{"action":"created","issue":{"url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/10","labels_url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/10/labels{/name}","comments_url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/10/comments","events_url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/10/events","html_url":"https://github.com/NetTopologySuite/ProjNet4GeoAPI/issues/10","id":115040137,"number":10,"title":"ConcatenatedTransform.Inverse() method destroys the state of child transformations","user":{"login":"Nipheris","id":3228619,"avatar_url":"https://avatars.githubusercontent.com/u/3228619?v=3","gravatar_id":"","url":"https://api.github.com/users/Nipheris","html_url":"https://github.com/Nipheris","followers_url":"https://api.github.com/users/Nipheris/followers","following_url":"https://api.github.com/users/Nipheris/following{/other_user}","gists_url":"https://api.github.com/users/Nipheris/gists{/gist_id}","starred_url":"https://api.github.com/users/Nipheris/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Nipheris/subscriptions","organizations_url":"https://api.github.com/users/Nipheris/orgs","repos_url":"https://api.github.com/users/Nipheris/repos","events_url":"https://api.github.com/users/Nipheris/events{/privacy}","received_events_url":"https://api.github.com/users/Nipheris/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/labels/help%20wanted","name":"help wanted","color":"159818"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2015-11-04T12:15:23Z","updated_at":"2015-11-04T15:51:22Z","closed_at":null,"body":"The bug is related to [ConcatenatedTransform.Inverse()](https://github.com/NetTopologySuite/ProjNet4GeoAPI/blob/master/ProjNet/CoordinateSystems/Transformations/ConcatenatedTransform.cs#L129) method, which has unexpected side effects on child transformations in the list. Because of the absense of deep cloning of child transformations in [Clone()](https://github.com/NetTopologySuite/ProjNet4GeoAPI/blob/master/ProjNet/CoordinateSystems/Transformations/ConcatenatedTransform.cs#L149), the call of [Invert()](https://github.com/NetTopologySuite/ProjNet4GeoAPI/blob/master/ProjNet/CoordinateSystems/Transformations/ConcatenatedTransform.cs#L134) method on the cloned ConcatenatedTransform object leads to subsequent calls of Invert() on the original child transformations.\r\n\r\nTo fix this I suggest to reimplement ConcatenatedTransform.Inverse() method to make him create the new ConcatenatedTransform object from the subsequent calls of Inverse() on child transforms (not Invert())."},"comment":{"url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/comments/153770738","html_url":"https://github.com/NetTopologySuite/ProjNet4GeoAPI/issues/10#issuecomment-153770738","issue_url":"https://api.github.com/repos/NetTopologySuite/ProjNet4GeoAPI/issues/10","id":153770738,"user":{"login":"Nipheris","id":3228619,"avatar_url":"https://avatars.githubusercontent.com/u/3228619?v=3","gravatar_id":"","url":"https://api.github.com/users/Nipheris","html_url":"https://github.com/Nipheris","followers_url":"https://api.github.com/users/Nipheris/followers","following_url":"https://api.github.com/users/Nipheris/following{/other_user}","gists_url":"https://api.github.com/users/Nipheris/gists{/gist_id}","starred_url":"https://api.github.com/users/Nipheris/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Nipheris/subscriptions","organizations_url":"https://api.github.com/users/Nipheris/orgs","repos_url":"https://api.github.com/users/Nipheris/repos","events_url":"https://api.github.com/users/Nipheris/events{/privacy}","received_events_url":"https://api.github.com/users/Nipheris/received_events","type":"User","site_admin":false},"created_at":"2015-11-04T15:51:22Z","updated_at":"2015-11-04T15:51:22Z","body":"Sure, I will fork the repo a bit later, and will provide fix and testcase."}}