From fbb1c280bf5f3d4fc68f323860ade8fa48d96979 Mon Sep 17 00:00:00 2001
From: Daiki Mizukami <mizukami1113@gmail.com>
Date: Tue, 24 Apr 2018 01:45:44 +0900
Subject: [PATCH 1/2] core: Fix overflow in `int::mod_euc` when `self < 0 &&
 rhs == MIN`

---
 src/libcore/num/mod.rs              | 6 +++++-
 src/libcore/tests/lib.rs            | 1 +
 src/libcore/tests/num/int_macros.rs | 5 +++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index aa4d4bc638b1d..4893e05badcb5 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -1765,7 +1765,11 @@ assert_eq!((-a).mod_euc(-b), 1);
             pub fn mod_euc(self, rhs: Self) -> Self {
                 let r = self % rhs;
                 if r < 0 {
-                    r + rhs.abs()
+                    if rhs.is_negative() {
+                        r - rhs
+                    } else {
+                        r + rhs
+                    }
                 } else {
                     r
                 }
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 7d3852d2f2a98..ccf647c358d67 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -15,6 +15,7 @@
 #![feature(core_private_diy_float)]
 #![feature(dec2flt)]
 #![feature(decode_utf8)]
+#![feature(euclidean_division)]
 #![feature(exact_size_is_empty)]
 #![feature(fixed_size_array)]
 #![feature(float_internals)]
diff --git a/src/libcore/tests/num/int_macros.rs b/src/libcore/tests/num/int_macros.rs
index 8d791283ab87e..71d2e7945389b 100644
--- a/src/libcore/tests/num/int_macros.rs
+++ b/src/libcore/tests/num/int_macros.rs
@@ -30,6 +30,11 @@ mod tests {
         num::test_num(10 as $T, 2 as $T);
     }
 
+    #[test]
+    fn test_mod_euc() {
+        assert!((-1 as $T).mod_euc(MIN) == MAX);
+    }
+
     #[test]
     pub fn test_abs() {
         assert!((1 as $T).abs() == 1 as $T);

From 104c64dc360f297fbdd4a467dac1c5006d76dece Mon Sep 17 00:00:00 2001
From: Daiki Mizukami <mizukami1113@gmail.com>
Date: Tue, 24 Apr 2018 03:32:40 +0900
Subject: [PATCH 2/2] core: Minor cleanup

---
 src/libcore/num/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 4893e05badcb5..a062fbda5bad0 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -1765,7 +1765,7 @@ assert_eq!((-a).mod_euc(-b), 1);
             pub fn mod_euc(self, rhs: Self) -> Self {
                 let r = self % rhs;
                 if r < 0 {
-                    if rhs.is_negative() {
+                    if rhs < 0 {
                         r - rhs
                     } else {
                         r + rhs