KT-4893 Code completion should not show multiple functions with the same signature

#KT-4893 Fixed

compiler/frontend/src/org/jetbrains/kotlin/psi/JetValueArgumentName.java

@@ -18,16 +18,23 @@ package org.jetbrains.kotlin.psi;
 
 import com.intellij.lang.ASTNode;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.JetNodeTypes;
+import org.jetbrains.kotlin.name.Name;
 
-public class JetValueArgumentName extends JetElementImpl {
+public class JetValueArgumentName extends JetElementImpl implements ValueArgumentName {
     public JetValueArgumentName(@NotNull ASTNode node) {
         super(node);
     }
 
-    @Nullable @IfNotParsed
+    @Override
+    @NotNull
     public JetSimpleNameExpression getReferenceExpression() {
         return (JetSimpleNameExpression) findChildByType(JetNodeTypes.REFERENCE_EXPRESSION);
     }
+
+    @NotNull
+    @Override
+    public Name getAsName() {
+        return getReferenceExpression().getReferencedNameAsName();
+    }
 }

compiler/frontend/src/org/jetbrains/kotlin/psi/ValueArgument.kt

@@ -17,12 +17,13 @@
 package org.jetbrains.kotlin.psi
 
 import com.intellij.psi.impl.source.tree.LeafPsiElement
+import org.jetbrains.kotlin.name.Name
 
 public trait ValueArgument {
     IfNotParsed
     public fun getArgumentExpression(): JetExpression?
 
-    public fun getArgumentName(): JetValueArgumentName?
+    public fun getArgumentName(): ValueArgumentName?
 
     public fun isNamed(): Boolean
 
@@ -40,3 +41,8 @@ public trait FunctionLiteralArgument : ValueArgument {
 
     override fun getArgumentExpression(): JetExpression
 }
+
+public interface ValueArgumentName {
+    public val asName: Name
+    public val referenceExpression: JetSimpleNameExpression?
+}

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

@@ -155,9 +155,11 @@ public class ValueArgumentsToParametersMapper {
 
                 D candidate = candidateCall.getCandidateDescriptor();
 
-                JetSimpleNameExpression nameReference = argument.getArgumentName().getReferenceExpression();
-                ValueParameterDescriptor valueParameterDescriptor = parameterByName.get(nameReference.getReferencedNameAsName());
-                if (!candidate.hasStableParameterNames()) {
+                ValueArgumentName argumentName = argument.getArgumentName();
+                assert argumentName != null;
+                ValueParameterDescriptor valueParameterDescriptor = parameterByName.get(argumentName.getAsName());
+                JetReferenceExpression nameReference = argumentName.getReferenceExpression();
+                if (!candidate.hasStableParameterNames() && nameReference != null) {
                     report(NAMED_ARGUMENTS_NOT_ALLOWED.on(
                             nameReference,
                             candidate instanceof FunctionInvokeDescriptor ? INVOKE_ON_FUNCTION_TYPE : NON_KOTLIN_FUNCTION
@@ -165,14 +167,20 @@ public class ValueArgumentsToParametersMapper {
                 }
 
                 if (valueParameterDescriptor == null) {
-                    report(NAMED_PARAMETER_NOT_FOUND.on(nameReference, nameReference));
+                    if (nameReference != null) {
+                        report(NAMED_PARAMETER_NOT_FOUND.on(nameReference, nameReference));
+                    }
                     unmappedArguments.add(argument);
                     setStatus(WEAK_ERROR);
                 }
                 else {
-                    candidateCall.getTrace().record(REFERENCE_TARGET, nameReference, valueParameterDescriptor);
+                    if (nameReference != null) {
+                        candidateCall.getTrace().record(REFERENCE_TARGET, nameReference, valueParameterDescriptor);
+                    }
                     if (!usedParameters.add(valueParameterDescriptor)) {
-                        report(ARGUMENT_PASSED_TWICE.on(nameReference));
+                        if (nameReference != null) {
+                            report(ARGUMENT_PASSED_TWICE.on(nameReference));
+                        }
                         unmappedArguments.add(argument);
                         setStatus(WEAK_ERROR);
                     }

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/dynamicCalls.kt

@@ -182,7 +182,7 @@ object DynamicCallableDescriptors {
                     null,
                     index,
                     Annotations.EMPTY,
-                    arg.getArgumentName()?.getReferenceExpression()?.getReferencedNameAsName() ?: Name.identifier("p$index"),
+                    arg.getArgumentName()?.asName ?: Name.identifier("p$index"),
                     outType,
                     false,
                     varargElementType,

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/util/CallMaker.java

@@ -60,7 +60,7 @@ public class CallMaker {
         }
 
         @Override
-        public JetValueArgumentName getArgumentName() {
+        public ValueArgumentName getArgumentName() {
             return null;
         }