Non-imported extensions from different packages do not shadow each other

idea/ide-common/src/org/jetbrains/kotlin/idea/util/ShadowedDeclarationsFilter.kt

@@ -19,6 +19,8 @@ package org.jetbrains.kotlin.idea.util
 import com.intellij.openapi.project.Project
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.di.InjectorForMacros
+import org.jetbrains.kotlin.idea.imports.importableFqName
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DelegatingBindingTrace
@@ -34,7 +36,8 @@ import org.jetbrains.kotlin.resolve.scopes.ChainedScope
 import org.jetbrains.kotlin.resolve.scopes.ExplicitImportsScope
 import org.jetbrains.kotlin.resolve.validation.SymbolUsageValidator
 import org.jetbrains.kotlin.types.TypeUtils
-import java.util.*
+import java.util.ArrayList
+import java.util.HashSet
 
 public class ShadowedDeclarationsFilter(
         private val bindingContext: BindingContext,
@@ -64,7 +67,7 @@ public class ShadowedDeclarationsFilter(
         val call = expression.getCall(bindingContext) ?: return nonImportedDeclarations
 
         val notShadowed = nonImportedDeclarations
-                .groupBy { signature(it) }
+                .groupBy { signature(it) to packageName(it) } // same signature non-imported declarations from different packages do not shadow each other
                 .values()
                 .flatMapTo(HashSet<DeclarationDescriptor>()) { group ->
                     filterEqualSignatureGroup(group + importedDeclarations, call, descriptorsToImport = group)
@@ -80,6 +83,8 @@ public class ShadowedDeclarationsFilter(
         }
     }
 
+    private fun packageName(descriptor: DeclarationDescriptor) = descriptor.importableFqName?.parent()
+
     private fun <TDescriptor : DeclarationDescriptor> filterEqualSignatureGroup(
             descriptors: Collection<TDescriptor>,
             call: Call,

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -225,7 +225,6 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
 
     protected fun getTopLevelExtensions(): Collection<CallableDescriptor> {
         val extensions = indicesHelper.getCallableTopLevelExtensions({ prefixMatcher.prefixMatches(it) }, reference!!.expression)
-        //TODO: it filters out too much
         return ShadowedDeclarationsFilter(bindingContext, moduleDescriptor, project).filterNonImported(extensions, referenceVariants, reference.expression)
     }
 

idea/idea-completion/testData/basic/multifile/MoreSpecificExtensionInDifferentPackage/MoreSpecificExtensionInDifferentPackage.kt

@@ -0,0 +1,11 @@
+package ppp
+
+class C {
+    fun foo() {
+        xx<caret>
+    }
+}
+
+// EXIST: { lookupString: "xxx", itemText: "xxx", tailText: "() for Any in dependency1", typeText: "Int" }
+// EXIST: { lookupString: "xxx", itemText: "xxx", tailText: "() for C in dependency2", typeText: "Int" }
+// NOTHING_ELSE

idea/idea-completion/testData/basic/multifile/MoreSpecificExtensionInDifferentPackage/MoreSpecificExtensionInDifferentPackage2.dependency1.kt

@@ -0,0 +1,3 @@
+package dependency1
+
+fun Any.xxx(): Int = 1

idea/idea-completion/testData/basic/multifile/MoreSpecificExtensionInDifferentPackage/MoreSpecificExtensionInDifferentPackage2.dependency2.kt

@@ -0,0 +1,3 @@
+package dependency2
+
+fun ppp.C.xxx(): Int = 1

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/MultiFileJvmBasicCompletionTestGenerated.java

@@ -113,6 +113,12 @@ public class MultiFileJvmBasicCompletionTestGenerated extends AbstractMultiFileJ
         doTest(fileName);
     }
 
+    @TestMetadata("MoreSpecificExtensionInDifferentPackage")
+    public void testMoreSpecificExtensionInDifferentPackage() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/multifile/MoreSpecificExtensionInDifferentPackage/");
+        doTest(fileName);
+    }
+
     @TestMetadata("MoreSpecificExtensionIsPrivate")
     public void testMoreSpecificExtensionIsPrivate() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/multifile/MoreSpecificExtensionIsPrivate/");