Scripting: notify writer in REPL on errors reporting complete

required for restoring compatibility with IDE REPL usages (scratch
files included), since IDE counterpart needs a reliable signal
when the processing of the REPL snippet/command is completed

compiler/util/src/org/jetbrains/kotlin/utils/repl/ReplEscapeType.kt

@@ -27,6 +27,8 @@ enum class ReplEscapeType {
     COMPILE_ERROR,
     RUNTIME_ERROR,
     INTERNAL_ERROR,
+    ERRORS_REPORTED, // should be send after reporting all errors caused by the current command
+                     // e.g. IDE uses it to recognize the end of command processing
     SUCCESS;
 
     companion object {

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/repl/ReplFromTerminal.kt

@@ -139,10 +139,19 @@ class ReplFromTerminal(
                     writer.outputCommandResult(tryInterpretResultAsValueClass(evalResult) ?: evalResult.toString())
                 }
             }
-            is ReplEvalResult.Error.Runtime -> if (evalResult.message.isNotEmpty()) writer.outputRuntimeError(evalResult.message)
-            is ReplEvalResult.Error.CompileTime -> if (evalResult.message.isNotEmpty()) writer.outputCompileError(evalResult.message)
+            is ReplEvalResult.Error.Runtime -> {
+                if (evalResult.message.isNotEmpty()) writer.outputRuntimeError(evalResult.message)
+                writer.notifyErrorsReported()
+            }
+            is ReplEvalResult.Error.CompileTime -> {
+                if (evalResult.message.isNotEmpty()) writer.outputCompileError(evalResult.message)
+                writer.notifyErrorsReported()
+            }
             is ReplEvalResult.Incomplete -> writer.notifyIncomplete()
-            is ReplEvalResult.HistoryMismatch -> {} // assuming handled elsewhere
+            is ReplEvalResult.HistoryMismatch -> {
+                // assuming that internal error reported elsewhere
+                writer.notifyErrorsReported()
+            }
         }
         return evalResult
     }

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/repl/writer/ConsoleReplWriter.kt

@@ -17,4 +17,5 @@ class ConsoleReplWriter : ReplWriter {
     override fun notifyIncomplete() {}
     override fun notifyCommandSuccess() {}
     override fun sendInternalErrorReport(x: String) {}
+    override fun notifyErrorsReported() {}
 }

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/repl/writer/IdeSystemOutWrapperReplWriter.kt

@@ -40,4 +40,5 @@ class IdeSystemOutWrapperReplWriter(standardOut: PrintStream) : PrintStream(stan
     override fun outputCompileError(x: String) = printlnWithEscaping(x, COMPILE_ERROR)
     override fun outputRuntimeError(x: String) = printlnWithEscaping(x, RUNTIME_ERROR)
     override fun sendInternalErrorReport(x: String) = printlnWithEscaping(x, INTERNAL_ERROR)
+    override fun notifyErrorsReported() = printlnWithEscaping("", ERRORS_REPORTED)
 }

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/repl/writer/ReplWriter.kt

@@ -16,4 +16,5 @@ interface ReplWriter {
     fun outputCompileError(x: String)
     fun outputRuntimeError(x: String)
     fun sendInternalErrorReport(x: String)
+    fun notifyErrorsReported()
 }