Use :undolist for older Vim versions

autoload/ctrlp.vim

@@ -735,7 +735,7 @@ fu! s:SetWD(...)
 		cal extend(markers, s:rmarkers, 0)
 	en
 	for marker in markers
-		cal s:findroot(getcwd(), marker, 0, 0)
+		cal s:findroot(s:dyncwd, marker, 0, 0)
 		if exists('s:foundroot') | brea | en
 	endfo
 	unl! s:foundroot
@@ -1413,9 +1413,8 @@ fu! s:getenv()
 	let s:wpmode = exists('b:ctrlp_working_path_mode')
 		\ ? b:ctrlp_working_path_mode : s:pathmode
 	if exists('g:ctrlp_extensions')
-		if index(g:ctrlp_extensions, 'undo') >= 0 && exists('*undotree')
-			\ && ( v:version > 703 || ( v:version == 703 && has('patch005') ) )
-			let s:undotree = undotree()
+		if index(g:ctrlp_extensions, 'undo') >= 0
+			let s:undos = s:getundo()
 		en
 		if index(g:ctrlp_extensions, 'tag') >= 0
 			let s:tagfiles = s:tagfiles()
@@ -1541,6 +1540,18 @@ fu! s:extvar(key)
 	en
 endf
 
+fu! s:getundo()
+	if exists('*undotree')
+		\ && ( v:version > 703 || ( v:version == 703 && has('patch005') ) )
+		retu [1, undotree()]
+	el
+		redi => result
+		sil! undol
+		redi END
+		retu [0, split(result, "\n")[1:]]
+	en
+endf
+
 fu! ctrlp#exit()
 	cal s:PrtExit()
 endf

autoload/ctrlp/undo.vim

@@ -6,16 +6,16 @@
 
 " Init {{{1
 if ( exists('g:loaded_ctrlp_undo') && g:loaded_ctrlp_undo )
-	\ || !( v:version > 703 || ( v:version == 703 && has('patch005') ) )
 	fini
 en
 let g:loaded_ctrlp_undo = 1
 
 let s:undo_var = {
-	\ 'init': 'ctrlp#undo#init(s:undotree)',
+	\ 'init': 'ctrlp#undo#init(s:undos)',
 	\ 'accept': 'ctrlp#undo#accept',
 	\ 'lname': 'undo',
 	\ 'sname': 'udo',
+	\ 'exit': 'ctrlp#undo#exit()',
 	\ 'type': 'line',
 	\ }
 
@@ -23,6 +23,9 @@ let g:ctrlp_ext_vars = exists('g:ctrlp_ext_vars') && !empty(g:ctrlp_ext_vars)
 	\ ? add(g:ctrlp_ext_vars, s:undo_var) : [s:undo_var]
 
 let s:id = g:ctrlp_builtins + len(g:ctrlp_ext_vars)
+
+let s:text = map(['second', 'seconds', 'minutes', 'hours', 'days', 'weeks',
+	\ 'months', 'years'], '" ".v:val." ago"')
 " Utilities {{{1
 fu! s:flatten(tree, cur)
 	let flatdict = {}
@@ -37,24 +40,14 @@ fu! s:flatten(tree, cur)
 	retu flatdict
 endf
 
-fu! s:humantime(nr)
-	let elapsed = localtime() - a:nr
-	let mins = elapsed / 60
-	let hrs  = elapsed / 3600
-	let days = elapsed / 86400
-	let wks  = elapsed / 604800
-	let mons = elapsed / 2592000
-	let yrs  = elapsed / 31536000
-	let text = [
-		\ ' second ago',
-		\ ' seconds ago',
-		\ ' minutes ago',
-		\ ' hours ago',
-		\ ' days ago',
-		\ ' weeks ago',
-		\ ' months ago',
-		\ ' years ago',
-		\ ]
+fu! s:elapsed(nr)
+	let [text, time] = [s:text, localtime() - a:nr]
+	let mins = time / 60
+	let hrs  = time / 3600
+	let days = time / 86400
+	let wks  = time / 604800
+	let mons = time / 2592000
+	let yrs  = time / 31536000
 	if yrs > 1
 		retu yrs.text[7]
 	elsei mons > 1
@@ -67,10 +60,10 @@ fu! s:humantime(nr)
 		retu hrs.text[3]
 	elsei mins > 1
 		retu mins.text[2]
-	elsei elapsed == 1
-		retu elapsed.text[0]
-	elsei elapsed < 120
-		retu elapsed.text[1]
+	elsei time == 1
+		retu time.text[0]
+	elsei time < 120
+		retu time.text[1]
 	en
 endf
 
@@ -81,7 +74,7 @@ fu! s:syntax()
 			exe 'hi link CtrlPUndo'.ke va
 		en
 	endfo
-	sy match CtrlPUndoT '\d\+ \zs[^ ]\+\ze'
+	sy match CtrlPUndoT '\v\d+ \zs[^ ]+\ze|\d+:\d+:\d+'
 	sy match CtrlPUndoBr '\[\|\]'
 	sy match CtrlPUndoNr '\[\d\+\]' contains=CtrlPUndoBr
 	sy match CtrlPUndoSv 'saved'
@@ -90,7 +83,7 @@ endf
 
 fu! s:dict2list(dict)
 	for ke in keys(a:dict)
-		let a:dict[ke][0] = s:humantime(a:dict[ke][0])
+		let a:dict[ke][0] = s:elapsed(a:dict[ke][0])
 	endfo
 	retu map(keys(a:dict), 'eval(''[v:val, a:dict[v:val]]'')')
 endf
@@ -104,16 +97,29 @@ fu! s:format(...)
 	let current = !empty(a:1[1][2]) ? ' '.a:1[1][2] : ''
 	retu a:1[1][0].' ['.a:1[0].']'.saved.current
 endf
+
+fu! s:formatul(...)
+	let parts = matchlist(a:1,
+		\ '\v^\s+(\d+)\s+\d+\s+([^ ]+\s?[^ ]+|\d+\s\w+\s\w+)(\s*\d*)$')
+	retu parts[2].' ['.parts[1].']'.( parts[3] != '' ? ' saved' : '' )
+endf
 " Public {{{1
 fu! ctrlp#undo#init(undo)
-	let entries = a:undo['entries']
+	let entries = a:undo[0] ? a:undo[1]['entries'] : a:undo[1]
 	if empty(entries) | retu [] | en
 	if has('syntax') && exists('g:syntax_on')
 		cal s:syntax()
 	en
 	let g:ctrlp_nolimit = 1
-	let entries = s:dict2list(s:flatten(entries, a:undo['seq_cur']))
-	retu map(sort(entries, 's:compval'), 's:format(v:val)')
+	if !exists('s:lines')
+		if a:undo[0]
+			let entries = s:dict2list(s:flatten(entries, a:undo[1]['seq_cur']))
+			let s:lines = map(sort(entries, 's:compval'), 's:format(v:val)')
+		el
+			let s:lines = map(reverse(entries), 's:formatul(v:val)')
+		en
+	en
+	retu s:lines
 endf
 
 fu! ctrlp#undo#accept(mode, str)
@@ -126,6 +132,10 @@ endf
 fu! ctrlp#undo#id()
 	retu s:id
 endf
+
+fu! ctrlp#undo#exit()
+	unl! s:lines
+endf
 "}}}
 
 " vim:fen:fdm=marker:fmr={{{,}}}:fdl=0:fdc=1:ts=2:sw=2:sts=2

doc/ctrlp.txt

@@ -729,7 +729,7 @@ Available extensions:~
   * Undo mode:~
     - Name: 'undo'
     - Command: ':CtrlPUndo'
-    - Browse undo history (requires Vim 7.3.005+).
+    - Browse undo history.
 
                                                                    *:CtrlPLine*
   * Line mode:~