This PR is a rewrite of the "s:UI.getLineNum()" function. This change
improves the logic and clarity of this function, and it fixes the function's
ability to work with cascades.
Fixes#529.
This change puts the burden on the user to make sure
g:NERDTreeBookmarksFile is correctly set and the path it contains is
present and has the proper permissions. If this is not the case, an
error message is displayed. This is a better solution than to blindly
create the path, when it may actually be impossible to do so.
When the user has `'autochdir'` turned on, opening a new NERDTree will
cause the current working directory to change. To prevent this
happening, remember the CWD and reset it if NERDTreeFocus caused it to
change.
When NERTDtree opens a file, it compares this new file to all open
buffers to see if it's already open. If the user has 'ignorecase' turned
on then the comparison of "file" and "File" says they're the same, and
NERDTree won't reopen the file. This commit forces a case sensitive
comparison by using the ==# operator.
If the cursor is not already positioned on a node when the bookmark
table is closed, then the resulting position of the cursor is not
determined. Here, we default to positioning the cursor on the
root when the bookmark table is closed.
Also add a new global variable to track when the g:NERDTreeSortOrder
changes. If it has been changed, or when the cached _sortKey value is
uninitialized, then calculate the sort key. This improves processing
speed over the previous commit, and allows on-the-fly changes to the
sort order, (without required vim to be restarted.)
The call to AddDefaultGroupToSortOrder in NERD_tree.vim is redundant
because it's also done every time sortChildren is called. And since the
check is done only once, there's no need for a function either.
sortChildren now just contains the needed if statement.
This commit makes adding, removing and finding key maps an O(1)
operation instead of O(n), where n is the number of pre-existing maps.
In my testing, averaged over 100 iterations, this reduces the time spent
initializing NERDTree at Vim startup from ~73ms to ~9.7ms. That's with
only the default included key maps.
Using the ":clearjumps" command wipes out the jump list for the
current window. This means that the user can't inadvertently jump
out of the NERDTree buffer while using the NERDTree window (i.e., by
using "<C-O>").
