Fix issue with mismatched parens in suggestion

Author: Evan Typanski

clippy_lints/src/ranges.rs

@@ -296,10 +296,15 @@ fn check_possible_range_contains(
     }
 
     // If the LHS is the same operator, we have to recurse to get the "real" RHS, since they have
-    // the same operator precedence.
-    if let ExprKind::Binary(ref lhs_op, _left, new_lhs) = left.kind {
-        if op == lhs_op.node {
-            let new_span = Span::new(new_lhs.span.lo(), right.span.hi(), expr.span.ctxt(), expr.span.parent());
+    // the same operator precedence
+    if_chain! {
+        if let ExprKind::Binary(ref lhs_op, _left, new_lhs) = left.kind;
+        if op == lhs_op.node;
+        let new_span = Span::new(new_lhs.span.lo(), right.span.hi(), expr.span.ctxt(), expr.span.parent());
+        if let Some(snip) = &snippet_opt(cx, new_span);
+        // Do not continue if we have mismatched number of parens, otherwise the suggestion is wrong
+        if snip.matches('(').count() == snip.matches(')').count();
+        then {
             check_possible_range_contains(cx, op, new_lhs, right, expr, new_span);
         }
     }

tests/ui/range_contains.fixed

@@ -54,6 +54,8 @@ fn main() {
     let z = 42;
     (0..=10).contains(&x) && (0..=10).contains(&z);
     !(0..10).contains(&x) || !(0..10).contains(&z);
+    // Make sure operators in parens don't give a breaking suggestion
+    ((x % 2 == 0) || (x < 0)) || (x >= 10);
 }
 
 // Fix #6373

tests/ui/range_contains.rs

@@ -54,6 +54,8 @@ fn main() {
     let z = 42;
     (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10);
     (x < 0) || (x >= 10) || (z < 0) || (z >= 10);
+    // Make sure operators in parens don't give a breaking suggestion
+    ((x % 2 == 0) || (x < 0)) || (x >= 10);
 }
 
 // Fix #6373