Corrected explicit_counter_loop behavior with nested loops

Author: JoshMcguigan

clippy_lints/src/loops.rs

@@ -1942,8 +1942,7 @@ impl<'a, 'tcx> Visitor<'tcx> for IncrementVisitor<'a, 'tcx> {
                 }
             }
         } else if is_loop(expr) {
-            self.states.clear();
-            self.done = true;
+            walk_expr(self, expr);
             return;
         } else if is_conditional(expr) {
             self.depth += 1;

tests/ui/for_loop.rs

@@ -612,5 +612,27 @@ mod issue_1219 {
             }
             println!("{}", count);
         }
+
+        // should trigger the lint because the count is not conditional
+        let text = "banana";
+        let mut count = 0;
+        for ch in text.chars() {
+            count += 1;
+            for i in 0..2 {
+                let _ = 123;
+            }
+            println!("{}", count);
+        }
+
+        // should not trigger the lint because the count is incremented multiple times
+        let text = "banana";
+        let mut count = 0;
+        for ch in text.chars() {
+            count += 1;
+            for i in 0..2 {
+                count += 1;
+            }
+            println!("{}", count);
+        }
     }
 }

tests/ui/for_loop.stderr

@@ -493,5 +493,11 @@ error: the variable `count` is used as a loop counter. Consider using `for (coun
 608 |         for ch in text.chars() {
     |                   ^^^^^^^^^^^^
 
-error: aborting due to 60 previous errors
+error: the variable `count` is used as a loop counter. Consider using `for (count, item) in text.chars().enumerate()` or similar iterators
+   --> $DIR/for_loop.rs:619:19
+    |
+619 |         for ch in text.chars() {
+    |                   ^^^^^^^^^^^^
+
+error: aborting due to 61 previous errors