Scripting: report error on duplicate import

#KT-48177 fixed
(due to the path normalization)

libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsTest.kt

@@ -121,6 +121,12 @@ class MainKtsTest {
         Assert.assertEquals(OUT_FROM_IMPORT_TEST, out)
     }
 
+    @Test
+    fun testDuplicateImportError() {
+        val res = evalFile(File("$TEST_DATA_ROOT/import-duplicate-test.main.kts"))
+        assertFailed("Duplicate imports:", res)
+    }
+
     @Test
     fun testCompilerOptions() {
 

libraries/tools/kotlin-main-kts-test/testData/import-duplicate-test.main.kts

@@ -0,0 +1,5 @@
+
+@file:Import("import-common.main.kts")
+@file:Import("../testData/import-common.main.kts")
+
+sharedVar = sharedVar + 1

libraries/tools/kotlin-main-kts/src/org/jetbrains/kotlin/mainKts/scriptDef.kt

@@ -125,11 +125,26 @@ class MainKtsConfigurator : RefineScriptCompilationConfigurationHandler {
             ?: return context.compilationConfiguration.asSuccess()
 
         val scriptBaseDir = (context.script as? FileBasedScriptSource)?.file?.parentFile
-        val importedSources = annotations.filterByAnnotationType<Import>().flatMap {
-            it.annotation.paths.map { sourceName ->
-                FileScriptSource(scriptBaseDir?.resolve(sourceName) ?: File(sourceName))
+        val importedSources = linkedMapOf<String, Pair<File, String>>()
+        var hasImportErrors = false
+        annotations.filterByAnnotationType<Import>().forEach { scriptAnnotation ->
+            scriptAnnotation.annotation.paths.forEach { sourceName ->
+                val file = (scriptBaseDir?.resolve(sourceName) ?: File(sourceName)).normalize()
+                val keyPath = file.absolutePath
+                val prevImport = importedSources.put(keyPath, file to sourceName)
+                if (prevImport != null) {
+                    diagnostics.add(
+                        ScriptDiagnostic(
+                            ScriptDiagnostic.unspecifiedError, "Duplicate imports: \"${prevImport.second}\" and \"$sourceName\"",
+                            sourcePath = context.script.locationId, location = scriptAnnotation.location?.locationInText
+                        )
+                    )
+                    hasImportErrors = true
+                }
             }
         }
+        if (hasImportErrors) return ResultWithDiagnostics.Failure(diagnostics)
+
         val compileOptions = annotations.filterByAnnotationType<CompilerOptions>().flatMap {
             it.annotation.options.toList()
         }
@@ -140,13 +155,14 @@ class MainKtsConfigurator : RefineScriptCompilationConfigurationHandler {
                 resolver.resolveFromScriptSourceAnnotations(annotations.filter { it.annotation is DependsOn || it.annotation is Repository })
             }
         } catch (e: Throwable) {
-            ResultWithDiagnostics.Failure(*diagnostics.toTypedArray(), e.asDiagnostics(path = context.script.locationId))
+            diagnostics.add(e.asDiagnostics(path = context.script.locationId))
+            ResultWithDiagnostics.Failure(diagnostics)
         }
 
         return resolveResult.onSuccess { resolvedClassPath ->
             ScriptCompilationConfiguration(context.compilationConfiguration) {
                 updateClasspath(resolvedClassPath)
-                if (importedSources.isNotEmpty()) importScripts.append(importedSources)
+                if (importedSources.isNotEmpty()) importScripts.append(importedSources.values.map { FileScriptSource(it.first) })
                 if (compileOptions.isNotEmpty()) compilerOptions.append(compileOptions)
             }.asSuccess()
         }