neovim · teto · Feb 7, 2017 · Feb 25, 2017 · Feb 27, 2017 · Feb 28, 2017
diff --git a/runtime/doc/fold.txt b/runtime/doc/fold.txt
@@ -526,7 +526,8 @@ handles differently: Space, backslash and double-quote. |option-backslash|
 FOLDCOLUMN						*fold-foldcolumn*
 
 'foldcolumn' is a number, which sets the width for a column on the side of the
-window to indicate folds.  When it is zero, there is no foldcolumn.  A normal
+window to indicate folds.  When it is -1, the width is found automatically.
+When it is zero, there is no foldcolumn.  A normal
 value is 4 or 5.  The minimal useful value is 2, although 1 still provides
 some information.  The maximum is 12.
 

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
@@ -2389,6 +2389,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	  stlnc:c	' ' or '='	statusline of the non-current windows
 	  vert:c	'│' or '|'	vertical separators |:vsplit|
 	  fold:c	'·' or '-'	filling 'foldtext'
+	  foldopen:c	'-'		mark the beginning of a fold
+	  foldclose:c	'+'		show a closed fold
+	  foldend:c	'└'		mark the end of a fold
+	  foldsep:c	'|'		open fold middle marker
 	  diff:c	'-'		deleted lines of the 'diff' option
 
 	Any one that is omitted will fall back to the default.  For "stl" and
@@ -2448,6 +2452,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	When non-zero, a column with the specified width is shown at the side
 	of the window which indicates open and closed folds.  The maximum
 	value is 12.
+  When set to -1, adopt the maximum fold level as column width.
 	See |folding|.
 
 			*'foldenable'* *'fen'* *'nofoldenable'* *'nofen'*

diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
@@ -20,6 +20,7 @@
 #include "nvim/vim.h"
 #include "nvim/buffer.h"
 #include "nvim/file_search.h"
+#include "nvim/fold.h"
 #include "nvim/window.h"
 #include "nvim/types.h"
 #include "nvim/ex_docmd.h"
@@ -44,6 +45,45 @@
 # include "api/vim.c.generated.h"
 #endif
 
+
+/// Create a fold from line "start" to line "end" (inclusive) in the current
+/// window.
+/// @param window
+/// @param start starting line
+/// @param end starting end
+/// @param err
+void nvim_fold_create(Window window, Integer start, Integer end, Error *err)
+  FUNC_API_SINCE(4)
+{
+  win_T *win = find_window_by_handle(window, err);
+
+  if (!win) {
+    return;
+  }
+  // Window is 
+  foldCreate(win, start, end);
+}
+
+/// Delete a fold at line "start" in the current window.
+/// When "end" is not 0, delete all folds from "start" to "end".
+/// When "recursive" is TRUE delete recursively.
+/// @param window 
+void nvim_fold_delete(Window window, Integer start, Integer end, Boolean recursive, Error *err)
+  FUNC_API_SINCE(4)
+{
+  win_T *win = find_window_by_handle(window, err);
+
+  if (!win) {
+    return;
+  }
+
+  deleteFold(
+    start,
+    end,
+    recursive,
+    false);
+}
+
 /// Executes an ex-command.
 ///
 /// On parse error: forwards the Vim error; does not update v:errmsg.

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
@@ -2378,8 +2378,9 @@ void get_winopts(buf_T *buf)
     curwin->w_fold_manual = wip->wi_fold_manual;
     curwin->w_foldinvalid = true;
     cloneFoldGrowArray(&wip->wi_folds, &curwin->w_folds);
-  } else
+  } else {
     copy_winopt(&curwin->w_allbuf_opt, &curwin->w_onebuf_opt);
+  }
 
   /* Set 'foldlevel' to 'foldlevelstart' if it's not negative. */
   if (p_fdls >= 0)

diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
@@ -1062,13 +1062,12 @@ struct window_S {
   int w_lines_valid;                /* number of valid entries */
   wline_T     *w_lines;
 
-  garray_T w_folds;                 /* array of nested folds */
-  bool w_fold_manual;               /* when true: some folds are opened/closed
-                                       manually */
-  bool w_foldinvalid;               /* when true: folding needs to be
-                                       recomputed */
-  int w_nrwidth;                    /* width of 'number' and 'relativenumber'
-                                       column being used */
+  garray_T w_folds;         //!< array of nested folds
+  bool w_fold_manual;       //!< when true: some folds are open/closed manually
+  bool w_foldinvalid;       //!< when true: folding needs to be recomputed
+  int w_fdcwidth;           //!< optimal width to draw 'foldcolumn'
+  int w_nrwidth;            //!< width of 'number' and 'relativenumber'
+                            //!< column being used
 
   /*
    * === end of cached values ===
@@ -1166,9 +1165,7 @@ struct window_S {
   int w_fraction;
   int w_prev_fraction_row;
 
-  linenr_T w_nrwidth_line_count;        /* line count when ml_nrwidth_width
-                                         * was computed. */
-  int w_nrwidth_width;                  /* nr of chars to print line count. */
+  int w_nrwidth_width;        //!< nr of chars to print line count. */
 
   qf_info_T   *w_llist;                 /* Location list for this window */
   /*

diff --git a/src/nvim/charset.c b/src/nvim/charset.c
@@ -698,7 +698,7 @@ int chartabsize(char_u *p, colnr_T col)
   RET_WIN_BUF_CHARTABSIZE(curwin, curbuf, p, col)
 }
 
-static int win_chartabsize(win_T *wp, char_u *p, colnr_T col)
+static int win_chartabsize(const win_T *wp, char_u *p, colnr_T col)
 {
   RET_WIN_BUF_CHARTABSIZE(wp, wp->w_buffer, p, col)
 }
@@ -738,7 +738,7 @@ int linetabsize_col(int startcol, char_u *s)
 /// @param len
 ///
 /// @return Number of characters the string will take on the screen.
-unsigned int win_linetabsize(win_T *wp, char_u *line, colnr_T len)
+unsigned int win_linetabsize(const win_T *wp, char_u *line, colnr_T len)
 {
   colnr_T col = 0;
 
@@ -928,7 +928,7 @@ int lbr_chartabsize_adv(char_u *line, char_u **s, colnr_T col)
 /// @param headp
 ///
 /// @return The number of characters taken up on the screen.
-int win_lbr_chartabsize(win_T *wp, char_u *line, char_u *s, colnr_T col, int *headp)
+int win_lbr_chartabsize(const win_T *wp, char_u *line, char_u *s, colnr_T col, int *headp)
 {
   colnr_T col2;
   colnr_T col_adj = 0; /* col + screen size of tab */
@@ -1082,7 +1082,7 @@ int win_lbr_chartabsize(win_T *wp, char_u *line, char_u *s, colnr_T col, int *he
 /// @param headp
 ///
 /// @return The number of characters take up on the screen.
-static int win_nolbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
+static int win_nolbr_chartabsize(const win_T *wp, char_u *s, colnr_T col, int *headp)
 {
   int n;
 
@@ -1107,7 +1107,7 @@ static int win_nolbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
 ///
 /// @param  wp    window
 /// @param  vcol  column number
-bool in_win_border(win_T *wp, colnr_T vcol)
+bool in_win_border(const win_T *wp, colnr_T vcol)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1)
 {
   int width1;             // width of first line (after line number)

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
@@ -5776,22 +5776,25 @@ comp_textwidth (
 )
 {
   int textwidth;
+  int fdc = compute_foldcolumn(curwin, 0);
 
   textwidth = curbuf->b_p_tw;
   if (textwidth == 0 && curbuf->b_p_wm) {
     /* The width is the window width minus 'wrapmargin' minus all the
      * things that add to the margin. */
     textwidth = curwin->w_width - curbuf->b_p_wm;
-    if (cmdwin_type != 0)
+    if (cmdwin_type != 0) {
       textwidth -= 1;
-    textwidth -= curwin->w_p_fdc;
+    }
+    textwidth -= fdc;
 
     if (signcolumn_on(curwin)) {
         textwidth -= 1;
     }
 
-    if (curwin->w_p_nu || curwin->w_p_rnu)
+    if (curwin->w_p_nu || curwin->w_p_rnu) {
       textwidth -= 8;
+    }
   }
   if (textwidth < 0)
     textwidth = 0;

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
@@ -8861,7 +8861,10 @@ static void f_foldtextresult(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
   fold_count = foldedCount(curwin, lnum, &foldinfo);
   if (fold_count > 0) {
-    text = get_foldtext(curwin, lnum, lnum + fold_count - 1, &foldinfo, buf);
+    text = get_foldtext(curwin, lnum, lnum + fold_count - 1,
+                        foldinfo.fi_level, buf);
+    text = get_foldtext(curwin, lnum, lnum + fold_count - 1,
+                        foldinfo.fi_level, buf);
     if (text == buf) {
       text = vim_strsave(text);
     }
@@ -10609,6 +10612,7 @@ static void f_has(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     "find_in_path",
     "float",
     "folding",
+    "folding_fillchars",
 #if defined(UNIX)
     "fork",
 #endif

diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
@@ -9847,8 +9847,9 @@ static void ex_match(exarg_T *eap)
 
 static void ex_fold(exarg_T *eap)
 {
-  if (foldManualAllowed(TRUE))
-    foldCreate(eap->line1, eap->line2);
+  if (foldManualAllowed(TRUE)) {
+    foldCreate(curwin, eap->line1, eap->line2);
+  }
 }
 
 static void ex_foldopen(exarg_T *eap)