Potential fix for some random errors about "cannot choose between equals invoke functions".

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/results/OverloadingConflictResolver.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.resolve.calls.context.CheckArgumentTypesMode
 import org.jetbrains.kotlin.resolve.descriptorUtil.varargParameterPosition
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
+import java.lang.AssertionError
 import java.util.*
 
 class OverloadingConflictResolver<C : Any>(
@@ -63,7 +64,7 @@ class OverloadingConflictResolver<C : Any>(
         if (candidates.size == 1) return candidates
 
         val fixedCandidates = if (getVariableCandidates(candidates.first()) != null) {
-            findMaximallySpecificVariableAsFunctionCalls(candidates) ?: return candidates
+            findMaximallySpecificVariableAsFunctionCalls(candidates, isDebuggerContext) ?: return candidates
         }
         else {
             candidates
@@ -137,13 +138,15 @@ class OverloadingConflictResolver<C : Any>(
             }
 
     // null means ambiguity between variables
-    private fun findMaximallySpecificVariableAsFunctionCalls(candidates: Set<C>): Set<C>? {
+    private fun findMaximallySpecificVariableAsFunctionCalls(candidates: Set<C>, isDebuggerContext: Boolean): Set<C>? {
         val variableCalls = candidates.mapTo(newResolvedCallSet(candidates.size)) {
             getVariableCandidates(it) ?: throw AssertionError("Regular call among variable-as-function calls: $it")
         }
 
-        val maxSpecificVariableCall = findMaximallySpecificCall(variableCalls, false, false) ?: return null
+        val maxSpecificVariableCalls = chooseMaximallySpecificCandidates(variableCalls, CheckArgumentTypesMode.CHECK_VALUE_ARGUMENTS,
+                                                                        isDebuggerContext = isDebuggerContext, discriminateGenerics = false)
 
+        val maxSpecificVariableCall = maxSpecificVariableCalls.singleOrNull() ?: return null
         return candidates.filterTo(newResolvedCallSet(2)) {
             getVariableCandidates(it)!!.resultingDescriptor == maxSpecificVariableCall.resultingDescriptor
         }

compiler/testData/integration/ant/jvm/valWithInvoke/build.log.expected

@@ -0,0 +1,11 @@
+OUT:
+Buildfile: [TestData]/build.xml
+
+build:
+  [kotlinc] Compiling [[TestData]/test.kt] => [[Temp]/test.jar]
+     [exec] 6
+
+BUILD SUCCESSFUL
+Total time: [time]
+
+Return code: 0

compiler/testData/integration/ant/jvm/valWithInvoke/build.xml

@@ -0,0 +1,12 @@
+<project name="Ant Task Test" default="build">
+    <taskdef resource="org/jetbrains/kotlin/ant/antlib.xml" classpath="${kotlin.lib}/kotlin-ant.jar"/>
+
+    <target name="build">
+        <kotlinc src="${test.data}/test.kt" classpath="${test.data}/valInside.jar" output="${temp}/test.jar" nowarn="true" />
+
+        <exec executable="java">
+            <arg line="-classpath ${temp}/test.jar bar.TestKt"/>
+        </exec>
+    </target>
+
+</project>

compiler/testData/integration/ant/jvm/valWithInvoke/test.kt

@@ -0,0 +1,10 @@
+package bar
+
+@Suppress("REDECLARATION")
+val foo: Int = 6
+
+operator fun Int.invoke() = this
+
+fun main(args: Array<String>) {
+    println(foo())
+}

compiler/tests/org/jetbrains/kotlin/integration/AntTaskTestGenerated.java

@@ -131,6 +131,12 @@ public class AntTaskTestGenerated extends AbstractAntTaskTest {
         doTest(fileName);
     }
 
+    @TestMetadata("valWithInvoke")
+    public void testValWithInvoke() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/integration/ant/jvm/valWithInvoke/");
+        doTest(fileName);
+    }
+
     @TestMetadata("verbose")
     public void testVerbose() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/integration/ant/jvm/verbose/");