Fixed a bug in import insertion algorithm

idea/src/org/jetbrains/kotlin/idea/quickfix/ImportInsertHelperImpl.kt

@@ -243,13 +243,16 @@ public class ImportInsertHelperImpl : ImportInsertHelper {
                     .filter(::isVisible)
                     .map { it.getName() }
 
-            val aliasNames = imports.map { it.getImportedName() }.filterNotNull().toSet()
-            var conflictCandidates: List<ClassifierDescriptor> = classNamesToImport
-                    .filter { it.asString() !in aliasNames }
+            val topLevelScope = resolutionFacade.getFileTopLevelScope(file)
+            val conflictCandidates: List<ClassifierDescriptor> = classNamesToImport
                     .flatMap {
                         importedScopes.map { scope -> scope.getClassifier(it) }.filterNotNull()
                     }
-                    .filter(::isVisible)
+                    .filter { importedClass ->
+                        isVisible(importedClass)
+                            && topLevelScope.getClassifier(importedClass.getName()) == importedClass /* check that class is really imported */
+                            && imports.all { it.getImportPath() != ImportPath(importedClass.importableFqNameSafe, false)  } /* and not yet imported explicitly */
+                    }
             val conflicts = detectNeededImports(conflictCandidates)
 
             val addedImport = addImport(parentFqName, true)
@@ -288,6 +291,8 @@ public class ImportInsertHelperImpl : ImportInsertHelper {
                 val topLevelScope = resolutionFacade.getFileTopLevelScope(file)
                 val name = target.getName()
 
+                // check if there is a conflicting class imported with * import
+                // (not with explicit import - explicit imports are checked before this method invocation)
                 val classifier = topLevelScope.getClassifier(name)
                 if (classifier != null && detectNeededImports(listOf(classifier)).isNotEmpty()) {
                     return false

idea/testData/addImport/ConflictingNameAppearsAndHasUsage6.dependency.kt

@@ -0,0 +1,3 @@
+package dependency
+
+fun String.Date(p: Int) {}

idea/testData/addImport/ConflictingNameAppearsAndHasUsage6.kt

@@ -0,0 +1,7 @@
+// IMPORT: java.util.ArrayList
+package p
+
+import java.sql.*
+import dependency.Date // import of function does not affect class name conflict
+
+val d = Date(1)

idea/testData/addImport/ConflictingNameAppearsAndHasUsage6.kt.after

@@ -0,0 +1,9 @@
+// IMPORT: java.util.ArrayList
+package p
+
+import java.sql.*
+import dependency.Date // import of function does not affect class name conflict
+import java.util.*
+import java.sql.Date
+
+val d = Date(1)

idea/tests/org/jetbrains/kotlin/addImport/AddImportTestGenerated.java

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.addImport;
 
 import com.intellij.testFramework.TestDataPath;
+import org.jetbrains.kotlin.test.InnerTestClasses;
 import org.jetbrains.kotlin.test.JUnit3RunnerWithInners;
 import org.jetbrains.kotlin.test.JetTestUtils;
 import org.jetbrains.kotlin.test.TestMetadata;
@@ -95,6 +96,12 @@ public class AddImportTestGenerated extends AbstractAddImportTest {
         doTest(fileName);
     }
 
+    @TestMetadata("ConflictingNameAppearsAndHasUsage6.kt")
+    public void testConflictingNameAppearsAndHasUsage6() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/addImport/ConflictingNameAppearsAndHasUsage6.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("ConflictingNameAppearsButUsageIsQualified.kt")
     public void testConflictingNameAppearsButUsageIsQualified() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/testData/addImport/ConflictingNameAppearsButUsageIsQualified.kt");