stream: fix deadlock when pipeing to full sink

When piping a paused Readable to a full Writable we didn't
register a drain listener which cause the src to never
resume.

Refs: #48666

Author: ronag

lib/internal/streams/readable.js

@@ -756,8 +756,12 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
         debug('false write response, pause', state.awaitDrainWriters.size);
         state.awaitDrainWriters.add(dest);
       }
+
       src.pause();
     }
+  }
+
+  function registerDrain () {
     if (!ondrain) {
       // When the dest drains, it reduces the awaitDrain counter
       // on the source.  This would be more elegant with a .once()
@@ -775,6 +779,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
     debug('dest.write', ret);
     if (ret === false) {
       pause();
+      registerDrain();
     }
   }
 
@@ -825,6 +830,7 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
     if (state.flowing) {
       pause();
     }
+    registerDrain();
   } else if (!state.flowing) {
     debug('pipe resume');
     src.resume();

test/parallel/test-stream-pipe-deadlock.js

@@ -0,0 +1,27 @@
+"use strict";
+
+const common = require('../common');
+const { Readable, Writable } = require('stream');
+
+// https://github.com/nodejs/node/issues/48666
+(async () => {
+  // Prepare src that is internally ended, with buffered data pending
+  const src = new Readable({ read() {} });
+  src.push(Buffer.alloc(100));
+  src.push(null);
+  src.pause();
+
+  // Give it time to settle
+  await new Promise((resolve) => setImmediate(resolve));
+
+  const dst = new Writable({
+    highWaterMark: 1000,
+    write(buf, enc, cb) {
+      process.nextTick(cb);
+    }
+  });
+
+  dst.write(Buffer.alloc(1000)); // Fill write buffer
+  dst.on('finish', common.mustCall());
+  src.pipe(dst);
+})();