foldcolumn: allow auto:X

Similar to signcolumn, allow foldcolumn to adapt itself to the number of
folds.

Regression:
vim supports a maximum fdc of 12, this limits it to 9.

1 files changed, 16 insertions, 8 deletions

diff --git a/src/nvim/option.c b/src/nvim/option.c
index 478c9a0ff8..e990cb5214 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -315,6 +315,9 @@ static char *(p_scl_values[]) =       { "yes", "no", "auto", "auto:1", "auto:2",
   "auto:3", "auto:4", "auto:5", "auto:6", "auto:7", "auto:8", "auto:9",
   "yes:1", "yes:2", "yes:3", "yes:4", "yes:5", "yes:6", "yes:7", "yes:8",
   "yes:9", NULL };
+static char *(p_fdc_values[]) =       { "auto:1", "auto:2",
+  "auto:3", "auto:4", "auto:5", "auto:6", "auto:7", "auto:8", "auto:9",
+  "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", NULL };
 
 /// All possible flags for 'shm'.
 static char_u SHM_ALL[] = {
@@ -2322,6 +2325,7 @@ void check_buf_options(buf_T *buf)
  * Does NOT check for P_ALLOCED flag!
  */
 void free_string_option(char_u *p)
+
 {
   if (p != empty_option) {
     xfree(p);
@@ -3199,6 +3203,11 @@ ambw_end:
     if (check_opt_strings(*varp, p_scl_values, false) != OK) {
       errmsg = e_invarg;
     }
+  } else if (varp == &curwin->w_p_fdc || varp == &curwin->w_allbuf_opt.wo_fdc) {
+    // 'foldcolumn'
+    if (check_opt_strings(*varp, p_fdc_values, false) != OK) {
+      errmsg = e_invarg;
+    }
   } else if (varp == &p_pt) {
     // 'pastetoggle': translate key codes like in a mapping
     if (*p_pt) {
@@ -4363,12 +4372,6 @@ static char *set_num_option(int opt_idx, char_u *varp, long value,
     if (value < 0) {
       errmsg = e_positive;
     }
-  } else if (pp == &curwin->w_p_fdc || pp == &curwin->w_allbuf_opt.wo_fdc) {
-    if (value < 0) {
-      errmsg = e_positive;
-    } else if (value > 12) {
-      errmsg = e_invarg;
-    }
   } else if (pp == &curwin->w_p_cole || pp == &curwin->w_allbuf_opt.wo_cole) {
     if (value < 0) {
       errmsg = e_positive;
@@ -5936,8 +5939,9 @@ void copy_winopt(winopt_T *from, winopt_T *to)
   to->wo_diff_saved = from->wo_diff_saved;
   to->wo_cocu = vim_strsave(from->wo_cocu);
   to->wo_cole = from->wo_cole;
-  to->wo_fdc = from->wo_fdc;
-  to->wo_fdc_save = from->wo_fdc_save;
+  to->wo_fdc = vim_strsave(from->wo_fdc);
+  to->wo_fdc_save = from->wo_diff_saved
+                    ? vim_strsave(from->wo_fdc_save) : empty_option;
   to->wo_fen = from->wo_fen;
   to->wo_fen_save = from->wo_fen_save;
   to->wo_fdi = vim_strsave(from->wo_fdi);
@@ -5973,6 +5977,8 @@ void check_win_options(win_T *win)
  */
 static void check_winopt(winopt_T *wop)
 {
+  check_string_option(&wop->wo_fdc);
+  check_string_option(&wop->wo_fdc_save);
   check_string_option(&wop->wo_fdi);
   check_string_option(&wop->wo_fdm);
   check_string_option(&wop->wo_fdm_save);
@@ -5995,6 +6001,8 @@ static void check_winopt(winopt_T *wop)
  */
 void clear_winopt(winopt_T *wop)
 {
+  clear_string_option(&wop->wo_fdc);
+  clear_string_option(&wop->wo_fdc_save);
   clear_string_option(&wop->wo_fdi);
   clear_string_option(&wop->wo_fdm);
   clear_string_option(&wop->wo_fdm_save);