{"action":"created","issue":{"url":"https://api.github.com/repos/dotnet/roslyn/issues/1117","labels_url":"https://api.github.com/repos/dotnet/roslyn/issues/1117/labels{/name}","comments_url":"https://api.github.com/repos/dotnet/roslyn/issues/1117/comments","events_url":"https://api.github.com/repos/dotnet/roslyn/issues/1117/events","html_url":"https://github.com/dotnet/roslyn/pull/1117","id":60191965,"number":1117,"title":"Disable Array.Empty params array optimization in expression lambdas","user":{"login":"stephentoub","id":2642209,"avatar_url":"https://avatars.githubusercontent.com/u/2642209?v=3","gravatar_id":"","url":"https://api.github.com/users/stephentoub","html_url":"https://github.com/stephentoub","followers_url":"https://api.github.com/users/stephentoub/followers","following_url":"https://api.github.com/users/stephentoub/following{/other_user}","gists_url":"https://api.github.com/users/stephentoub/gists{/gist_id}","starred_url":"https://api.github.com/users/stephentoub/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/stephentoub/subscriptions","organizations_url":"https://api.github.com/users/stephentoub/orgs","repos_url":"https://api.github.com/users/stephentoub/repos","events_url":"https://api.github.com/users/stephentoub/events{/privacy}","received_events_url":"https://api.github.com/users/stephentoub/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/dotnet/roslyn/labels/cla-not-required","name":"cla-not-required","color":"90EE90"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-03-07T05:33:55Z","updated_at":"2015-03-08T05:18:21Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/dotnet/roslyn/pulls/1117","html_url":"https://github.com/dotnet/roslyn/pull/1117","diff_url":"https://github.com/dotnet/roslyn/pull/1117.diff","patch_url":"https://github.com/dotnet/roslyn/pull/1117.patch"},"body":"Fixes #1103.  Or more specifically, #1103 represents two issues: that we do the Array.Empty optimization for params arrays in the expression lambda, and that this optimization does not kick in when compiling expression lambdas... this fix addresses the former but not the latter.\r\n\r\nThe actual fix is a one-line trivial change.  In terms of tests, there's actually already a test for this case, but as it compiles against an earlier mscorlib that lacks Array.Empty, it passes even before the fix.  I augmented the test to also try to run it on a newer mscorlib, but since the Roslyn test suite doesn't yet contain the metadata for mscorlib 4.6, I use the mscorlib on which the test is running as a substitute (thanks to @jaredpar for the suggestion); worst case is the test isn't running on 4.6 and it passes but doesn't verify what we wanted it to.  I did verify that on 4.6 the test fails before the product fix and passes after it."},"comment":{"url":"https://api.github.com/repos/dotnet/roslyn/issues/comments/77733855","html_url":"https://github.com/dotnet/roslyn/pull/1117#issuecomment-77733855","issue_url":"https://api.github.com/repos/dotnet/roslyn/issues/1117","id":77733855,"user":{"login":"pharring","id":9952654,"avatar_url":"https://avatars.githubusercontent.com/u/9952654?v=3","gravatar_id":"","url":"https://api.github.com/users/pharring","html_url":"https://github.com/pharring","followers_url":"https://api.github.com/users/pharring/followers","following_url":"https://api.github.com/users/pharring/following{/other_user}","gists_url":"https://api.github.com/users/pharring/gists{/gist_id}","starred_url":"https://api.github.com/users/pharring/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pharring/subscriptions","organizations_url":"https://api.github.com/users/pharring/orgs","repos_url":"https://api.github.com/users/pharring/repos","events_url":"https://api.github.com/users/pharring/events{/privacy}","received_events_url":"https://api.github.com/users/pharring/received_events","type":"User","site_admin":false},"created_at":"2015-03-08T05:18:21Z","updated_at":"2015-03-08T05:18:21Z","body":"LGTM"}}