diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
index edbe66821c1..83ee4713460 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CandidateResolver.java
@@ -578,7 +578,7 @@ public class CandidateResolver {
         CallResolutionContext<?> newContext = context.replaceBindingTrace(traceToResolveArgument).replaceExpectedType(expectedType);
         JetTypeInfo typeInfoForCall = argumentTypeResolver.getArgumentTypeInfo(argumentExpression, newContext,
                                                                                resolveFunctionArgumentBodies, traceToResolveArgument);
-        JetType type = typeInfoForCall.getType();
+        JetType type = updateResultTypeForSmartCasts(typeInfoForCall.getType(), argumentExpression, context);
         constraintSystem.addSubtypeConstraint(type, effectiveExpectedType, ConstraintPosition.getValueParameterPosition(
                 valueParameterDescriptor.getIndex()));
         if (isErrorType != null) {
@@ -586,6 +586,22 @@ public class CandidateResolver {
         }
     }
 
+    @Nullable
+    private static JetType updateResultTypeForSmartCasts(
+            @Nullable JetType type,
+            @Nullable JetExpression argumentExpression,
+            @NotNull CallCandidateResolutionContext<?> context
+    ) {
+        if (argumentExpression == null || type == null) return type;
+
+        DataFlowValue dataFlowValue =
+                DataFlowValueFactory.INSTANCE.createDataFlowValue(argumentExpression, type, context.trace.getBindingContext());
+        Set<JetType> possibleTypes = context.dataFlowInfo.getPossibleTypes(dataFlowValue);
+        if (possibleTypes.isEmpty()) return type;
+
+        return TypeUtils.intersect(JetTypeChecker.INSTANCE, possibleTypes);
+    }
+
     private <D extends CallableDescriptor> ValueArgumentsCheckingResult checkAllValueArguments(
             @NotNull CallCandidateResolutionContext<D> context,
             @NotNull CallResolverUtil.ResolveArgumentsMode resolveFunctionArgumentBodies) {
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsUtil.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsUtil.java
index c5bc25246dc..fb0deafb134 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsUtil.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsUtil.java
@@ -110,6 +110,12 @@ public class ConstraintsUtil {
     @Nullable
     private static JetType commonSupertype(@NotNull Collection<JetType> lowerBounds) {
         if (lowerBounds.isEmpty()) return null;
+        if (lowerBounds.size() == 1) {
+            JetType type = lowerBounds.iterator().next();
+            if (type.getConstructor() instanceof IntersectionTypeConstructor) {
+                return commonSupertype(type.getConstructor().getSupertypes());
+            }
+        }
         return CommonSupertypes.commonSupertype(lowerBounds);
     }
 
@@ -124,6 +130,7 @@ public class ConstraintsUtil {
             @NotNull TypeConstraints typeConstraints
     ) {
         if (suggestion == null) return false;
+        if (!suggestion.getConstructor().isDenotable()) return false;
         if (typeConstraints.getExactBounds().size() > 1) return false;
 
         for (JetType exactBound : typeConstraints.getExactBounds()) {
diff --git a/compiler/testData/diagnostics/tests/smartCasts/inference/intersectionTypes.kt b/compiler/testData/diagnostics/tests/smartCasts/inference/intersectionTypes.kt
new file mode 100644
index 00000000000..cdb34a140d5
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/smartCasts/inference/intersectionTypes.kt
@@ -0,0 +1,56 @@
+package a
+
+fun <T> id(t: T): T = t
+
+fun <T> two(u: T, <!UNUSED_PARAMETER!>v<!>: T): T = u
+
+fun <T> three(<!UNUSED_PARAMETER!>a<!>: T, <!UNUSED_PARAMETER!>b<!>: T, c: T): T = c
+
+trait A
+trait B: A
+trait C: A
+
+fun test(a: A, b: B, c: C) {
+    if (a is B && a is C) {
+        val d: C = id(a)
+        val e: Any = id(a)
+        val f = id(a)
+        val g = two(a, b)
+        g: B
+        g: A
+
+        val h: Any = two(a, b)
+
+        val k = three(a, b, c)
+        k: A
+        <!TYPE_MISMATCH!>k<!>: B
+        val l: Int = <!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>three<!>(a, b, c)
+        
+        use(d, e, f, g, h, k, l)
+    }
+}
+
+fun <T> foo(t: T, <!UNUSED_PARAMETER!>l<!>: MutableList<T>): T = t
+
+fun testErrorMessages(a: A, ml: MutableList<String>) {
+    if (a is B && a is C) {
+        <!TYPE_INFERENCE_CONFLICTING_SUBSTITUTIONS!>foo<!>(a, ml)
+    }
+
+    if(a is C) {
+        <!TYPE_INFERENCE_CONFLICTING_SUBSTITUTIONS!>foo<!>(a, ml)
+    }
+}
+
+fun rr(s: String?) {
+    if (s != null) {
+        val l = arrayListOf("", s)
+        l: MutableList<String>
+        <!TYPE_MISMATCH!>l<!>: MutableList<String?>
+    }
+}
+
+//from library
+fun arrayListOf<T>(vararg <!UNUSED_PARAMETER!>values<!>: T): MutableList<T> = throw Exception()
+
+fun use(vararg a: Any) = a
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/smartCasts/inference/kt1355.kt b/compiler/testData/diagnostics/tests/smartCasts/inference/kt1355.kt
new file mode 100644
index 00000000000..a4bd1ee4c63
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/smartCasts/inference/kt1355.kt
@@ -0,0 +1,40 @@
+//KT-1355 Type inference fails with autocast and generic function
+//tests for Map.set
+package a
+
+import java.util.HashMap
+
+fun foo(map: MutableMap<Int, String>, value: String?) {
+    if (value != null) {
+        map.put(1, value) //ok
+        map.set(1, value) //type inference failed
+        map[1] = value    //type inference failed
+    }
+}
+
+//---------------------------
+
+public data open class Tag(public var tagName: String) {
+    public val attributes: MutableMap<String, String> = HashMap<String, String>()
+    public val contents: MutableList<Tag> = arrayListOf()
+
+    public var id: String?
+        get() = attributes["id"]
+        set(value) {
+            if(value == null) {
+                attributes.remove("id")
+            }
+            else {
+                attributes["id"] = value<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
+                attributes["id"] = value
+            }
+        }
+}
+
+
+//from library
+fun <K, V> MutableMap<K, V>.set(key : K, value : V) = this.put(key, value)
+
+fun arrayListOf<T>(vararg <!UNUSED_PARAMETER!>values<!>: T): MutableList<T> = throw Exception()
+
+
diff --git a/compiler/testData/diagnostics/tests/smartCasts/inference/kt2746.kt b/compiler/testData/diagnostics/tests/smartCasts/inference/kt2746.kt
new file mode 100644
index 00000000000..4bddbccb38c
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/smartCasts/inference/kt2746.kt
@@ -0,0 +1,19 @@
+//KT-2746 Do autocasts in inference
+import java.util.HashMap
+
+class C<T>(t :T)
+
+fun test1(a: Any) {
+    if (a is String) {
+        val <!UNUSED_VARIABLE!>c<!>: C<String> = C(a)
+    }
+}
+
+
+fun f<T>(t :T): C<T> = C(t)
+
+fun test2(a: Any) {
+    if (a is String) {
+        val <!UNUSED_VARIABLE!>c1<!>: C<String> = f(a)
+    }
+}
diff --git a/compiler/testData/diagnostics/tests/smartCasts/inference/kt2851.kt b/compiler/testData/diagnostics/tests/smartCasts/inference/kt2851.kt
new file mode 100644
index 00000000000..e6147254056
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/smartCasts/inference/kt2851.kt
@@ -0,0 +1,20 @@
+//KT-2851 Type inference failed passing in not-null after smart-cast value in Pair
+package a
+
+fun main(args: Array<String>) {
+    val value: String? = ""
+    if (value != null) {
+        foo(Pair("val", value))
+        foo(Pair("val", value<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>))
+        foo(Pair<String, String>("val", value))
+    }
+}
+
+fun foo(<!UNUSED_PARAMETER!>map<!>: Pair<String, String>) {}
+
+
+//from library
+public class Pair<out A, out B> (
+        public val first: A,
+        public val second: B
+)
diff --git a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
index 89ecf10b247..cd4c849cd16 100644
--- a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
@@ -5070,6 +5070,7 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
         }
         
         @TestMetadata("compiler/testData/diagnostics/tests/smartCasts")
+        @InnerTestClasses({SmartCasts.Inference.class})
         public static class SmartCasts extends AbstractDiagnosticsTestWithEagerResolve {
             public void testAllFilesPresentInSmartCasts() throws Exception {
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.GenerateTests", new File("compiler/testData/diagnostics/tests/smartCasts"), Pattern.compile("^(.+)\\.kt$"), true);
@@ -5115,6 +5116,40 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/smartCasts/thisWithLabelAsReceiverPart.kt");
             }
             
+            @TestMetadata("compiler/testData/diagnostics/tests/smartCasts/inference")
+            public static class Inference extends AbstractDiagnosticsTestWithEagerResolve {
+                public void testAllFilesPresentInInference() throws Exception {
+                    JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.GenerateTests", new File("compiler/testData/diagnostics/tests/smartCasts/inference"), Pattern.compile("^(.+)\\.kt$"), true);
+                }
+                
+                @TestMetadata("intersectionTypes.kt")
+                public void testIntersectionTypes() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/smartCasts/inference/intersectionTypes.kt");
+                }
+                
+                @TestMetadata("kt1355.kt")
+                public void testKt1355() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/smartCasts/inference/kt1355.kt");
+                }
+                
+                @TestMetadata("kt2746.kt")
+                public void testKt2746() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/smartCasts/inference/kt2746.kt");
+                }
+                
+                @TestMetadata("kt2851.kt")
+                public void testKt2851() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/smartCasts/inference/kt2851.kt");
+                }
+                
+            }
+            
+            public static Test innerSuite() {
+                TestSuite suite = new TestSuite("SmartCasts");
+                suite.addTestSuite(SmartCasts.class);
+                suite.addTestSuite(Inference.class);
+                return suite;
+            }
         }
         
         @TestMetadata("compiler/testData/diagnostics/tests/substitutions")
@@ -5345,7 +5380,7 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
             suite.addTestSuite(Scopes.class);
             suite.addTestSuite(SenselessComparison.class);
             suite.addTestSuite(Shadowing.class);
-            suite.addTestSuite(SmartCasts.class);
+            suite.addTest(SmartCasts.innerSuite());
             suite.addTestSuite(Substitutions.class);
             suite.addTestSuite(Subtyping.class);
             suite.addTestSuite(ThisAndSuper.class);