KT-10706: do not report IMPLICIT_CAST_TO_ANY on expressions of type Nothing

compiler/frontend/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProvider.java

@@ -744,7 +744,8 @@ public class ControlFlowInformationProvider {
             for (KtExpression branchExpression : branchExpressions) {
                 if (branchExpression == null) continue;
                 KotlinType branchType = trace.getType(branchExpression);
-                assert branchType != null : "Branch expression type should be non-null";
+                if (branchType == null) continue;
+                if (KotlinBuiltIns.isNothing(branchType)) continue;
                 trace.report(IMPLICIT_CAST_TO_ANY.on(getResultingExpression(branchExpression), branchType, expressionType));
             }
         }

compiler/testData/diagnostics/tests/controlStructures/kt10706.kt

@@ -0,0 +1,12 @@
+fun TODO(): Nothing = null!!
+
+fun fn(c: Char?): Any? =
+        if (c == null) TODO()
+        else when (<!DEBUG_INFO_SMARTCAST!>c<!>) {
+            'a' -> when (<!DEBUG_INFO_SMARTCAST!>c<!>) {
+                'B' -> <!IMPLICIT_CAST_TO_ANY!>1<!>
+                'C' -> <!IMPLICIT_CAST_TO_ANY!>"sdf"<!>
+                else -> TODO()
+            }
+            else -> TODO()
+        }

compiler/testData/diagnostics/tests/controlStructures/kt10706.txt

@@ -0,0 +1,4 @@
+package
+
+public fun TODO(): kotlin.Nothing
+public fun fn(/*0*/ c: kotlin.Char?): kotlin.Any?

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -3360,6 +3360,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("kt10706.kt")
+            public void testKt10706() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/controlStructures/kt10706.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("kt1075.kt")
             public void testKt1075() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/controlStructures/kt1075.kt");