Smart completion: sometimes we can insert comma after vararg argument too

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/ExpectedInfos.kt

@@ -183,35 +183,46 @@ class ExpectedInfos(
 
             val expectedName = if (descriptor.hasSynthesizedParameterNames()) null else parameter.getName().asString()
 
+            val lastNonOptionalParam = parameters.lastOrNull { !it.hasDefaultValue() }
+
+            fun needCommaForParameter(parameter: ValueParameterDescriptor): Boolean {
+                if (parameter.hasDefaultValue()) return false // parameter is optional
+                if (parameter.getVarargElementType() != null) return false // vararg arguments list can be empty
+                // last non-optional parameter of functional type can be placed outside parenthesis:
+                if (parameter == lastNonOptionalParam && KotlinBuiltIns.isFunctionOrExtensionFunctionType(parameter.getType())) return false
+                return true
+            }
+
+            val tail = if (argumentName == null) {
+                if (parameter == parameters.last())
+                    Tail.RPARENTH //TODO: support square brackets
+                else if (parameters.dropWhile { it != parameter }.drop(1).any(::needCommaForParameter))
+                    Tail.COMMA
+                else
+                    null
+            }
+            else {
+                namedArgumentTail(argumentToParameter, argumentName, descriptor)
+            }
+
             val varargElementType = parameter.getVarargElementType()
             if (varargElementType != null) {
                 if (isFunctionLiteralArgument) continue
 
                 if (argumentName == null) {
-                    expectedInfos.add(ArgumentExpectedInfo(varargElementType, expectedName?.unpluralize(), null, descriptor, argumentPosition))
+                    expectedInfos.add(ArgumentExpectedInfo(varargElementType, expectedName?.unpluralize(),
+                                                           if (tail == Tail.RPARENTH) null else tail, descriptor, argumentPosition))
 
                     if (argumentIndex == parameters.indexOf(parameter)) {
-                        val tail = if (parameter == parameters.last()) Tail.RPARENTH else null
                         expectedInfos.add(ArgumentExpectedInfo(parameter.getType(), expectedName, tail, descriptor, argumentPosition, ItemOptions.STAR_PREFIX))
                     }
                 }
                 else {
-                    val tail = namedArgumentTail(argumentToParameter, argumentName, descriptor)
                     expectedInfos.add(ArgumentExpectedInfo(varargElementType, expectedName?.unpluralize(), tail, descriptor, argumentPosition))
                     expectedInfos.add(ArgumentExpectedInfo(parameter.getType(), expectedName, tail, descriptor, argumentPosition, ItemOptions.STAR_PREFIX))
                 }
             }
             else {
-                val lastNonOptionalParam = parameters.lastOrNull { !it.hasDefaultValue() }
-
-                fun needCommaForParameter(parameter: ValueParameterDescriptor): Boolean {
-                    if (parameter.hasDefaultValue()) return false // parameter is optional
-                    if (parameter.getVarargElementType() != null) return false // vararg arguments list can be empty
-                    // last non-optional parameter of functional type can be placed outside parenthesis:
-                    if (parameter == lastNonOptionalParam && KotlinBuiltIns.isFunctionOrExtensionFunctionType(parameter.getType())) return false
-                    return true
-                }
-
                 val parameterType = if (useHeuristicSignatures)
                     HeuristicSignatures.correctedParameterType(descriptor, parameter, moduleDescriptor, callElement.getProject()) ?: parameter.getType()
                 else
@@ -223,17 +234,6 @@ class ExpectedInfos(
                     }
                 }
                 else {
-                    val tail = if (argumentName == null) {
-                        if (parameter == parameters.last())
-                            Tail.RPARENTH //TODO: support square brackets
-                        else if (parameters.dropWhile { it != parameter }.drop(1).none(::needCommaForParameter))
-                            null
-                        else
-                            Tail.COMMA
-                    }
-                    else {
-                        namedArgumentTail(argumentToParameter, argumentName, descriptor)
-                    }
 
                     expectedInfos.add(ArgumentExpectedInfo(parameterType, expectedName, tail, descriptor, argumentPosition))
                 }

idea/idea-completion/testData/handlers/smart/SecondVararg.kt.after

@@ -1,7 +1,7 @@
 fun foo(vararg v1: Int, vararg v2: Char, s: String) { }
 
 fun bar(c: Char) {
-    foo(*intArrayOf(), c<caret>)
+    foo(*intArrayOf(), c, <caret>)
 }
 
 // ELEMENT: c

idea/idea-completion/testData/handlers/smart/VarargWithParameterAfter.kt

@@ -0,0 +1,7 @@
+fun foo(vararg strings: String, p: String){ }
+
+fun bar(s: String){
+    foo(<caret>)
+}
+
+// ELEMENT: s

idea/idea-completion/testData/handlers/smart/VarargWithParameterAfter.kt.after

@@ -0,0 +1,7 @@
+fun foo(vararg strings: String, p: String){ }
+
+fun bar(s: String){
+    foo(s, <caret>)
+}
+
+// ELEMENT: s

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/SmartCompletionHandlerTestGenerated.java

@@ -761,6 +761,12 @@ public class SmartCompletionHandlerTestGenerated extends AbstractSmartCompletion
         doTest(fileName);
     }
 
+    @TestMetadata("VarargWithParameterAfter.kt")
+    public void testVarargWithParameterAfter() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/smart/VarargWithParameterAfter.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("WhenElse.kt")
     public void testWhenElse() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/smart/WhenElse.kt");