Component functions are indexed 1-based

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

@@ -139,7 +139,7 @@ public class ExpressionTypingVisitorForStatements extends ExpressionTypingVisito
         if (expressionReceiver == null) {
             return JetTypeInfo.create(null, context.dataFlowInfo);
         }
-        int componentIndex = 0;
+        int componentIndex = 1;
         for (JetMultiDeclarationEntry entry : multiDeclaration.getEntries()) {
             final Name componentName = Name.identifier("component" + componentIndex);
             componentIndex++;

compiler/testData/diagnostics/tests/declarationChecks/MultiDeclarationErrors.kt

@@ -1,13 +1,13 @@
 package a
 
 class MyClass {
-    fun component0(<!UNUSED_PARAMETER!>i<!>: Int) {}
+    fun component1(<!UNUSED_PARAMETER!>i<!>: Int) {}
 }
 
 class MyClass2 {}
 
-<!CONFLICTING_OVERLOADS!>fun MyClass2.component0()<!> = 1.2
-<!CONFLICTING_OVERLOADS!>fun MyClass2.component0()<!> = 1.3
+<!CONFLICTING_OVERLOADS!>fun MyClass2.component1()<!> = 1.2
+<!CONFLICTING_OVERLOADS!>fun MyClass2.component1()<!> = 1.3
 
 fun test(<!UNUSED_PARAMETER!>mc1<!>: MyClass, <!UNUSED_PARAMETER!>mc2<!>: MyClass2) {
     val (a, b) = <!COMPONENT_FUNCTION_MISSING, COMPONENT_FUNCTION_MISSING!>mc1<!>

compiler/testData/diagnostics/tests/declarationChecks/kt2631_MultipleDeclaration.kt

@@ -2,13 +2,13 @@
 package a
 
 class MyClass {
-    fun component0() = 1
-    fun component1() = "a"
+    fun component1() = 1
+    fun component2() = "a"
 }
 
 class MyClass2 {}
 
-fun MyClass2.component0() = 1.2
+fun MyClass2.component1() = 1.2
 
 fun test(<!UNUSED_PARAMETER!>mc1<!>: MyClass, <!UNUSED_PARAMETER!>mc2<!>: MyClass2) {
     val (a, b) = mc1