Include Platform.envrironment in pub, when passing custom environment option.

sdk/lib/_internal/pub/lib/src/io.dart

Index: sdk/lib/_internal/pub/lib/src/io.dart
diff --git a/sdk/lib/_internal/pub/lib/src/io.dart b/sdk/lib/_internal/pub/lib/src/io.dart
index f0f83c954bf804325d56259a2a6a098cf205f66a..659661fe547d274b4d09107d482377298227b53c 100644
--- a/sdk/lib/_internal/pub/lib/src/io.dart
+++ b/sdk/lib/_internal/pub/lib/src/io.dart
@@ -592,12 +592,19 @@ Future _doProcess(Function fn, String executable, List<String> args,
     executable = "cmd";
   }
 
+  var env = null;
+  if (environment != null) {
+    env = new Map.from(Platform.environment);
+    environment.forEach((key, value) => env[key] = value);

[nweiz, 2013/05/28 18:32:32]

Use mapAddAll from utils.dart.

+  }
+

[nweiz, 2013/05/28 18:32:32]

extra newline

+
   log.process(executable, args);
 
   return fn(executable,
             args,
             workingDirectory: workingDir,
-            environment: environment);
+            environment: env);
 }
 
 /// Wraps [input] to provide a timeout. If [input] completes before