Increment repl line generation on compilation error

fixes #KT-17921 and #KT-21141
Tests added to the JSR223 local eval example

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/BasicReplState.kt

@@ -53,6 +53,7 @@ open class BasicReplStageHistory<T>(override val lock: ReentrantReadWriteLock =
         lock.write {
             val removed = map { it.id }
             clear()
+            currentGeneration.incrementAndGet()
             return removed
         }
     }
@@ -67,7 +68,10 @@ open class BasicReplStageHistory<T>(override val lock: ReentrantReadWriteLock =
                 currentGeneration.incrementAndGet()
                 removed
             }
-            else emptyList()
+            else {
+                currentGeneration.incrementAndGet()
+                emptyList()
+            }
         }
     }
 }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/GenericReplCompilingEvaluator.kt

@@ -35,7 +35,15 @@ class GenericReplCompilingEvaluator(val compiler: ReplCompiler,
             val aggregatedState = state.asState(AggregatedReplStageState::class.java)
             val compiled = compiler.compile(state, codeLine)
             when (compiled) {
-                is ReplCompileResult.Error -> ReplEvalResult.Error.CompileTime(compiled.message, compiled.location)
+                is ReplCompileResult.Error -> {
+                    aggregatedState.apply {
+                        lock.write {
+                            assert(state1.history.size == state2.history.size)
+                            adjustHistories() // needed due to statefulness of AnalyzerEngine - in case of compilation errors the line name reuse leads to #KT-17921
+                        }
+                    }
+                    ReplEvalResult.Error.CompileTime(compiled.message, compiled.location)
+                }
                 is ReplCompileResult.Incomplete -> ReplEvalResult.Incomplete()
                 is ReplCompileResult.CompiledClasses -> {
                     val result = eval(state, compiled, scriptArgs, invokeWrapper)
@@ -46,14 +54,7 @@ class GenericReplCompilingEvaluator(val compiler: ReplCompiler,
                             aggregatedState.apply {
                                 lock.write {
                                     if (state1.history.size > state2.history.size) {
-                                        if (state2.history.size == 0) {
-                                            state1.history.reset()
-                                        }
-                                        else {
-                                            state2.history.peek()?.let {
-                                                state1.history.resetTo(it.id)
-                                            }
-                                        }
+                                        adjustHistories()
                                         assert(state1.history.size == state2.history.size)
                                     }
                                 }
@@ -91,3 +92,9 @@ class GenericReplCompilingEvaluator(val compiler: ReplCompiler,
                 evaluator.eval(state, compiledCode, scriptArgs ?: defaultScriptArgs, invokeWrapper)
     }
 }
+
+private fun AggregatedReplStageState<*, *>.adjustHistories(): Iterable<ILineId>? =
+        state2.history.peek()?.let {
+            state1.history.resetTo(it.id)
+        }
+        ?: state1.history.reset()

libraries/examples/kotlin-jsr223-local-example/src/test/kotlin/org/jetbrains/kotlin/script/jsr223/KotlinJsr223ScriptEngineIT.kt

@@ -72,6 +72,46 @@ class KotlinJsr223LocalScriptEngineIT {
         Assert.assertEquals(5, res2)
     }
 
+    @Test
+    fun testEvalWithError() {
+        val engine = ScriptEngineManager().getEngineByExtension("kts")!!
+
+        try {
+            engine.eval("java.lang.fish")
+            Assert.fail("Script error expected")
+        }
+        catch (e: ScriptException) {}
+
+        val res1 = engine.eval("val x = 3")
+        Assert.assertNull(res1)
+
+        try {
+            engine.eval("y")
+            Assert.fail("Script error expected")
+        }
+        catch (e: ScriptException) {
+            Assert.assertTrue("Expected message to contain \"unresolved reference: y\", actual: \"${e.message}\"",
+                              e.message?.contains("unresolved reference: y") ?: false)
+        }
+
+        val res3 = engine.eval("x + 2")
+        Assert.assertEquals(5, res3)
+    }
+
+    @Test
+    fun testEngineRepeatWithReset() {
+        val code = "open class A {}\n" +
+                   "class B : A() {}"
+        val engine = ScriptEngineManager().getEngineByExtension("kts") as KotlinJsr223JvmLocalScriptEngine
+
+        val res1 = engine.eval(code)
+        Assert.assertNull(res1)
+
+        engine.state.history.reset()
+
+        engine.eval(code)
+    }
+
     @Test
     fun testInvocable() {
         val engine = ScriptEngineManager().getEngineByExtension("kts")!!