From 90bdb7e96dd4d09abe850d4b083052cb4e980455 Mon Sep 17 00:00:00 2001
From: Alan Du <alanhdu@gmail.com>
Date: Tue, 30 May 2017 23:49:26 +0100
Subject: [PATCH] Encode control characters with hex not decimal

Fix https://github.com/alexcrichton/toml-rs/issues/178
---
 src/ser.rs                      | 2 +-
 tests/valid/unicode-escape.json | 1 +
 tests/valid/unicode-escape.toml | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/ser.rs b/src/ser.rs
index 9af304f..de5d41c 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -290,7 +290,7 @@ impl<'a> Serializer<'a> {
                 '\u{22}' => drop(write!(self.dst, "\\\"")),
                 '\u{5c}' => drop(write!(self.dst, "\\\\")),
                 c if c < '\u{1f}' => {
-                    drop(write!(self.dst, "\\u{:04}", ch as u32))
+                    drop(write!(self.dst, "\\u{:04X}", ch as u32))
                 }
                 ch => drop(write!(self.dst, "{}", ch)),
             }
diff --git a/tests/valid/unicode-escape.json b/tests/valid/unicode-escape.json
index 8c09dc0..32948c6 100644
--- a/tests/valid/unicode-escape.json
+++ b/tests/valid/unicode-escape.json
@@ -1,4 +1,5 @@
 {
+    "answer1": {"type": "string", "value": "\u000B"},
     "answer4": {"type": "string", "value": "\u03B4α"},
     "answer8": {"type": "string", "value": "\u03B4β"}
 }
diff --git a/tests/valid/unicode-escape.toml b/tests/valid/unicode-escape.toml
index 20198f4..c0d5a25 100644
--- a/tests/valid/unicode-escape.toml
+++ b/tests/valid/unicode-escape.toml
@@ -1,2 +1,3 @@
+answer1 = "\u000B"
 answer4 = "\u03B4α"
 answer8 = "\U000003B4β"