Prefer platform specific declarations when searching for library sources

Untested: test infrastructure needed

 #KT-23223 Fixed

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/navigation/SourceNavigationHelper.kt

@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.debugText.getDebugText
 import org.jetbrains.kotlin.resolve.TargetPlatform
+import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
 
 object SourceNavigationHelper {
     private val LOG = Logger.getInstance(SourceNavigationHelper::class.java)
@@ -50,23 +51,18 @@ object SourceNavigationHelper {
         SourceNavigationHelper.forceResolve = forceResolve
     }
 
-    private fun targetScope(declaration: KtNamedDeclaration, navigationKind: NavigationKind): GlobalSearchScope? {
+    private fun targetScopes(declaration: KtNamedDeclaration, navigationKind: NavigationKind): List<GlobalSearchScope> {
         val containingFile = declaration.containingKtFile
-        val vFile = containingFile.virtualFile ?: return null
+        val vFile = containingFile.virtualFile ?: return emptyList()
 
         return when (navigationKind) {
             NavigationKind.CLASS_FILES_TO_SOURCES -> {
                 val binaryModuleInfos = getBinaryLibrariesModuleInfos(declaration.project, vFile)
-                binaryModuleInfos.map { binaryModuleInfo ->
+                val primaryScope = binaryModuleInfos.mapNotNull { it.sourcesModuleInfo?.sourceScope() }.union()
-                    val platform = binaryModuleInfo.platform
+                val additionalScope = binaryModuleInfos.flatMap {
-                    if (platform == null || platform == TargetPlatform.Common) {
+                    it.associatedCommonLibraries()
-                        listOf(binaryModuleInfo)
+                }.mapNotNull { it.sourcesModuleInfo?.sourceScope() }.union()
-                    } else {
+                primaryScope + additionalScope
-                        binaryModuleInfo.dependencies().filterIsInstance<BinaryModuleInfo>().filter {
-                            it.platform == TargetPlatform.Common
-                        } + binaryModuleInfo
-                    }
-                }.flatten().mapNotNull { it.sourcesModuleInfo?.sourceScope() }.union()
             }
 
             NavigationKind.SOURCES_TO_CLASS_FILES -> getLibrarySourcesModuleInfos(
@@ -76,7 +72,17 @@ object SourceNavigationHelper {
         }
     }
 
-    private fun Collection<GlobalSearchScope>.union() = if (this.isNotEmpty()) GlobalSearchScope.union(this.toTypedArray()) else null
+    private fun BinaryModuleInfo.associatedCommonLibraries(): List<BinaryModuleInfo> {
+        val platform = platform
+        if (platform == null || platform == TargetPlatform.Common) return emptyList()
+
+        return dependencies().filterIsInstance<BinaryModuleInfo>().filter {
+            it.platform == TargetPlatform.Common
+        }
+    }
+
+    private fun Collection<GlobalSearchScope>.union(): List<GlobalSearchScope> =
+        if (this.isNotEmpty()) listOf(GlobalSearchScope.union(this.toTypedArray())) else emptyList()
 
     private fun haveRenamesInImports(files: Collection<KtFile>) = files.any { it.importDirectives.any { it.aliasName != null } }
 
@@ -183,8 +189,9 @@ object SourceNavigationHelper {
         index: StringStubIndexExtension<T>
     ): T? {
         val classFqName = entity.fqName ?: return null
-        val scope = targetScope(entity, navigationKind) ?: return null
+        return targetScopes(entity, navigationKind).firstNotNullResult {
-        return index.get(classFqName.asString(), entity.project, scope).firstOrNull()
+            index.get(classFqName.asString(), entity.project, it).firstOrNull()
+        }
     }
 
     private fun findClassOrObject(decompiledClassOrObject: KtClassOrObject, navigationKind: NavigationKind): KtClassOrObject? {
@@ -195,9 +202,13 @@ object SourceNavigationHelper {
         declaration: KtNamedDeclaration,
         navigationKind: NavigationKind
     ): Collection<KtNamedDeclaration> {
-        val scope = targetScope(declaration, navigationKind) ?: return emptyList()
+        val scopes = targetScopes(declaration, navigationKind)
         val index = getIndexForTopLevelPropertyOrFunction(declaration)
-        return index.get(declaration.fqName!!.asString(), declaration.project, scope)
+        for (scope in scopes) {
+            val candidates = index.get(declaration.fqName!!.asString(), declaration.project, scope)
+            if (candidates.isNotEmpty()) return candidates
+        }
+        return emptyList()
     }
 
     private fun getIndexForTopLevelPropertyOrFunction(