From 7b5c90ebaff688b5d3da1060e670d21705e0288b Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Thu, 29 Dec 2016 20:51:46 +0300
Subject: [PATCH] Correctly load multifile package parts from binaries

JvmPackagePartProvider should not just blindly load all multifile parts from
all libraries on the classpath, but only those from multifile classes which
shadow (come earlier on the classpath) other classes with the same name.
Otherwise if you have different versions of the same library (which uses
multifile classes) on the classpath, the compiler will see parts from both
versions. If some declaration have moved from one part to another, it's
possible to observe an overload resolution ambiguity error

 #KT-15287 Fixed
---
 .../cli/jvm/compiler/JvmPackagePartProvider.kt     | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/JvmPackagePartProvider.kt b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/JvmPackagePartProvider.kt
index 5fbb49017e5..4ae79a905b2 100644
--- a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/JvmPackagePartProvider.kt
+++ b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/JvmPackagePartProvider.kt
@@ -22,7 +22,6 @@ import com.intellij.util.SmartList
 import org.jetbrains.kotlin.cli.jvm.config.JvmClasspathRoot
 import org.jetbrains.kotlin.config.JVMConfigurationKeys
 import org.jetbrains.kotlin.descriptors.PackagePartProvider
-import org.jetbrains.kotlin.fileClasses.JvmFileClassUtil
 import org.jetbrains.kotlin.load.kotlin.ModuleMapping
 import org.jetbrains.kotlin.load.kotlin.PackageParts
 import java.io.EOFException
@@ -47,11 +46,18 @@ class JvmPackagePartProvider(
         val rootToPackageParts = getPackageParts(packageFqName)
         if (rootToPackageParts.isEmpty()) return emptyList()
 
-        val result = arrayListOf<String>()
+        val result = linkedSetOf<String>()
+        val visitedMultifileFacades = linkedSetOf<String>()
         for ((_, packageParts) in rootToPackageParts) {
-            result.addAll(packageParts.parts)
+            for (name in packageParts.parts) {
+                val facadeName = packageParts.getMultifileFacadeName(name)
+                if (facadeName == null || facadeName !in visitedMultifileFacades) {
+                    result.add(name)
+                }
+            }
+            packageParts.parts.mapNotNullTo(visitedMultifileFacades, packageParts::getMultifileFacadeName)
         }
-        return result.distinct()
+        return result.toList()
     }
 
     override fun findMetadataPackageParts(packageFqName: String): List<String> =