Ignore data flow info from assert calls

if assertions mode is not LEGACY.

This is done since assertions can be disabled (in both compile time and
runtime) and thus, the data flow info is not reliable anymore.
 #KT-24529: Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/CallResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
  * that can be found in the license/LICENSE.txt file.
  */
 
@@ -12,6 +12,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.builtins.FunctionTypesKt;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
+import org.jetbrains.kotlin.config.AnalysisFlag;
 import org.jetbrains.kotlin.config.LanguageFeature;
 import org.jetbrains.kotlin.config.LanguageVersionSettings;
 import org.jetbrains.kotlin.descriptors.*;
@@ -655,6 +656,7 @@ public class CallResolver {
             @NotNull ResolutionTask<D> resolutionTask,
             @NotNull TracingStrategy tracing
     ) {
+        DataFlowInfo initialInfo = context.dataFlowInfoForArguments.getResultInfo();
         if (context.checkArguments == CheckArgumentTypesMode.CHECK_VALUE_ARGUMENTS) {
             argumentTypeResolver.analyzeArgumentsAndRecordTypes(context, ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS);
         }
@@ -673,14 +675,32 @@ public class CallResolver {
             }
         }
 
+        OverloadResolutionResultsImpl<D> result;
         if (!(resolutionTask.resolutionKind instanceof NewResolutionOldInference.ResolutionKind.GivenCandidates)) {
             assert resolutionTask.name != null;
-            return newResolutionOldInference.runResolution(context, resolutionTask.name, resolutionTask.resolutionKind, tracing);
+            result = newResolutionOldInference.runResolution(context, resolutionTask.name, resolutionTask.resolutionKind, tracing);
         }
         else {
             assert resolutionTask.givenCandidates != null;
-            return newResolutionOldInference.runResolutionForGivenCandidates(context, tracing, resolutionTask.givenCandidates);
+            result = newResolutionOldInference.runResolutionForGivenCandidates(context, tracing, resolutionTask.givenCandidates);
         }
+
+        // in code like
+        //   assert(a!!.isEmpty())
+        //   a.length
+        // we should ignore data flow info from assert argument, since assertions can be disabled and
+        // thus it will lead to NPE in runtime otherwise
+        if (languageVersionSettings.getFlag(AnalysisFlag.getIgnoreDataFlowInAssert()) && result.isSingleResult()) {
+            D descriptor = result.getResultingDescriptor();
+            if (descriptor.getName().equals(Name.identifier("assert"))) {
+                DeclarationDescriptor declaration = descriptor.getContainingDeclaration();
+                if (declaration instanceof PackageFragmentDescriptor &&
+                    ((PackageFragmentDescriptor) declaration).getFqName().asString().equals("kotlin")) {
+                    context.dataFlowInfoForArguments.updateInfo(context.call.getValueArguments().get(0), initialInfo);
+                }
+            }
+        }
+        return result;
     }
 
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