fix Eq+Hash for Constant

src/consts.rs

@@ -85,7 +85,7 @@ fn eq(&self, other: &Constant) -> bool {
             (&Constant::Str(ref ls, ref lsty), &Constant::Str(ref rs, ref rsty)) => ls == rs && lsty == rsty,
             (&Constant::Binary(ref l), &Constant::Binary(ref r)) => l == r,
             (&Constant::Char(l), &Constant::Char(r)) => l == r,
-            (&Constant::Int(l), &Constant::Int(r)) => l == r,
+            (&Constant::Int(l), &Constant::Int(r)) => l.is_negative() == r.is_negative() && l.to_u64_unchecked() == r.to_u64_unchecked(),
             (&Constant::Float(ref ls, _), &Constant::Float(ref rs, _)) => {
                 // we want `Fw32 == FwAny` and `FwAny == Fw64`, by transitivity we must have
                 // `Fw32 == Fw64` so don’t compare them
@@ -119,7 +119,8 @@ fn hash<H>(&self, state: &mut H)
                 c.hash(state);
             }
             Constant::Int(i) => {
-                i.hash(state);
+                i.to_u64_unchecked().hash(state);
+                i.is_negative().hash(state);
             }
             Constant::Float(ref f, _) => {
                 // don’t use the width here because of PartialEq implementation

src/identity_op.rs

@@ -55,11 +55,11 @@ fn check_expr(&mut self, cx: &LateContext, e: &Expr) {
 
 
 fn check(cx: &LateContext, e: &Expr, m: i8, span: Span, arg: Span) {
-    if let Some(Constant::Int(v)) = constant_simple(e) {
+    if let Some(v @ Constant::Int(_)) = constant_simple(e) {
         if match m {
-            0 => v == ConstInt::Infer(0),
-            -1 => v == ConstInt::InferSigned(-1),
-            1 => v == ConstInt::Infer(1),
+            0 => v == Constant::Int(ConstInt::Infer(0)),
+            -1 => v == Constant::Int(ConstInt::InferSigned(-1)),
+            1 => v == Constant::Int(ConstInt::Infer(1)),
             _ => unreachable!(),
         } {
             span_lint(cx,

tests/consts.rs

@@ -86,4 +86,8 @@ fn test_ops() {
     assert_eq!(half_any, half32);
     assert_eq!(half_any, half64);
     assert_eq!(half32, half64); // for transitivity
+
+    assert_eq!(Constant::Int(ConstInt::Infer(0)), Constant::Int(ConstInt::U8(0)));
+    assert_eq!(Constant::Int(ConstInt::Infer(0)), Constant::Int(ConstInt::I8(0)));
+    assert_eq!(Constant::Int(ConstInt::InferSigned(-1)), Constant::Int(ConstInt::I8(-1)));
 }