add-remote-tarball: work around node 0.8 http back-pressure bug

0.8 http streams have a bug, where if they're paused with data in
their buffers when the socket closes, they call `end` before emptying
those buffers, which results in the entire pipeline ending and thus
the point that applied backpressure never being able to trigger a
`resume`.

We work around this by piping into a pass through stream that has
unlimited buffering. The pass through stream is from readable-stream
and is thus a current streams3 implementation that is free of these
bugs even on 0.8.

PR-URL: #10903
Credit: @iarna

Author: iarna

lib/cache/add-remote-tarball.js

@@ -5,6 +5,7 @@ var mkdir = require("mkdirp")
   , sha = require("sha")
   , retry = require("retry")
   , writeStreamAtomic = require("fs-write-stream-atomic")
+  , PassThrough = require('readable-stream').PassThrough
   , npm = require("../npm.js")
   , inflight = require("inflight")
   , addLocalTarball = require("./add-local-tarball.js")
@@ -105,6 +106,15 @@ function fetchAndShaCheck (u, tmp, shasum, auth, cb) {
       })
     })
 
-    response.pipe(tarball)
+    // 0.8 http streams have a bug, where if they're paused with data in
+    // their buffers when the socket closes, they call `end` before emptying
+    // those buffers, which results in the entire pipeline ending and thus
+    // the point that applied backpressure never being able to trigger a
+    // `resume`.
+    // We work around this by piping into a pass through stream that has
+    // unlimited buffering. The pass through stream is from readable-stream
+    // and is thus a current streams3 implementation that is free of these
+    // bugs even on 0.8.
+    response.pipe(PassThrough({highWaterMark: Infinity})).pipe(tarball)
   })
 }