Fix map_entry suggests wrongly for insert with cfg-ed out code (#15800)

Closes #15781

changelog: [`map_entry`] fix wrong suggestions for insert with cfg-ed
out code

Author: samueltardieu

clippy_lints/src/entry.rs

@@ -4,7 +4,7 @@ use clippy_utils::ty::is_copy;
 use clippy_utils::visitors::for_each_expr;
 use clippy_utils::{
     SpanlessEq, can_move_expr_to_closure_no_visit, desugar_await, higher, is_expr_final_block_expr,
-    is_expr_used_or_unified, paths, peel_hir_expr_while,
+    is_expr_used_or_unified, paths, peel_hir_expr_while, span_contains_non_whitespace,
 };
 use core::fmt::{self, Write};
 use rustc_errors::Applicability;
@@ -167,7 +167,11 @@ impl<'tcx> LateLintPass<'tcx> for HashMapPass {
                     "if let {}::{entry_kind} = {map_str}.entry({key_str}) {body_str}",
                     map_ty.entry_path(),
                 ))
-            } else if let Some(insertion) = then_search.as_single_insertion() {
+            } else if let Some(insertion) = then_search.as_single_insertion()
+                && let span_in_between = then_expr.span.shrink_to_lo().between(insertion.call.span)
+                && let span_in_between = span_in_between.split_at(1).1
+                && !span_contains_non_whitespace(cx, span_in_between, true)
+            {
                 let value_str = snippet_with_context(cx, insertion.value.span, then_expr.span.ctxt(), "..", &mut app).0;
                 if contains_expr.negated {
                     if insertion.value.can_have_side_effects() {

tests/ui/entry.fixed

@@ -273,3 +273,13 @@ mod issue_16173 {
 }
 
 fn main() {}
+
+fn issue15781(m: &mut std::collections::HashMap<i32, i32>, k: i32, v: i32) {
+    fn very_important_fn() {}
+    m.entry(k).or_insert_with(|| {
+        //~^ map_entry
+        #[cfg(test)]
+        very_important_fn();
+        v
+    });
+}

tests/ui/entry.rs

@@ -279,3 +279,13 @@ mod issue_16173 {
 }
 
 fn main() {}
+
+fn issue15781(m: &mut std::collections::HashMap<i32, i32>, k: i32, v: i32) {
+    fn very_important_fn() {}
+    if !m.contains_key(&k) {
+        //~^ map_entry
+        #[cfg(test)]
+        very_important_fn();
+        m.insert(k, v);
+    }
+}

tests/ui/entry.stderr

@@ -246,5 +246,26 @@ LL +         e.insert(42);
 LL +     }
    |
 
-error: aborting due to 11 previous errors
+error: usage of `contains_key` followed by `insert` on a `HashMap`
+  --> tests/ui/entry.rs:285:5
+   |
+LL | /     if !m.contains_key(&k) {
+LL | |
+LL | |         #[cfg(test)]
+LL | |         very_important_fn();
+LL | |         m.insert(k, v);
+LL | |     }
+   | |_____^
+   |
+help: try
+   |
+LL ~     m.entry(k).or_insert_with(|| {
+LL +
+LL +         #[cfg(test)]
+LL +         very_important_fn();
+LL +         v
+LL +     });
+   |
+
+error: aborting due to 12 previous errors