
@@ -67,6 +67,12 @@
 
 extern crate difference;
 extern crate ansi_term;
+
+#[cfg(windows)]
+extern crate output_vt100;
+#[cfg(windows)]
+extern crate ctor;
+
 mod format_changeset;
 
 use std::fmt::{self, Debug, Display};
@@ -75,6 +81,14 @@ use difference::Changeset;
 use format_changeset::format_changeset;
 pub use ansi_term::Style;
 
+#[cfg(windows)]
+use ctor::*;
+#[cfg(windows)]
+#[ctor]
+fn init() {
+    output_vt100::init();
+}
+
 #[doc(hidden)]
 pub struct Comparison(Changeset);