Merge pull request #795 from lifecrisis/empty-line

Fix unstable behaviour in the "NERDTreeUI.getPath()" method.

lib/nerdtree/path.vim

@@ -14,21 +14,23 @@ lockvar s:NERDTreeSortStarIndex
 let s:Path = {}
 let g:NERDTreePath = s:Path
 
-" FUNCTION: Path.AbsolutePathFor(str) {{{1
-function! s:Path.AbsolutePathFor(str)
-    let prependCWD = 0
+" FUNCTION: Path.AbsolutePathFor(pathStr) {{{1
+function! s:Path.AbsolutePathFor(pathStr)
+    let l:prependWorkingDir = 0
+
     if nerdtree#runningWindows()
-        let prependCWD = a:str !~# '^.:\(\\\|\/\)' && a:str !~# '^\(\\\\\|\/\/\)'
+        let l:prependWorkingDir = a:pathStr !~# '^.:\(\\\|\/\)' && a:pathStr !~# '^\(\\\\\|\/\/\)'
     else
-        let prependCWD = a:str !~# '^/'
+        let l:prependWorkingDir = a:pathStr !~# '^/'
     endif
 
-    let toReturn = a:str
-    if prependCWD
-        let toReturn = getcwd() . s:Path.Slash() . a:str
+    let l:result = a:pathStr
+
+    if l:prependWorkingDir
+        let l:result = getcwd() . s:Path.Slash() . a:pathStr
     endif
 
-    return toReturn
+    return l:result
 endfunction
 
 " FUNCTION: Path.bookmarkNames() {{{1
@@ -541,17 +543,16 @@ function! s:Path.equals(path)
     return self.str() ==# a:path.str()
 endfunction
 
-" FUNCTION: Path.New() {{{1
-" The Constructor for the Path object
-function! s:Path.New(path)
-    let newPath = copy(self)
+" FUNCTION: Path.New(pathStr) {{{1
+function! s:Path.New(pathStr)
+    let l:newPath = copy(self)
 
-    call newPath.readInfoFromDisk(s:Path.AbsolutePathFor(a:path))
+    call l:newPath.readInfoFromDisk(s:Path.AbsolutePathFor(a:pathStr))
 
-    let newPath.cachedDisplayString = ""
-    let newPath.flagSet = g:NERDTreeFlagSet.New()
+    let l:newPath.cachedDisplayString = ''
+    let l:newPath.flagSet = g:NERDTreeFlagSet.New()
 
-    return newPath
+    return l:newPath
 endfunction
 
 " FUNCTION: Path.Slash() {{{1

lib/nerdtree/tree_file_node.vim

@@ -1,8 +1,11 @@
+" ============================================================================
 " CLASS: TreeFileNode
-"This class is the parent of the TreeDirNode class and is the
-"'Component' part of the composite design pattern between the treenode
-"classes.
-"============================================================
+"
+" This class is the parent of the "TreeDirNode" class and is the "Component"
+" part of the composite design pattern between the NERDTree node classes.
+" ============================================================================
+
+
 let s:TreeFileNode = {}
 let g:NERDTreeFileNode = s:TreeFileNode
 
@@ -193,14 +196,18 @@ function! s:TreeFileNode.GetRootForTab()
 endfunction
 
 " FUNCTION: TreeFileNode.GetSelected() {{{1
-"gets the treenode that the cursor is currently over
+" If the cursor is currently positioned on a tree node, return the node.
+" Otherwise, return the empty dictionary.
 function! s:TreeFileNode.GetSelected()
+
     try
-        let path = b:NERDTree.ui.getPath(line("."))
-        if path ==# {}
+        let l:path = b:NERDTree.ui.getPath(line('.'))
+
+        if empty(l:path)
             return {}
         endif
-        return b:NERDTree.root.findNode(path)
+
+        return b:NERDTree.root.findNode(l:path)
     catch /^NERDTree/
         return {}
     endtry

lib/nerdtree/ui.vim

@@ -1,5 +1,8 @@
+" ============================================================================
 " CLASS: UI
-"============================================================
+" ============================================================================
+
+
 let s:UI = {}
 let g:NERDTreeUI = s:UI
 
@@ -138,21 +141,15 @@ function! s:UI.New(nerdtree)
 endfunction
 
 " FUNCTION: s:UI.getPath(ln) {{{1
-"Gets the full path to the node that is rendered on the given line number
-"
-"Args:
-"ln: the line number to get the path for
-"
-"Return:
-"A path if a node was selected, {} if nothing is selected.
-"If the 'up a dir' line was selected then the path to the parent of the
-"current root is returned
+" Return the "Path" object for the node that is rendered on the given line
+" number.  If the "up a dir" line is selected, return the "Path" object for
+" the parent of the root.  Return the empty dictionary if the given line
+" does not reference a tree node.
 function! s:UI.getPath(ln)
     let line = getline(a:ln)
 
     let rootLine = self.getRootLineNum()
 
-    "check to see if we have the root node
     if a:ln == rootLine
         return self.nerdtree.root.path
     endif
@@ -161,6 +158,10 @@ function! s:UI.getPath(ln)
         return self.nerdtree.root.path.getParent()
     endif
 
+    if a:ln < rootLine
+        return {}
+    endif
+
     let indent = self._indentLevelFor(line)
 
     " remove the tree parts and the leading space