KT-3503 Can't navigate to implementation of kotlin functions

#KT-3503 Fixed

idea/src/org/jetbrains/jet/plugin/search/KotlinDefinitionsSearcher.java

@@ -16,21 +16,24 @@
 
 package org.jetbrains.jet.plugin.search;
 
+import com.intellij.codeInsight.navigation.MethodImplementationsSearch;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.QueryExecutorBase;
 import com.intellij.openapi.util.Computable;
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiMethod;
 import com.intellij.psi.search.searches.ClassInheritorsSearch;
 import com.intellij.util.Processor;
-import com.intellij.util.Query;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.asJava.LightClassUtil;
 import org.jetbrains.jet.lang.psi.JetClass;
+import org.jetbrains.jet.lang.psi.JetNamedFunction;
 
 public class KotlinDefinitionsSearcher extends QueryExecutorBase<PsiElement, PsiElement> {
     @Override
-    public void processQuery(@NotNull final PsiElement queryParameters, @NotNull final Processor<PsiElement> consumer) {
+    public void processQuery(@NotNull final PsiElement queryParameters, @NotNull Processor<PsiElement> consumer) {
         if (queryParameters instanceof JetClass) {
             PsiClass psiClass = ApplicationManager.getApplication().runReadAction(new Computable<PsiClass>() {
                 @Override
@@ -39,13 +42,20 @@ public class KotlinDefinitionsSearcher extends QueryExecutorBase<PsiElement, Psi
                 }
             });
             if (psiClass != null) {
-                Query<PsiClass> query = ClassInheritorsSearch.search(psiClass, true);
-                query.forEach(new Processor<PsiClass>() {
-                    @Override
-                    public boolean process(PsiClass clazz) {
-                        return consumer.process(clazz);
-                    }
-                });
+                ContainerUtil.process(ClassInheritorsSearch.search(psiClass, true), consumer);
+            }
+        }
+
+        if (queryParameters instanceof JetNamedFunction) {
+            PsiMethod psiMethod = ApplicationManager.getApplication().runReadAction(new Computable<PsiMethod>() {
+                @Override
+                public PsiMethod compute() {
+                    return LightClassUtil.getLightClassMethod((JetNamedFunction) queryParameters);
+                }
+            });
+
+            if (psiMethod != null) {
+                ContainerUtil.process(MethodImplementationsSearch.getMethodImplementations(psiMethod), consumer);
             }
         }
     }

idea/testData/navigation/implementations/FunctionOverrideNavigation.kt

@@ -0,0 +1,21 @@
+package testing
+
+open class Base {
+    open fun <caret>test() {
+    }
+}
+
+open class SubBase: Base() {
+    override fun test() {
+
+    }
+}
+
+class SubSubBase: SubBase() {
+    override fun test() {
+    }
+}
+
+
+// REF: (in testing.SubBase).test()
+// REF: (in testing.SubSubBase).test()

idea/testData/navigation/implementations/multifile/ImplementFunInJava/ImplementFunInJava.java

@@ -0,0 +1,7 @@
+package testing.jj;
+
+public class JavaBase extends testing.kt.KotlinBase {
+    @Override
+    public void test() {
+    }
+}

idea/testData/navigation/implementations/multifile/ImplementFunInJava/ImplementFunInJava.kt

@@ -0,0 +1,7 @@
+package testing.kt
+
+open class KotlinBase {
+  open fun <caret>test() {}
+}
+
+// REF: (in testing.jj.JavaBase).test()

idea/testData/navigation/implementations/multifile/ImplementMethodInKotlin/ImplementMethodInKotlin.java

@@ -0,0 +1,5 @@
+public class BaseJava {
+    public void testMethod() {
+
+    }
+}

idea/testData/navigation/implementations/multifile/ImplementMethodInKotlin/ImplementMethodInKotlin.kt

@@ -0,0 +1,13 @@
+package testing.kt
+
+class TestFromJava() : BaseJava() {
+    override fun testMethod() {
+    }
+}
+
+fun test() {
+    BaseJava().testMethod<caret>()
+}
+
+// REF: (in testing.kt.TestFromJava).testMethod()
+// REF: (in BaseJava).testMethod()

idea/tests/org/jetbrains/jet/plugin/navigation/JetGotoImplementationMultifileTest.java

@@ -23,6 +23,10 @@ import org.jetbrains.jet.plugin.PluginTestCaseBase;
 import java.io.File;
 
 public class JetGotoImplementationMultifileTest extends CodeInsightTestCase {
+    public void testImplementFunInJava() throws Exception {
+        doKotlinJavaTest();
+    }
+
     public void testImplementKotlinClassInJava() throws Exception {
         doKotlinJavaTest();
     }
@@ -31,6 +35,10 @@ public class JetGotoImplementationMultifileTest extends CodeInsightTestCase {
         doKotlinJavaTest();
     }
 
+    public void testImplementMethodInKotlin() throws Exception {
+        doKotlinJavaTest();
+    }
+
     private void doKotlinJavaTest() throws Exception {
         doMultifileTest(getTestName(false) + ".kt", getTestName(false) + ".java");
     }

idea/tests/org/jetbrains/jet/plugin/navigation/JetGotoImplementationTest.java

@@ -19,6 +19,7 @@ package org.jetbrains.jet.plugin.navigation;
 import com.intellij.codeInsight.navigation.GotoTargetHandler;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.testFramework.LightCodeInsightTestCase;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.plugin.PluginTestCaseBase;
 
 import java.io.File;
@@ -32,6 +33,11 @@ public class JetGotoImplementationTest extends LightCodeInsightTestCase {
         doTest();
     }
 
+    public void testFunctionOverrideNavigation() {
+        doTest();
+    }
+
+    @NotNull
     @Override
     protected String getTestDataPath() {
         return new File(PluginTestCaseBase.getTestDataPathBase(), "/navigation/implementations").getPath() +