If there are errors from multiple files, the errors from the currently editing file should be visible in error list first. Further, if the cursor is on a line with an error, the corresponding ErrorList node should be selected and visible. action "Next Error" should go to the next error after that, instead of the first error on the top of the tree.
Perhaps just moving the current file to the top of the error tree will be the easiest way to get this working.
Also, if the user clicks on the error icon in the gutter, it should tell ErrorList to show that node in the tree.
This is important when there are lots of errors in lots of different files and the user wants to focus on the errors in the current file.
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