If an empty context is passed it would appear in the compacted document as the context is copied 1:1. To not pass a context, the context document should not contain a @context property.
test-suite/tests/compact-0001-context.jsonld
test-suite/tests/compact-0003-context.jsonld
--- a/test-suite/tests/compact-0001-context.jsonld Sun May 20 22:42:52 2012 -0400+++ b/test-suite/tests/compact-0001-context.jsonld Mon May 21 21:45:28 2012 +0800@@ -1,3 +1,2 @@ {- "@context": {}-}\ No newline at end of file+}
--- a/test-suite/tests/compact-0003-context.jsonld Sun May 20 22:42:52 2012 -0400+++ b/test-suite/tests/compact-0003-context.jsonld Mon May 21 21:45:28 2012 +0800@@ -1,3 +1,2 @@ {- "@context": {}-}\ No newline at end of file+}