pipeInputToInput should be resilient to stream closure.

utils/pub/io.dart

Index: utils/pub/io.dart
diff --git a/utils/pub/io.dart b/utils/pub/io.dart
index 0c30c885dbb85046ad2d7999ee172b869224e213..dc779f5595d632b726d341670f78a81a4a9bd2eb 100644
--- a/utils/pub/io.dart
+++ b/utils/pub/io.dart
@@ -619,7 +619,9 @@ Future pipeInputToInput(InputStream source, ListInputStream sink) {
     sink.markEndOfStream();
     completer.complete(null);
   };
-  source.onData = () => sink.write(source.read());
+  source.onData = () {
+    if (!sink.closed) sink.write(source.read());

[Bob Nystrom, 2012/12/08 03:35:33]

Should do the read() even if it's closed.

Also, maybe log this? Is it unexpected for this to happen?

[nweiz, 2012/12/08 03:38:04]

I think it's more or less "business as usual" for streams. Probably not worth
logging, as it's very hard to know what the context is and may provide a high
volume of low-utility information.

+  };
   // TODO(nweiz): propagate this error to the sink. See issue 3657.
   source.onError = (e) { throw e; };
   return completer.future;