scrooloose/nerdtree — pull request #96 by mkomitee (2011-11-11 16:44:46+00:00)
Title: Allows an option to reuse existing windows

If a user so chooses by toggling an option, when he tries to open a file from the nerd tree either directly (double-click, , o, go) or in a split (i, s), if he already has that buffer viewable in a window, instead of changing the current window to also have that file open, or opening a new split to view that buffer, it will switch focus to the existing window.

The option is named NERDTreeUseExistingWindows, and it defaults to 0 to not change the default behavior of the plugin.