"Add missing component" intention: fix it works correctly if entries is empty

#KT-36094 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/AddMissingDestructuringIntention.kt

@@ -40,8 +40,9 @@ class AddMissingDestructuringIntention :
             filter = NewDeclarationNameValidator(element.parent.parent, null, NewDeclarationNameValidator.Target.VARIABLES)
         )
 
-        val newEntries = entries.joinToString(postfix = ", ") { it.text } +
-                primaryParameters.asSequence().drop(entries.size).joinToString {
+        val entriesSize = entries.size
+        val newEntries = entries.joinToString(postfix = if (entriesSize == 0) "" else ", ") { it.text } +
+                primaryParameters.asSequence().drop(entriesSize).joinToString {
                     KotlinNameSuggester.suggestNameByName(it.name.asString(), nameValidator)
                 }
         val initializer = element.initializer ?: return

idea/testData/intentions/addMissingDestructuring/empty.kt

@@ -0,0 +1,5 @@
+data class Foo(val a: String, val b: String, val c: String)
+
+fun bar(f: Foo) {
+    val (<caret>) = f
+}

idea/testData/intentions/addMissingDestructuring/empty.kt.after

@@ -0,0 +1,5 @@
+data class Foo(val a: String, val b: String, val c: String)
+
+fun bar(f: Foo) {
+    val (a, b, c) = f
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -1142,6 +1142,11 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/intentions/addMissingDestructuring"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), null, true);
         }
 
+        @TestMetadata("empty.kt")
+        public void testEmpty() throws Exception {
+            runTest("idea/testData/intentions/addMissingDestructuring/empty.kt");
+        }
+
         @TestMetadata("notAvailable.kt")
         public void testNotAvailable() throws Exception {
             runTest("idea/testData/intentions/addMissingDestructuring/notAvailable.kt");