Handle allow_stdin=false

Author: strangepleasures

src/main/kotlin/org/jetbrains/kotlin/jupyter/connection.kt

@@ -8,6 +8,7 @@ import org.jetbrains.kotlin.utils.addToStdlib.min
 import org.zeromq.SocketType
 import org.zeromq.ZMQ
 import java.io.Closeable
+import java.io.IOException
 import java.security.SignatureException
 import javax.crypto.Mac
 import javax.crypto.spec.SecretKeySpec
@@ -208,3 +209,9 @@ fun ZMQ.Socket.receiveMessage(start: ByteArray, hmac: HMAC): Message? {
         content.parseJson()
     )
 }
+
+object DisabledStdinInputStream : java.io.InputStream() {
+    override fun read(): Int {
+        throw IOException("Input from stdin is unsupported by the client")
+    }
+}

src/main/kotlin/org/jetbrains/kotlin/jupyter/protocol.kt

@@ -394,7 +394,8 @@ fun JupyterConnection.evalWithIO(config: OutputConfig, srcMessage: Message, body
     System.setErr(PrintStream(forkedError, false, "UTF-8"))
 
     val `in` = System.`in`
-    System.setIn(stdinIn)
+    val allowStdIn = srcMessage.content?.boolean("allow_stdin") ?: true
+    System.setIn(if (allowStdIn) stdinIn else DisabledStdinInputStream)
     try {
         return try {
             val exec = body()

src/test/kotlin/org/jetbrains/kotlin/jupyter/test/noStdinTests.kt

@@ -0,0 +1,64 @@
+package org.jetbrains.kotlin.jupyter.test
+
+import org.jetbrains.kotlin.jupyter.JupyterSockets
+import org.jetbrains.kotlin.jupyter.get
+import org.jetbrains.kotlin.jupyter.jsonObject
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.zeromq.ZMQ
+import kotlin.test.assertNotNull
+import kotlin.test.assertTrue
+
+class NoStdinTests : KernelServerTestsBase() {
+    fun execute(code: String) {
+        val context = ZMQ.context(1)
+        val shell = ClientSocket(context, JupyterSockets.shell)
+        val ioPub = ClientSocket(context, JupyterSockets.iopub)
+        val stdin = ClientSocket(context, JupyterSockets.stdin)
+        ioPub.subscribe(byteArrayOf())
+        try {
+            shell.connect()
+            ioPub.connect()
+            stdin.connect()
+
+            shell.sendMessage("execute_request",
+                    content = jsonObject("code" to code, "allow_stdin" to false))
+
+
+            var msg = shell.receiveMessage()
+            assertEquals("execute_reply", msg.type())
+            msg = ioPub.receiveMessage()
+            assertEquals("status", msg.type())
+            assertEquals("busy", msg.content["execution_state"])
+            msg = ioPub.receiveMessage()
+            assertEquals("execute_input", msg.type())
+
+            msg = ioPub.receiveMessage()
+            assertEquals("stream", msg.type())
+            assertEquals("stderr", msg.content["name"])
+            val text = msg.content?.string("text");
+            assertNotNull(text)
+            assertTrue(text.startsWith("java.io.IOException: Input from stdin is unsupported by the client"))
+
+            msg = ioPub.receiveMessage()
+            assertEquals("status", msg.type())
+            assertEquals("idle", msg.content["execution_state"])
+
+        } finally {
+            shell.close()
+            ioPub.close()
+            stdin.close()
+            context.term()
+        }
+    }
+
+    @Test
+    fun testReadLine() {
+        execute("readLine() ?: \"blah\"")
+    }
+
+    @Test
+    fun testStdinRead() {
+        execute("System.`in`.read()")
+    }
+}