Enforce search behavior for "set foldopen-=search"

Sneaking now behaves like / when "foldopen-=search" is set: Closed folds
are considered to be single targets and are not opened when sneaking to
them. They are opened, however, when the default-&foldopen is used or
"foldopen+=search" is set; see a7f59bf.
Resolve justinmk#102.

This does not affect streak-mode (which still ignores &foldopen).

plugin/sneak.vim

@@ -18,16 +18,16 @@ func! sneak#init()
   unlockvar g:sneak#opt
   "options                                 v-- for backwards-compatibility
   let g:sneak#opt = { 'f_reset' : get(g:, 'sneak#nextprev_f', get(g:, 'sneak#f_reset', 1))
-      \ ,'t_reset'      : get(g:, 'sneak#nextprev_t', get(g:, 'sneak#t_reset', 1))
-      \ ,'s_next'       : get(g:, 'sneak#s_next', 0)
-      \ ,'absolute_dir' : get(g:, 'sneak#absolute_dir', 0)
-      \ ,'textobject_z' : get(g:, 'sneak#textobject_z', 1)
-      \ ,'use_ic_scs'   : get(g:, 'sneak#use_ic_scs', 0)
-      \ ,'map_netrw'    : get(g:, 'sneak#map_netrw', 1)
-      \ ,'streak'       : get(g:, 'sneak#streak', 0) && (v:version >= 703) && has("conceal")
-      \ ,'streak_esc'   : get(g:, 'sneak#streak_esc', "\<space>")
-      \ ,'prompt'       : get(g:, 'sneak#prompt', '>')
-      \ }
+        \ ,'t_reset'      : get(g:, 'sneak#nextprev_t', get(g:, 'sneak#t_reset', 1))
+        \ ,'s_next'       : get(g:, 'sneak#s_next', 0)
+        \ ,'absolute_dir' : get(g:, 'sneak#absolute_dir', 0)
+        \ ,'textobject_z' : get(g:, 'sneak#textobject_z', 1)
+        \ ,'use_ic_scs'   : get(g:, 'sneak#use_ic_scs', 0)
+        \ ,'map_netrw'    : get(g:, 'sneak#map_netrw', 1)
+        \ ,'streak'       : get(g:, 'sneak#streak', 0) && (v:version >= 703) && has("conceal")
+        \ ,'streak_esc'   : get(g:, 'sneak#streak_esc', "\<space>")
+        \ ,'prompt'       : get(g:, 'sneak#prompt', '>')
+        \ }
 
   for k in ['f', 't'] "if user mapped f/t to Sneak, then disable f/t reset.
     if maparg(k, 'n') =~# 'Sneak'
@@ -152,9 +152,19 @@ func! sneak#to(op, input, inputlen, count, repeatmotion, reverse, inclusive, str
     let nudge = sneak#util#nudge(!a:reverse) "special case for t
   endif
 
+  " detect whether folds should be opened during search according to &foldopen
+  let l:search_foldopen = !empty(matchstr(&foldopen,"search"))
+
   for i in range(1, max([1, skip])) "jump to the [count]th match
+    " if in a closed fold, jump to end of it for 'set foldopen-=search'
+    let l:winview = winsaveview()
+    if !l:search_foldopen && foldclosed('.') > -1
+      call cursor(a:reverse ? foldclosed('.') : foldclosedend('.'),
+            \ a:reverse ? 1 : '$')
+    endif
     let matchpos = s.dosearch()
-    if 0 == max(matchpos)
+    if 0 == max(matchpos)           " if no search results found
+      call winrestview(l:winview)   " revert jump to end of fold and break
       break
     else
       let nudge = !a:inclusive
@@ -172,9 +182,9 @@ func! sneak#to(op, input, inputlen, count, repeatmotion, reverse, inclusive, str
   endif
   "search succeeded
 
-  " if &foldopen contains search, folds are opened when jumping to matches
-  if !empty(matchstr(&foldopen,"search"))
-      norm! zv
+  " open folds when jumping to matches if necessary
+  if l:search_foldopen
+    norm! zv
   endif
 
   call sneak#hl#removehl()