EA-40964

Don't access elements of an empty array

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java

@@ -1437,7 +1437,9 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
 
         List<JetExpression> indices = arrayAccessExpression.getIndexExpressions();
         // The accumulated data flow info of all index expressions is saved on the last index
-        dataFlowInfo = facade.getTypeInfo(indices.get(indices.size() - 1), context).getDataFlowInfo();
+        if (!indices.isEmpty()) {
+            dataFlowInfo = facade.getTypeInfo(indices.get(indices.size() - 1), context).getDataFlowInfo();
+        }
 
         if (!isGet) {
             dataFlowInfo = facade.getTypeInfo(rightHandSide, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();

compiler/testData/diagnostics/tests/regressions/ea40964.kt

@@ -0,0 +1,8 @@
+package checkFiles
+
+import java.util.HashMap
+
+fun main(args: Array<String>) {
+    val hashMap = HashMap<String, String>()
+    hashMap[<!SYNTAX!><!>]
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -2955,6 +2955,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/regressions/DoubleDefine.kt");
             }
             
+            @TestMetadata("ea40964.kt")
+            public void testEa40964() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/regressions/ea40964.kt");
+            }
+            
             @TestMetadata("ErrorsOnIbjectExpressionsAsParameters.kt")
             public void testErrorsOnIbjectExpressionsAsParameters() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/regressions/ErrorsOnIbjectExpressionsAsParameters.kt");