Fix source mapping for stepping into package facades from libraries (KT-28028)

idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/DebuggerUtils.kt

@@ -75,41 +75,27 @@ object DebuggerUtils {
         if (!isKotlinSourceFile(fileName)) return null
         if (DumbService.getInstance(project).isDumb) return null
 
-        val filesWithExactName = scopes.findFirstNotEmpty { findFilesByNameInPackage(className, fileName, project, it) } ?: return null
-
-        if (filesWithExactName.isEmpty()) return null
-
-        if (filesWithExactName.size == 1 && !forceRanking) {
-            return filesWithExactName.single()
-        }
-
-        // Static facade or inner class of such facade?
         val partFqName = className.fqNameForClassNameWithoutDollars
-        val filesForPart = scopes.findFirstNotEmpty { StaticFacadeIndexUtil.findFilesForFilePart(partFqName, it, project) } ?: return null
-        if (!filesForPart.isEmpty()) {
-            for (file in filesForPart) {
-                if (file.name == fileName) {
-                    return file
-                }
+
+        for (scope in scopes) {
+            val files = findFilesByNameInPackage(className, fileName, project, scope)
+
+            if (files.isEmpty()) {
+                continue
             }
-            // Do not fall back to decompiled files (which have different name).
-            return null
+
+            if (files.size == 1 && !forceRanking || location == null) {
+                return files.first()
+            }
+
+            StaticFacadeIndexUtil.findFilesForFilePart(partFqName, scope, project)
+                .singleOrNull { it.name == fileName }
+                ?.let { return it }
+
+            return FileRankingCalculatorForIde.findMostAppropriateSource(files, location)
         }
 
-        if (location != null) {
-            return FileRankingCalculatorForIde.findMostAppropriateSource(filesWithExactName, location)
-        }
-
-        return filesWithExactName.first()
-    }
-
-    private fun <T, R> Collection<T>.findFirstNotEmpty(predicate: (T) -> Collection<R>): Collection<R>? {
-        var result: Collection<R> = emptyList()
-        for (e in this) {
-            result = predicate(e)
-            if (result.isNotEmpty()) break
-        }
-        return result
+        return null
     }
 
     private fun findFilesByNameInPackage(

idea/testData/debugger/tinyApp/src/stepping/stepInto/sameFileNames.kt

@@ -0,0 +1,8 @@
+package sameFileNames
+
+fun main() {
+    //Breakpoint!
+    val result = simple.foo()
+}
+
+// STEP_INTO: 1

idea/testData/debugger/tinyApp/src/stepping/stepInto/sameFileNames.out

@@ -0,0 +1,8 @@
+LineBreakpoint created at sameFileNames.kt:5
+Run Java
+Connected to the target VM
+sameFileNames.kt:5
+simpleKt.kt:5
+Disconnected from the target VM
+
+Process finished with exit code 0

idea/tests/org/jetbrains/kotlin/idea/debugger/KotlinSteppingTestGenerated.java

@@ -272,6 +272,11 @@ public class KotlinSteppingTestGenerated extends AbstractKotlinSteppingTest {
             runTest("idea/testData/debugger/tinyApp/src/stepping/stepInto/samAdapter.kt");
         }
 
+        @TestMetadata("sameFileNames.kt")
+        public void testSameFileNames() throws Exception {
+            runTest("idea/testData/debugger/tinyApp/src/stepping/stepInto/sameFileNames.kt");
+        }
+
         @TestMetadata("siSuspendFun.kt")
         public void testSiSuspendFun() throws Exception {
             runTest("idea/testData/debugger/tinyApp/src/stepping/stepInto/siSuspendFun.kt");