From 8eaac0843eb206c37b52db9d96094503487cd076 Mon Sep 17 00:00:00 2001
From: topecongiro <seuchida@gmail.com>
Date: Fri, 17 Mar 2017 09:03:52 +0900
Subject: [PATCH] Parse 0e+10 as a valid floating-point literal

Fixes issue #40408.
---
 src/libsyntax/parse/lexer/mod.rs |  2 +-
 src/test/run-pass/issue-40408.rs | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 src/test/run-pass/issue-40408.rs

diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index de8a87e3a2b32..d48cf6911ed37 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -725,7 +725,7 @@ impl<'a> StringReader<'a> {
                     base = 16;
                     num_digits = self.scan_digits(16, 16);
                 }
-                '0'...'9' | '_' | '.' => {
+                '0'...'9' | '_' | '.' | 'e' | 'E' => {
                     num_digits = self.scan_digits(10, 10) + 1;
                 }
                 _ => {
diff --git a/src/test/run-pass/issue-40408.rs b/src/test/run-pass/issue-40408.rs
new file mode 100644
index 0000000000000..a73dc1966b4be
--- /dev/null
+++ b/src/test/run-pass/issue-40408.rs
@@ -0,0 +1,16 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    println!("{}", 0E+10);
+    println!("{}", 0e+10);
+    println!("{}", 00e+10);
+    println!("{}", 00E+10);
+}