Auto merge of #5046 - JohnTitor:order-nonminimal-bool, r=flip1995

Keep the ordering in `nonminimal_bool` lint

I believe it shouldn't cause any regression but feel free to let me know if you have a doubtful example.
Also, splits up `booleans` ui test.

Fixes #5045

changelog: none

Author: bors

clippy_lints/src/booleans.rs

@@ -207,7 +207,7 @@ impl<'a, 'tcx, 'v> SuggestContext<'a, 'tcx, 'v> {
                 }
             },
             Or(v) => {
-                for (index, inner) in v.iter().enumerate() {
+                for (index, inner) in v.iter().rev().enumerate() {
                     if index > 0 {
                         self.output.push_str(" || ");
                     }

tests/ui/booleans.stderr

@@ -0,0 +1,26 @@
+#![allow(unused, clippy::many_single_char_names)]
+#![warn(clippy::logic_bug)]
+
+fn main() {
+    let a: bool = unimplemented!();
+    let b: bool = unimplemented!();
+    let c: bool = unimplemented!();
+    let d: bool = unimplemented!();
+    let e: bool = unimplemented!();
+    let _ = a && b || a;
+    let _ = !(a && b);
+    let _ = false && a;
+    // don't lint on cfgs
+    let _ = cfg!(you_shall_not_not_pass) && a;
+    let _ = a || !b || !c || !d || !e;
+    let _ = !(a && b || c);
+}
+
+fn equality_stuff() {
+    let a: i32 = unimplemented!();
+    let b: i32 = unimplemented!();
+    let _ = a == b && a != b;
+    let _ = a < b && a >= b;
+    let _ = a > b && a <= b;
+    let _ = a > b && a == b;
+}

tests/ui/logic_bug.rs

@@ -0,0 +1,63 @@
+error: this boolean expression contains a logic bug
+  --> $DIR/logic_bug.rs:10:13
+   |
+LL |     let _ = a && b || a;
+   |             ^^^^^^^^^^^ help: it would look like the following: `a`
+   |
+   = note: `-D clippy::logic-bug` implied by `-D warnings`
+help: this expression can be optimized out by applying boolean operations to the outer expression
+  --> $DIR/logic_bug.rs:10:18
+   |
+LL |     let _ = a && b || a;
+   |                  ^
+
+error: this boolean expression contains a logic bug
+  --> $DIR/logic_bug.rs:12:13
+   |
+LL |     let _ = false && a;
+   |             ^^^^^^^^^^ help: it would look like the following: `false`
+   |
+help: this expression can be optimized out by applying boolean operations to the outer expression
+  --> $DIR/logic_bug.rs:12:22
+   |
+LL |     let _ = false && a;
+   |                      ^
+
+error: this boolean expression contains a logic bug
+  --> $DIR/logic_bug.rs:22:13
+   |
+LL |     let _ = a == b && a != b;
+   |             ^^^^^^^^^^^^^^^^ help: it would look like the following: `false`
+   |
+help: this expression can be optimized out by applying boolean operations to the outer expression
+  --> $DIR/logic_bug.rs:22:13
+   |
+LL |     let _ = a == b && a != b;
+   |             ^^^^^^
+
+error: this boolean expression contains a logic bug
+  --> $DIR/logic_bug.rs:23:13
+   |
+LL |     let _ = a < b && a >= b;
+   |             ^^^^^^^^^^^^^^^ help: it would look like the following: `false`
+   |
+help: this expression can be optimized out by applying boolean operations to the outer expression
+  --> $DIR/logic_bug.rs:23:13
+   |
+LL |     let _ = a < b && a >= b;
+   |             ^^^^^
+
+error: this boolean expression contains a logic bug
+  --> $DIR/logic_bug.rs:24:13
+   |
+LL |     let _ = a > b && a <= b;
+   |             ^^^^^^^^^^^^^^^ help: it would look like the following: `false`
+   |
+help: this expression can be optimized out by applying boolean operations to the outer expression
+  --> $DIR/logic_bug.rs:24:13
+   |
+LL |     let _ = a > b && a <= b;
+   |             ^^^^^
+
+error: aborting due to 5 previous errors
+

tests/ui/logic_bug.stderr

@@ -0,0 +1,52 @@
+#![allow(unused, clippy::many_single_char_names)]
+#![warn(clippy::nonminimal_bool)]
+
+fn main() {
+    let a: bool = unimplemented!();
+    let b: bool = unimplemented!();
+    let c: bool = unimplemented!();
+    let d: bool = unimplemented!();
+    let e: bool = unimplemented!();
+    let _ = !true;
+    let _ = !false;
+    let _ = !!a;
+    let _ = false || a;
+    // don't lint on cfgs
+    let _ = cfg!(you_shall_not_not_pass) && a;
+    let _ = a || !b || !c || !d || !e;
+    let _ = !(!a && b);
+    let _ = !(!a || b);
+    let _ = !a && !(b && c);
+}
+
+fn equality_stuff() {
+    let a: i32 = unimplemented!();
+    let b: i32 = unimplemented!();
+    let c: i32 = unimplemented!();
+    let d: i32 = unimplemented!();
+    let _ = a == b && c == 5 && a == b;
+    let _ = a == b || c == 5 || a == b;
+    let _ = a == b && c == 5 && b == a;
+    let _ = a != b || !(a != b || c == d);
+    let _ = a != b && !(a != b && c == d);
+}
+
+fn issue3847(a: u32, b: u32) -> bool {
+    const THRESHOLD: u32 = 1_000;
+
+    if a < THRESHOLD && b >= THRESHOLD || a >= THRESHOLD && b < THRESHOLD {
+        return false;
+    }
+    true
+}
+
+fn issue4548() {
+    fn f(_i: u32, _j: u32) -> u32 {
+        unimplemented!();
+    }
+
+    let i = 0;
+    let j = 0;
+
+    if i != j && f(i, j) != 0 || i == j && f(i, j) != 1 {}
+}