From e8e51d1db4e37fcb8a2ec5c4b83798e19f8c780f Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Thu, 1 Nov 2018 10:13:28 +0900
Subject: [PATCH] Safe cast with return: fix false negative on lambda last
 statement #KT-27906 Fixed

---
 .../inspections/SafeCastWithReturnInspection.kt   |  7 ++++++-
 .../safeCastWithReturn/lambdaLastStatement.kt     |  7 +++++++
 .../safeCastWithReturn/lambdaLastStatement2.kt    |  6 ++++++
 .../lambdaLastStatement2.kt.after                 |  6 ++++++
 .../safeCastWithReturn/lambdaLastStatement3.kt    |  6 ++++++
 .../lambdaLastStatement3.kt.after                 |  6 ++++++
 .../inspections/LocalInspectionTestGenerated.java | 15 +++++++++++++++
 7 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement.kt
 create mode 100644 idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt
 create mode 100644 idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt.after
 create mode 100644 idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt
 create mode 100644 idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt.after

diff --git a/idea/src/org/jetbrains/kotlin/idea/inspections/SafeCastWithReturnInspection.kt b/idea/src/org/jetbrains/kotlin/idea/inspections/SafeCastWithReturnInspection.kt
index db6ce95fff4..2381dd39eb3 100644
--- a/idea/src/org/jetbrains/kotlin/idea/inspections/SafeCastWithReturnInspection.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/inspections/SafeCastWithReturnInspection.kt
@@ -30,7 +30,12 @@ class SafeCastWithReturnInspection : AbstractKotlinInspection() {
             if (KtPsiUtil.deparenthesize(parent.right) !is KtReturnExpression) return
 
             val context = expression.analyze(BodyResolveMode.PARTIAL_WITH_DIAGNOSTICS)
-            if (context[BindingContext.USED_AS_EXPRESSION, parent] == true) return
+            if (context[BindingContext.USED_AS_EXPRESSION, parent] == true) {
+                val lambda = expression.getStrictParentOfType<KtLambdaExpression>() ?: return
+                if (lambda.functionLiteral.bodyExpression?.statements?.lastOrNull() != parent) return
+                val call = lambda.getStrictParentOfType<KtCallExpression>() ?: return
+                if (context[BindingContext.USED_AS_EXPRESSION, call] == true) return
+            }
             if (context.diagnostics.forElement(expression.operationReference).any { it.factory == Errors.CAST_NEVER_SUCCEEDS }) return
 
             holder.registerProblem(
diff --git a/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement.kt b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement.kt
new file mode 100644
index 00000000000..ca2e1b731f0
--- /dev/null
+++ b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement.kt
@@ -0,0 +1,7 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun test(x: Any) {
+    val s = run {
+        <caret>x as? String ?: return
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt
new file mode 100644
index 00000000000..dc697b94706
--- /dev/null
+++ b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt
@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    run {
+        <caret>x as? String ?: return
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt.after b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt.after
new file mode 100644
index 00000000000..8e6c6f628e1
--- /dev/null
+++ b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt.after
@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    run {
+        if (x !is String) return
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt
new file mode 100644
index 00000000000..35c9a95e20a
--- /dev/null
+++ b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt
@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    run {
+        <caret>x as? String ?: return@run
+    }
+}
\ No newline at end of file
diff --git a/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt.after b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt.after
new file mode 100644
index 00000000000..1e06da38818
--- /dev/null
+++ b/idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt.after
@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    run {
+        if (x !is String) return@run
+    }
+}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
index 292ee595071..3c5037c88de 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java
@@ -5593,6 +5593,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/safeCastWithReturn/labeledReturn.kt");
         }
 
+        @TestMetadata("lambdaLastStatement.kt")
+        public void testLambdaLastStatement() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement.kt");
+        }
+
+        @TestMetadata("lambdaLastStatement2.kt")
+        public void testLambdaLastStatement2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement2.kt");
+        }
+
+        @TestMetadata("lambdaLastStatement3.kt")
+        public void testLambdaLastStatement3() throws Exception {
+            runTest("idea/testData/inspectionsLocal/safeCastWithReturn/lambdaLastStatement3.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("idea/testData/inspectionsLocal/safeCastWithReturn/simple.kt");