Added test for obsolete bug and removed workaround in code.

compiler/testData/diagnostics/tests/overload/kt2493.kt

@@ -0,0 +1,19 @@
+trait A
+trait B
+
+fun <R: A> R.f() {
+}
+
+fun <R: B> R.f() {
+}
+
+class AImpl: A
+class BImpl: B
+
+class C: A, B
+
+fun main(args: Array<String>) {
+    AImpl().f()
+    BImpl().f()
+    C().<!CANNOT_COMPLETE_RESOLVE!>f<!>()
+}

compiler/testData/diagnostics/tests/overload/kt2493.txt

@@ -0,0 +1,38 @@
+package
+
+internal fun main(/*0*/ args: kotlin.Array<kotlin.String>): kotlin.Unit
+internal fun </*0*/ R : A> R.f(): kotlin.Unit
+internal fun </*0*/ R : B> R.f(): kotlin.Unit
+
+internal trait A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class AImpl : A {
+    public constructor AImpl()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal trait B {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class BImpl : B {
+    public constructor BImpl()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class C : A, B {
+    public constructor C()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -8437,6 +8437,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("kt2493.kt")
+            public void testKt2493() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/overload/kt2493.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("kt7068.kt")
             public void testKt7068() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/overload/kt7068.kt");

libraries/kotlin-jdbc/src/main/kotlin/kotlin/jdbc/Connections.kt

@@ -37,7 +37,7 @@ fun <T> Connection.use(block : (Connection) -> T) : T {
 fun <T> Connection.statement(block: (Statement) -> T): T {
     val statement = createStatement()
     if (statement != null) {
-        return statement.useSql(block)
+        return statement.use(block)
     } else {
         throw IllegalStateException("No Statement returned from $this")
     }

libraries/kotlin-jdbc/src/main/kotlin/kotlin/jdbc/DataSources.kt

@@ -7,7 +7,7 @@ import kotlin.template.StringTemplate
 /**
  * Processes a connection from the pool using the given function block
  */
-fun <T> DataSource.useDataSource(block : (Connection) -> T): T { // TODO rename to "use" when KT-2493 is fixed
+fun <T> DataSource.use(block : (Connection) -> T): T {
     val connection = getConnection()
     if (connection != null) {
         try {
@@ -24,33 +24,33 @@ fun <T> DataSource.useDataSource(block : (Connection) -> T): T { // TODO rename
  * Helper method to process a statement on this collection
  */
 fun <T> DataSource.statement(block: (Statement) -> T): T {
-    return useDataSource{ it.statement(block) }
+    return use { it.statement(block) }
 }
 
 /**
  * Perform an SQL update on the connection
  */
 fun DataSource.update(sql: String): Int {
-    return useDataSource{ it.update(sql) }
+    return use { it.update(sql) }
 }
 
 /**
  * Perform a query on the connection and processes the result set with a function
  */
 fun <T> DataSource.query(sql: String, block: (ResultSet) -> T): T {
-    return useDataSource{ it.query(sql, block) }
+    return use { it.query(sql, block) }
 }
 
 /**
  * Performs the update using the given SQL using a [[StringTemplate]]
  */
 fun DataSource.update(template : StringTemplate) : Int {
-    return useDataSource{ it.update(template) }
+    return use { it.update(template) }
 }
 
 /**
  * Perform a query on the connection using the SQL from the [[StringTemplate]] and processes the result set with a function
  */
 fun <T> DataSource.query(template : StringTemplate, resultBlock : (ResultSet) -> T) : T {
-    return useDataSource{ it.query(template, resultBlock) }
+    return use { it.query(template, resultBlock) }
 }

libraries/kotlin-jdbc/src/main/kotlin/kotlin/jdbc/Statements.kt

@@ -8,7 +8,7 @@ import java.sql.Statement
 /**
  * Uses the statement with the given block then closes the statement
  */
-fun <T, S : Statement> S.useSql(block : (S) -> T) : T { // TODO rename to "use" when KT-2493 is fixed
+fun <T, S : Statement> S.use(block : (S) -> T) : T {
     try {
         return block(this)
     } finally {