vim-patch:8.1.0105: all tab stops are the same

Problem:    All tab stops are the same.
Solution:   Add the variable tabstop feature. (Christian Brabandt,
            closes vim/vim#2711)
https://github.com/vim/vim/commit/04958cbaf25eea27eceedaa987adfb354ad5f7fd

22 files changed, 1458 insertions, 249 deletions

diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index f3ed086933..ed40642d0c 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -934,6 +934,10 @@ This replaces each 'E' character with a euro sign.  Read more in |<Char->|.
 			this (that's a good habit anyway).
 			`:retab!` may also change a sequence of spaces by
 			<Tab> characters, which can mess up a printf().
+			A list of tab widths separated by commas may be used
+			in place of a single tabstop.  Each value in the list
+			represents the width of one tabstop, except the final
+			value which applies to all following tabstops.
 
 							*retab-example*
 Example for using autocommands and ":retab" to edit a file which is stored
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 112958f78b..164c6fb8e0 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -7915,6 +7915,11 @@ shiftwidth()						*shiftwidth()*
 			endif
 <		And then use s:sw() instead of &sw.
 
+		When there is one argument {col} this is used as column number
+		for which to return the 'shiftwidth' value. This matters for the
+		'vartabstop' feature. If no {col} argument is given, column 1
+		will be assumed.
+
 sign_define({name} [, {dict}])				*sign_define()*
 		Define a new sign named {name} or modify the attributes of an
 		existing sign.  This is similar to the |:sign-define| command.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index c4d5df84cf..decf226b12 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -5621,6 +5621,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	The 'L' flag in 'cpoptions' changes how tabs are used when 'list' is
 	set.
 
+	The value of 'softtabstop' will be ignored if |'varsofttabstop'| is set
+	to anything other than an empty string.
+
 						*'spell'* *'nospell'*
 'spell'			boolean	(default off)
 			local to window
@@ -6158,6 +6161,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	   though.  Otherwise aligned comments will be wrong when 'tabstop' is
 	   changed.
 
+	The value of 'tabstop' will be ignored if |'vartabstop'| is set to
+	anything other than an empty string.
+
 			*'tagbsearch'* *'tbs'* *'notagbsearch'* *'notbs'*
 'tagbsearch' 'tbs'	boolean	(default on)
 			global
@@ -6542,6 +6548,38 @@ A jump table for the options with a short description can be found at |Q_op|.
 	written to disk (see |crash-recovery|).  Also used for the
 	|CursorHold| autocommand event.
 
+					*'varsofttabstop'* *'vsts'*
+'varsofttabstop' 'vsts'	string	(default "")
+			local to buffer
+	A list of the number of spaces that a <Tab> counts for while editing,
+	such as inserting a <Tab> or using <BS>.  It "feels" like variable-
+	width <Tab>s are being inserted, while in fact a mixture of spaces
+	and <Tab>s is used.  Tab widths are separated with commas, with the
+	final value applying to all subsequent tabs.
+
+	For example, when editing assembly language files where statements
+	start in the 8th column and comments in the 40th, it may be useful
+	to use the following: >
+		:set varsofttabstop=8,32,8
+<	This will set soft tabstops at the 8th and 40th columns, and at every
+	8th column thereafter.
+
+	Note that the value of |'softtabstop'| will be ignored while
+	'varsofttabstop' is set.
+
+						*'vartabstop'* *'vts'*
+'vartabstop' 'vts'	string	(default "")
+			local to buffer
+	A list of the number of spaces that a <Tab> in the file counts for,
+	separated by commas.  Each value corresponds to one tab, with the
+	final value applying to all subsequent tabs. For example: >
+		:set vartabstop=4,20,10,8
+<	This will make the first tab 4 spaces wide, the second 20 spaces,
+	the third 10 spaces, and all following tabs 8 spaces.
+
+	Note that the value of |'tabstop'| will be ignored while 'vartabstop'
+	is set.
+
 						*'verbose'* *'vbs'*
 'verbose' 'vbs'		number	(default 0)
 			global
diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index 6b3328a5d4..60dc6fdd31 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -810,6 +810,14 @@ call <SID>OptionL("ts")
 call append("$", "shiftwidth\tnumber of spaces used for each step of (auto)indent")
 call append("$", "\t(local to buffer)")
 call <SID>OptionL("sw")
+if has("vartabs")
+  call append("$", "vartabstop\tlist of number of spaces a tab counts for")
+  call append("$", "\t(local to buffer)")
+  call <SID>OptionL("vts")
+  call append("$", "varsofttabstop\tlist of number of spaces a soft tabsstop counts for")
+  call append("$", "\t(local to buffer)")
+  call <SID>OptionL("vsts")
+endif
 call append("$", "smarttab\ta <Tab> in an indent inserts 'shiftwidth' spaces")
 call <SID>BinOptionG("sta", &sta)
 call append("$", "softtabstop\tif non-zero, number of spaces to insert for a <Tab>")
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index c42a0e2dad..1daedb90b5 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -282,7 +282,7 @@ int open_buffer(
 
   // Set/reset the Changed flag first, autocmds may change the buffer.
   // Apply the automatic commands, before processing the modelines.
-  // So the modelines have priority over auto commands.
+  // So the modelines have priority over autocommands.
 
   // When reading stdin, the buffer contents always needs writing, so set
   // the changed flag.  Unless in readonly mode: "ls | nvim -R -".
@@ -1946,6 +1946,20 @@ void free_buf_options(buf_T *buf, int free_p_ff)
   clear_string_option(&buf->b_p_fo);
   clear_string_option(&buf->b_p_flp);
   clear_string_option(&buf->b_p_isk);
+  clear_string_option(&buf->b_p_vsts);
+  if (buf->b_p_vsts_nopaste) {
+    xfree(buf->b_p_vsts_nopaste);
+  }
+  buf->b_p_vsts_nopaste = NULL;
+  if (buf->b_p_vsts_array) {
+    xfree(buf->b_p_vsts_array);
+  }
+  buf->b_p_vsts_array = NULL;
+  clear_string_option(&buf->b_p_vts);
+  if (buf->b_p_vts_array) {
+    xfree(buf->b_p_vts_array);
+  }
+  buf->b_p_vts_array = NULL;
   clear_string_option(&buf->b_p_keymap);
   keymap_ga_clear(&buf->b_kmap_ga);
   ga_clear(&buf->b_kmap_ga);
@@ -5375,8 +5389,8 @@ bool bt_terminal(const buf_T *const buf)
   return buf != NULL && buf->b_p_bt[0] == 't';
 }
 
-// Return true if "buf" is a "nofile", "acwrite" or "terminal" buffer.
-// This means the buffer name is not a file name.
+// Return true if "buf" is a "nofile", "acwrite", "terminal" or "prompt"
+// buffer.  This means the buffer name is not a file name.
 bool bt_nofile(const buf_T *const buf)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
@@ -5386,7 +5400,8 @@ bool bt_nofile(const buf_T *const buf)
                          || buf->b_p_bt[0] == 'p');
 }
 
-// Return true if "buf" is a "nowrite", "nofile" or "terminal" buffer.
+// Return true if "buf" is a "nowrite", "nofile", "terminal" or "prompt"
+// buffer.
 bool bt_dontwrite(const buf_T *const buf)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index e8038e7281..a4105e2796 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -743,6 +743,11 @@ struct file_buffer {
   long b_p_wm;                  ///< 'wrapmargin'
   long b_p_wm_nobin;            ///< b_p_wm saved for binary mode
   long b_p_wm_nopaste;          ///< b_p_wm saved for paste mode
+  char_u *b_p_vsts;             ///< 'varsofttabstop'
+  long *b_p_vsts_array;          ///< 'varsofttabstop' in internal format
+  char_u *b_p_vsts_nopaste;     ///< b_p_vsts saved for paste mode
+  char_u *b_p_vts;              ///< 'vartabstop'
+  long *b_p_vts_array;           ///< 'vartabstop' in internal format
   char_u *b_p_keymap;           ///< 'keymap'
 
   // local values for options which are normally global
diff --git a/src/nvim/change.c b/src/nvim/change.c
index 0f5081c94c..38bd591eca 100644
--- a/src/nvim/change.c
+++ b/src/nvim/change.c
@@ -828,6 +828,7 @@ int copy_indent(int size, char_u *src)
   int tab_pad;
   int ind_done;
   int round;
+  int ind_col;
 
   // Round 1: compute the number of characters needed for the indent
   // Round 2: copy the characters.
@@ -835,13 +836,15 @@ int copy_indent(int size, char_u *src)
     todo = size;
     ind_len = 0;
     ind_done = 0;
+    ind_col = 0;
     s = src;
 
     // Count/copy the usable portion of the source line.
     while (todo > 0 && ascii_iswhite(*s)) {
       if (*s == TAB) {
-        tab_pad = (int)curbuf->b_p_ts
-                  - (ind_done % (int)curbuf->b_p_ts);
+        tab_pad = tabstop_padding(ind_done,
+                                  curbuf->b_p_ts,
+                                  curbuf->b_p_vts_array);
 
         // Stop if this tab will overshoot the target.
         if (todo < tab_pad) {
@@ -849,9 +852,11 @@ int copy_indent(int size, char_u *src)
         }
         todo -= tab_pad;
         ind_done += tab_pad;
+        ind_col += tab_pad;
       } else {
         todo--;
         ind_done++;
+        ind_col++;
       }
       ind_len++;
 
@@ -862,11 +867,12 @@ int copy_indent(int size, char_u *src)
     }
 
     // Fill to next tabstop with a tab, if possible.
-    tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts, curbuf->b_p_vts_array);
 
     if ((todo >= tab_pad) && !curbuf->b_p_et) {
       todo -= tab_pad;
       ind_len++;
+      ind_col += tab_pad;
 
       if (p != NULL) {
         *p++ = TAB;
@@ -874,12 +880,20 @@ int copy_indent(int size, char_u *src)
     }
 
     // Add tabs required for indent.
-    while (todo >= (int)curbuf->b_p_ts && !curbuf->b_p_et) {
-      todo -= (int)curbuf->b_p_ts;
-      ind_len++;
-
-      if (p != NULL) {
-        *p++ = TAB;
+    if (!curbuf->b_p_et) {
+      for (;;) {
+        tab_pad = tabstop_padding(ind_col,
+                                  curbuf->b_p_ts,
+                                  curbuf->b_p_vts_array);
+        if (todo < tab_pad) {
+          break;
+        }
+        todo -= tab_pad;
+        ind_len++;
+        ind_col += tab_pad;
+        if (p != NULL) {
+          *p++ = TAB;
+        }
       }
     }
 
@@ -1029,7 +1043,9 @@ int open_line(
       || do_si
       ) {
     // count white space on current line
-    newindent = get_indent_str(saved_line, (int)curbuf->b_p_ts, false);
+    newindent = get_indent_str_vtab(saved_line,
+                                    curbuf->b_p_ts,
+                                    curbuf->b_p_vts_array, false);
     if (newindent == 0 && !(flags & OPENLINE_COM_LIST)) {
       newindent = second_line_indent;  // for ^^D command in insert mode
     }
@@ -1453,7 +1469,9 @@ int open_line(
         if (curbuf->b_p_ai
             || do_si
             ) {
-          newindent = get_indent_str(leader, (int)curbuf->b_p_ts, false);
+          newindent = get_indent_str_vtab(leader,
+                                          curbuf->b_p_ts,
+                                          curbuf->b_p_vts_array, false);
         }
 
         // Add the indent offset
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 5ad1fe0dfd..e2d844a351 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -744,8 +744,7 @@ int vim_strnsize(char_u *s, int len)
 /// @return Number of characters.
 #define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
   if (*(p) == TAB && (!(wp)->w_p_list || wp->w_p_lcs_chars.tab1)) { \
-    const int ts = (int)(buf)->b_p_ts; \
-    return (ts - (int)(col % ts)); \
+    return tabstop_padding(col, (buf)->b_p_ts, (buf)->b_p_vts_array); \
   } else { \
     return ptr2cells(p); \
   }
@@ -1143,8 +1142,9 @@ static int win_nolbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
   int n;
 
   if ((*s == TAB) && (!wp->w_p_list || wp->w_p_lcs_chars.tab1)) {
-    n = (int)wp->w_buffer->b_p_ts;
-    return n - (col % n);
+    return tabstop_padding(col,
+                           wp->w_buffer->b_p_ts,
+                           wp->w_buffer->b_p_vts_array);
   }
   n = ptr2cells(s);
 
@@ -1211,6 +1211,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
   char_u *line;   // start of the line
   int incr;
   int head;
+  long *vts = wp->w_buffer->b_p_vts_array;
   int ts = (int)wp->w_buffer->b_p_ts;
   int c;
 
@@ -1251,7 +1252,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
 
       // A tab gets expanded, depending on the current column
       if (c == TAB) {
-        incr = ts - (vcol % ts);
+        incr = tabstop_padding(vcol, ts, vts);
       } else {
         // For utf-8, if the byte is >= 0x80, need to look at
         // further bytes to find the cell width.
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index b5d5d67e90..110494bb5c 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -597,7 +597,10 @@ static int insert_check(VimState *state)
     s->mincol = curwin->w_wcol;
     validate_cursor_col();
 
-    if (curwin->w_wcol < s->mincol - curbuf->b_p_ts
+    if (
+        curwin->w_wcol < s->mincol - tabstop_at(get_nolist_virtcol(),
+                                                curbuf->b_p_ts,
+                                                curbuf->b_p_vts_array)
         && curwin->w_wrow == curwin->w_winrow
         + curwin->w_height_inner - 1 - get_scrolloff_value(curwin)
         && (curwin->w_cursor.lnum != curwin->w_topline
@@ -8178,24 +8181,19 @@ static bool ins_bs(int c, int mode, int *inserted_space_p)
     /*
      * Handle deleting one 'shiftwidth' or 'softtabstop'.
      */
-    if (       mode == BACKSPACE_CHAR
-               && ((p_sta && in_indent)
-                   || (get_sts_value() != 0
-                       && curwin->w_cursor.col > 0
-                       && (*(get_cursor_pos_ptr() - 1) == TAB
-                           || (*(get_cursor_pos_ptr() - 1) == ' '
-                               && (!*inserted_space_p
-                                   || arrow_used)))))) {
-      int ts;
+    if (mode == BACKSPACE_CHAR
+        && ((p_sta && in_indent)
+            || ((get_sts_value() != 0
+                 || tabstop_count(curbuf->b_p_vsts_array))
+                && curwin->w_cursor.col > 0
+                && (*(get_cursor_pos_ptr() - 1) == TAB
+                    || (*(get_cursor_pos_ptr() - 1) == ' '
+                        && (!*inserted_space_p || arrow_used)))))) {
       colnr_T vcol;
       colnr_T want_vcol;
       colnr_T start_vcol;
 
-      *inserted_space_p = FALSE;
-      if (p_sta && in_indent)
-        ts = get_sw_value(curbuf);
-      else
-        ts = get_sts_value();
+      *inserted_space_p = false;
       // Compute the virtual column where we want to be.  Since
       // 'showbreak' may get in the way, need to get the last column of
       // the previous character.
@@ -8204,7 +8202,13 @@ static bool ins_bs(int c, int mode, int *inserted_space_p)
       dec_cursor();
       getvcol(curwin, &curwin->w_cursor, NULL, NULL, &want_vcol);
       inc_cursor();
-      want_vcol = (want_vcol / ts) * ts;
+      if (p_sta && in_indent) {
+        want_vcol = (want_vcol / curbuf->b_p_sw) * curbuf->b_p_sw;
+      } else {
+        want_vcol = tabstop_start(want_vcol,
+                                  curbuf->b_p_sts,
+                                  curbuf->b_p_vsts_array);
+      }
 
       // delete characters until we are at or before want_vcol
       while (vcol > want_vcol
@@ -8669,10 +8673,19 @@ static bool ins_tab(void)
     can_cindent = false;
   }
 
-  // When nothing special, insert TAB like a normal character
+  // When nothing special, insert TAB like a normal character.
   if (!curbuf->b_p_et
-      && !(p_sta && ind && curbuf->b_p_ts != get_sw_value(curbuf))
-      && get_sts_value() == 0) {
+      && !(
+          p_sta
+          && ind
+          // These five lines mean 'tabstop' != 'shiftwidth'
+          && ((tabstop_count(curbuf->b_p_vts_array) > 1)
+              || (tabstop_count(curbuf->b_p_vts_array) == 1
+                  && tabstop_first(curbuf->b_p_vts_array)
+                  != get_sw_value(curbuf))
+              || (tabstop_count(curbuf->b_p_vts_array) == 0
+                  && curbuf->b_p_ts != get_sw_value(curbuf))))
+      && tabstop_count(curbuf->b_p_vsts_array) == 0 && get_sts_value() == 0) {
     return true;
   }
 
@@ -8686,16 +8699,22 @@ static bool ins_tab(void)
   can_si_back = false;
   AppendToRedobuff("\t");
 
-  if (p_sta && ind) {  // insert tab in indent, use "shiftwidth"
-    temp = get_sw_value(curbuf);
-  } else if (curbuf->b_p_sts != 0) {  // use "softtabstop" when set
-    temp = get_sts_value();
-  } else {  // otherwise use "tabstop"
-    temp = (int)curbuf->b_p_ts;
+  if (p_sta && ind) {  // insert tab in indent, use 'shiftwidth'
+    temp = (int)curbuf->b_p_sw;
+    temp -= get_nolist_virtcol() % temp;
+  } else if (tabstop_count(curbuf->b_p_vsts_array) > 0
+             || curbuf->b_p_sts > 0) {
+    // use 'softtabstop' when set
+    temp = tabstop_padding(get_nolist_virtcol(),
+                           curbuf->b_p_sts,
+                           curbuf->b_p_vsts_array);
+  } else {
+    // otherwise use 'tabstop'
+    temp = tabstop_padding(get_nolist_virtcol(),
+                           curbuf->b_p_ts,
+                           curbuf->b_p_vts_array);
   }
 
-  temp -= get_nolist_virtcol() % temp;
-
   /*
    * Insert the first space with ins_char().	It will delete one char in
    * replace mode.  Insert the rest with ins_str(); it will not delete any
@@ -8716,7 +8735,9 @@ static bool ins_tab(void)
   /*
    * When 'expandtab' not set: Replace spaces by TABs where possible.
    */
-  if (!curbuf->b_p_et && (get_sts_value() || (p_sta && ind))) {
+  if (!curbuf->b_p_et && (tabstop_count(curbuf->b_p_vsts_array) > 0
+                          || get_sts_value() > 0
+                          || (p_sta && ind))) {
     char_u          *ptr;
     char_u          *saved_line = NULL;         // init for GCC
     pos_T pos;
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 650b4e3882..eeaaf7dbd1 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -4312,6 +4312,7 @@ static void f_has(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     "title",
     "user-commands",        // was accidentally included in 5.4
     "user_commands",
+    "vartabs",
     "vertsplit",
     "virtualedit",
     "visual",
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 854faf5377..d679a3c8f8 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -712,14 +712,15 @@ void ex_retab(exarg_T *eap)
   long len;
   long col;
   long vcol;
-  long start_col = 0;                   /* For start of white-space string */
-  long start_vcol = 0;                  /* For start of white-space string */
-  int temp;
+  long start_col = 0;                   // For start of white-space string
+  long start_vcol = 0;                  // For start of white-space string
   long old_len;
   char_u      *ptr;
-  char_u      *new_line = (char_u *)1;      /* init to non-NULL */
-  int did_undo;                         /* called u_save for current line */
-  int new_ts;
+  char_u      *new_line = (char_u *)1;  // init to non-NULL
+  int did_undo;                         // called u_save for current line
+  long *new_ts = 0;
+  char_u *new_ts_str;  // string value of tab argument
+
   int save_list;
   linenr_T first_line = 0;              /* first changed line */
   linenr_T last_line = 0;               /* last changed line */
@@ -727,14 +728,23 @@ void ex_retab(exarg_T *eap)
   save_list = curwin->w_p_list;
   curwin->w_p_list = 0;             /* don't want list mode here */
 
-  new_ts = getdigits_int(&(eap->arg), false, -1);
-  if (new_ts < 0) {
-    EMSG(_(e_positive));
+  new_ts_str = eap->arg;
+  if (!tabstop_set(eap->arg, &new_ts)) {
     return;
   }
-  if (new_ts == 0)
-    new_ts = curbuf->b_p_ts;
-  for (lnum = eap->line1; !got_int && lnum <= eap->line2; ++lnum) {
+  while (ascii_isdigit(*(eap->arg)) || *(eap->arg) == ',') {
+    (eap->arg)++;
+  }
+
+  // This ensures that either new_ts and new_ts_str are freshly allocated,
+  // or new_ts points to an existing array and new_ts_str is null.
+  if (new_ts == 0) {
+    new_ts = curbuf->b_p_vts_array;
+    new_ts_str = NULL;
+  } else {
+    new_ts_str = vim_strnsave(new_ts_str, eap->arg - new_ts_str);
+  }
+  for (lnum = eap->line1; !got_int && lnum <= eap->line2; lnum++) {
     ptr = ml_get(lnum);
     col = 0;
     vcol = 0;
@@ -758,13 +768,14 @@ void ex_retab(exarg_T *eap)
           len = num_spaces = vcol - start_vcol;
           num_tabs = 0;
           if (!curbuf->b_p_et) {
-            temp = new_ts - (start_vcol % new_ts);
-            if (num_spaces >= temp) {
-              num_spaces -= temp;
-              num_tabs++;
-            }
-            num_tabs += num_spaces / new_ts;
-            num_spaces -= (num_spaces / new_ts) * new_ts;
+            int t, s;
+
+            tabstop_fromto(start_vcol, vcol,
+                           tabstop_count(new_ts) ? 0 : curbuf->b_p_ts,
+                           new_ts,
+                           &t, &s);
+            num_tabs = t;
+            num_spaces = s;
           }
           if (curbuf->b_p_et || got_tab
               || (num_spaces + num_tabs < len)) {
@@ -817,15 +828,42 @@ void ex_retab(exarg_T *eap)
   if (got_int)
     EMSG(_(e_interr));
 
-  if (curbuf->b_p_ts != new_ts)
+  // If a single value was given then it can be considered equal to
+  // either the value of 'tabstop' or the value of 'vartabstop'.
+  if (tabstop_count(curbuf->b_p_vts_array) == 0
+      && tabstop_count(new_ts) == 1
+      && curbuf->b_p_ts == tabstop_first(new_ts)) {
+    // not changed
+  } else if (tabstop_count(curbuf->b_p_vts_array) > 0
+             && tabstop_eq(curbuf->b_p_vts_array, new_ts)) {
+    // not changed
+  } else {
     redraw_curbuf_later(NOT_VALID);
+  }
   if (first_line != 0) {
     changed_lines(first_line, 0, last_line + 1, 0L, true);
   }
 
   curwin->w_p_list = save_list;         /* restore 'list' */
 
-  curbuf->b_p_ts = new_ts;
+  if (new_ts_str != NULL) {  // set the new tabstop
+    // If 'vartabstop' is in use or if the value given to retab has more
+    // than one tabstop then update 'vartabstop'.
+    long *old_vts_ary = curbuf->b_p_vts_array;
+
+    if (tabstop_count(old_vts_ary) > 0 || tabstop_count(new_ts) > 1) {
+      set_string_option_direct("vts", -1, new_ts_str,
+                               OPT_FREE | OPT_LOCAL, 0);
+      xfree(new_ts_str);
+      curbuf->b_p_vts_array = new_ts;
+      xfree(old_vts_ary);
+    } else {
+      // 'vartabstop' wasn't in use and a single value was given to
+      // retab then update 'tabstop'.
+      curbuf->b_p_ts = tabstop_first(new_ts);
+      xfree(new_ts);
+    }
+  }
   coladvance(curwin->w_curswant);
 
   u_clearline();
diff --git a/src/nvim/hardcopy.c b/src/nvim/hardcopy.c
index 4ec949759c..abba5425e7 100644
--- a/src/nvim/hardcopy.c
+++ b/src/nvim/hardcopy.c
@@ -890,8 +890,11 @@ static colnr_T hardcopy_line(prt_settings_T *psettings, int page_line, prt_pos_T
      * Appropriately expand any tabs to spaces.
      */
     if (line[col] == TAB || tab_spaces != 0) {
-      if (tab_spaces == 0)
-        tab_spaces = (int)(curbuf->b_p_ts - (print_pos % curbuf->b_p_ts));
+      if (tab_spaces == 0) {
+        tab_spaces = tabstop_padding(print_pos,
+                                     curbuf->b_p_ts,
+                                     curbuf->b_p_vts_array);
+      }
 
       while (tab_spaces > 0) {
         need_break = mch_print_text_out((char_u *)" ", 1);
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index fae971b3b3..92ecbe160b 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -34,14 +34,20 @@
 // Count the size (in window cells) of the indent in the current line.
 int get_indent(void)
 {
-  return get_indent_str(get_cursor_line_ptr(), (int)curbuf->b_p_ts, false);
+  return get_indent_str_vtab(get_cursor_line_ptr(),
+                             curbuf->b_p_ts,
+                             curbuf->b_p_vts_array,
+                             false);
 }
 
 
 // Count the size (in window cells) of the indent in line "lnum".
 int get_indent_lnum(linenr_T lnum)
 {
-  return get_indent_str(ml_get(lnum), (int)curbuf->b_p_ts, false);
+  return get_indent_str_vtab(ml_get(lnum),
+                             curbuf->b_p_ts,
+                             curbuf->b_p_vts_array,
+                             false);
 }
 
 
@@ -49,7 +55,10 @@ int get_indent_lnum(linenr_T lnum)
 // "buf".
 int get_indent_buf(buf_T *buf, linenr_T lnum)
 {
-  return get_indent_str(ml_get_buf(buf, lnum, false), (int)buf->b_p_ts, false);
+  return get_indent_str_vtab(ml_get_buf(buf, lnum, false),
+                             curbuf->b_p_ts,
+                             buf->b_p_vts_array,
+                             false);
 }
 
 
@@ -82,6 +91,30 @@ int get_indent_str(const char_u *ptr, int ts, int list)
   return count;
 }
 
+// Count the size (in window cells) of the indent in line "ptr", using
+// variable tabstops.
+// if "list" is true, count only screen size for tabs.
+int get_indent_str_vtab(const char_u *ptr, long ts, long *vts, bool list)
+{
+  int count = 0;
+
+  for (; *ptr; ptr++) {
+    if (*ptr == TAB) {  // count a tab for what it is worth
+      if (!list || curwin->w_p_lcs_chars.tab1) {
+        count += tabstop_padding(count, ts, vts);
+      } else {
+        // In list mode, when tab is not set, count screen char width
+        // for Tab, displays: ^I
+        count += ptr2cells(ptr);
+      }
+    } else if (*ptr == ' ') {
+      count++;  // count a space for one
+    } else {
+      break;
+    }
+  }
+  return count;
+}
 
 // Set the indent of the current line.
 // Leaves the cursor on the first non-blank in the line.
@@ -104,6 +137,7 @@ int set_indent(int size, int flags)
   int line_len;
   int doit = false;
   int ind_done = 0;  // Measured in spaces.
+  int ind_col = 0;
   int tab_pad;
   int retval = false;
 
@@ -130,7 +164,9 @@ int set_indent(int size, int flags)
       // Count as many characters as we can use.
       while (todo > 0 && ascii_iswhite(*p)) {
         if (*p == TAB) {
-          tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+          tab_pad = tabstop_padding(ind_done,
+                                    curbuf->b_p_ts,
+                                    curbuf->b_p_vts_array);
 
           // Stop if this tab will overshoot the target.
           if (todo < tab_pad) {
@@ -147,35 +183,41 @@ int set_indent(int size, int flags)
         p++;
       }
 
+      // These diverge from this point.
+      ind_col = ind_done;
       // Set initial number of whitespace chars to copy if we are
       // preserving indent but expandtab is set.
       if (curbuf->b_p_et) {
         orig_char_len = ind_len;
       }
-
       // Fill to next tabstop with a tab, if possible.
-      tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
-
+      tab_pad = tabstop_padding(ind_done,
+                                curbuf->b_p_ts,
+                                curbuf->b_p_vts_array);
       if ((todo >= tab_pad) && (orig_char_len == -1)) {
         doit = true;
         todo -= tab_pad;
         ind_len++;
 
         // ind_done += tab_pad;
+        ind_col += tab_pad;
       }
     }
 
     // Count tabs required for indent.
-    while (todo >= (int)curbuf->b_p_ts) {
+    for (;;) {
+      tab_pad = tabstop_padding(ind_col, curbuf->b_p_ts, curbuf->b_p_vts_array);
+      if (todo < tab_pad) {
+        break;
+      }
       if (*p != TAB) {
         doit = true;
       } else {
         p++;
       }
-      todo -= (int)curbuf->b_p_ts;
+      todo -= tab_pad;
       ind_len++;
-
-      // ind_done += (int)curbuf->b_p_ts;
+      ind_col += tab_pad;
     }
   }
 
@@ -255,7 +297,9 @@ int set_indent(int size, int flags)
 
       while (todo > 0 && ascii_iswhite(*p)) {
         if (*p == TAB) {
-          tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+          tab_pad = tabstop_padding(ind_done,
+                                    curbuf->b_p_ts,
+                                    curbuf->b_p_vts_array);
 
           // Stop if this tab will overshoot the target.
           if (todo < tab_pad) {
@@ -272,18 +316,28 @@ int set_indent(int size, int flags)
       }
 
       // Fill to next tabstop with a tab, if possible.
-      tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+      tab_pad = tabstop_padding(ind_done,
+                                curbuf->b_p_ts,
+                                curbuf->b_p_vts_array);
 
       if (todo >= tab_pad) {
         *s++ = TAB;
         todo -= tab_pad;
+        ind_done += tab_pad;
       }
       p = skipwhite(p);
     }
 
-    while (todo >= (int)curbuf->b_p_ts) {
+    for (;;) {
+      tab_pad = tabstop_padding(ind_done,
+                                curbuf->b_p_ts,
+                                curbuf->b_p_vts_array);
+      if (todo < tab_pad) {
+        break;
+      }
       *s++ = TAB;
-      todo -= (int)curbuf->b_p_ts;
+      todo -= tab_pad;
+      ind_done += tab_pad;
     }
   }
 
@@ -387,6 +441,7 @@ int get_breakindent_win(win_T *wp, const char_u *line)
   static long prev_ts = 0;  // Cached tabstop value.
   static const char_u *prev_line = NULL;  // cached pointer to line.
   static varnumber_T prev_tick = 0;  // Changedtick of cached value.
+  static long *prev_vts = NULL;    // Cached vartabs values.
   int bri = 0;
   // window width minus window margin space, i.e. what rests for text
   const int eff_wwidth = wp->w_width_inner
@@ -396,11 +451,16 @@ int get_breakindent_win(win_T *wp, const char_u *line)
 
   // used cached indent, unless pointer or 'tabstop' changed
   if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts
-      || prev_tick != buf_get_changedtick(wp->w_buffer)) {
+      || prev_tick != buf_get_changedtick(wp->w_buffer)
+      || prev_vts != wp->w_buffer->b_p_vts_array) {
     prev_line = line;
     prev_ts = wp->w_buffer->b_p_ts;
     prev_tick = buf_get_changedtick(wp->w_buffer);
-    prev_indent = get_indent_str(line, (int)wp->w_buffer->b_p_ts, wp->w_p_list);
+    prev_vts = wp->w_buffer->b_p_vts_array;
+    prev_indent = get_indent_str_vtab(line,
+                                      wp->w_buffer->b_p_ts,
+                                      wp->w_buffer->b_p_vts_array,
+                                      wp->w_p_list);
   }
   bri = prev_indent + wp->w_briopt_shift;
 
diff --git a/src/nvim/message.c b/src/nvim/message.c
index 71cb345878..cdac4b602a 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -1758,7 +1758,9 @@ void msg_prt_line(char_u *s, int list)
       c = *s++;
       if (c == TAB && (!list || curwin->w_p_lcs_chars.tab1)) {
         // tab amount depends on current column
-        n_extra = curbuf->b_p_ts - col % curbuf->b_p_ts - 1;
+        n_extra = tabstop_padding(col,
+                                  curbuf->b_p_ts,
+                                  curbuf->b_p_vts_array) - 1;
         if (!list) {
           c = ' ';
           c_extra = ' ';
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 0ff427c261..ffa3e3d55f 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -333,7 +333,8 @@ static void shift_block(oparg_T *oap, int amount)
   char_u *newp;
   const int oldcol = curwin->w_cursor.col;
   const int p_sw = get_sw_value(curbuf);
-  const int p_ts = (int)curbuf->b_p_ts;
+  const long p_ts = curbuf->b_p_ts;
+  long *p_vts = curbuf->b_p_vts_array;
   struct block_def bd;
   int incr;
   int i = 0, j = 0;
@@ -383,12 +384,11 @@ static void shift_block(oparg_T *oap, int amount)
     }
     /* OK, now total=all the VWS reqd, and textstart points at the 1st
      * non-ws char in the block. */
-    if (!curbuf->b_p_et)
-      i = ((ws_vcol % p_ts) + total) / p_ts;       /* number of tabs */
-    if (i)
-      j = ((ws_vcol % p_ts) + total) % p_ts;       /* number of spp */
-    else
+    if (!curbuf->b_p_et) {
+      tabstop_fromto(ws_vcol, ws_vcol + total, p_ts, p_vts, &i, &j);
+    } else {
       j = total;
+    }
 
     // if we're splitting a TAB, allow for it
     int col_pre = bd.pre_whitesp_c - (bd.startspaces != 0);
@@ -3061,14 +3061,17 @@ void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
     if (gchar_cursor() == TAB) {
       /* Don't need to insert spaces when "p" on the last position of a
        * tab or "P" on the first position. */
+      int viscol = getviscol();
       if (dir == FORWARD
-          ? (int)curwin->w_cursor.coladd < curbuf->b_p_ts - 1
-          : curwin->w_cursor.coladd > 0)
-        coladvance_force(getviscol());
-      else
+          ? tabstop_padding(viscol, curbuf->b_p_ts, curbuf->b_p_vts_array) != 1
+          : curwin->w_cursor.coladd > 0) {
+        coladvance_force(viscol);
+      } else {
         curwin->w_cursor.coladd = 0;
-    } else if (curwin->w_cursor.coladd > 0 || gchar_cursor() == NUL)
+      }
+    } else if (curwin->w_cursor.coladd > 0 || gchar_cursor() == NUL) {
       coladvance_force(getviscol() + (dir == FORWARD));
+    }
   }
 
   lnum = curwin->w_cursor.lnum;
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 949558894f..ad4d12ff7b 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -180,6 +180,8 @@ static long p_ts;
 static long p_tw;
 static int p_udf;
 static long p_wm;
+static char_u *p_vsts;
+static char_u *p_vts;
 static char_u   *p_keymap;
 
 // Saved values for when 'bin' is set.
@@ -194,6 +196,7 @@ static int p_et_nopaste;
 static long p_sts_nopaste;
 static long p_tw_nopaste;
 static long p_wm_nopaste;
+static char_u *p_vsts_nopaste;
 
 typedef struct vimoption {
   char        *fullname;        // full option name
@@ -1998,6 +2001,8 @@ static void didset_options2(void)
 
   // Parse default for 'wildmode'.
   check_opt_wim();
+  tabstop_set(curbuf->b_p_vsts, &curbuf->b_p_vsts_array);
+  tabstop_set(curbuf->b_p_vts,  &curbuf->b_p_vts_array);
 }
 
 /// Check for string options that are NULL (normally only termcap options).
@@ -2064,6 +2069,8 @@ void check_buf_options(buf_T *buf)
   check_string_option(&buf->b_p_lw);
   check_string_option(&buf->b_p_bkc);
   check_string_option(&buf->b_p_menc);
+  check_string_option(&buf->b_p_vsts);
+  check_string_option(&buf->b_p_vts);
 }
 
 /// Free the string allocated for an option.
@@ -3110,6 +3117,69 @@ ambw_end:
     if (opt_strings_flags(p_tpf, p_tpf_values, &tpf_flags, true) != OK) {
       errmsg = e_invarg;
     }
+  } else if (varp == &(curbuf->b_p_vsts)) {  // 'varsofttabstop'
+    char_u *cp;
+
+    if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1])) {
+      if (curbuf->b_p_vsts_array) {
+        xfree(curbuf->b_p_vsts_array);
+        curbuf->b_p_vsts_array = 0;
+      }
+    } else {
+      for (cp = *varp; *cp; cp++) {
+        if (ascii_isdigit(*cp)) {
+          continue;
+        }
+        if (*cp == ',' && cp > *varp && *(cp - 1) != ',') {
+          continue;
+        }
+        errmsg = e_invarg;
+        break;
+      }
+      if (errmsg == NULL) {
+        long *oldarray = curbuf->b_p_vsts_array;
+        if (tabstop_set(*varp, &(curbuf->b_p_vsts_array))) {
+          if (oldarray) {
+            xfree(oldarray);
+          }
+        } else {
+          errmsg = e_invarg;
+        }
+      }
+    }
+  } else if (varp == &(curbuf->b_p_vts)) {  // 'vartabstop'
+    char_u *cp;
+
+    if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1])) {
+      if (curbuf->b_p_vts_array) {
+        xfree(curbuf->b_p_vts_array);
+        curbuf->b_p_vts_array = NULL;
+      }
+    } else {
+      for (cp = *varp; *cp; cp++) {
+        if (ascii_isdigit(*cp)) {
+          continue;
+        }
+        if (*cp == ',' && cp > *varp && *(cp - 1) != ',') {
+          continue;
+        }
+        errmsg = e_invarg;
+        break;
+      }
+      if (errmsg == NULL) {
+        long *oldarray = curbuf->b_p_vts_array;
+        if (tabstop_set(*varp, &(curbuf->b_p_vts_array))) {
+          if (oldarray) {
+            xfree(oldarray);
+          }
+          if (foldmethodIsIndent(curwin)) {
+            foldUpdateAll(curwin);
+          }
+        } else {
+          errmsg = e_invarg;
+        }
+      }
+    }
   } else {
     // Options that are a list of flags.
     p = NULL;
@@ -5684,6 +5754,8 @@ static char_u *get_varp(vimoption_T *p)
   case PV_TW:     return (char_u *)&(curbuf->b_p_tw);
   case PV_UDF:    return (char_u *)&(curbuf->b_p_udf);
   case PV_WM:     return (char_u *)&(curbuf->b_p_wm);
+  case PV_VSTS:   return (char_u *)&(curbuf->b_p_vsts);
+  case PV_VTS:    return (char_u *)&(curbuf->b_p_vts);
   case PV_KMAP:   return (char_u *)&(curbuf->b_p_keymap);
   case PV_SCL:    return (char_u *)&(curwin->w_p_scl);
   case PV_WINHL:  return (char_u *)&(curwin->w_p_winhl);
@@ -5935,6 +6007,15 @@ void buf_copy_options(buf_T *buf, int flags)
       buf->b_p_tfu = vim_strsave(p_tfu);
       buf->b_p_sts = p_sts;
       buf->b_p_sts_nopaste = p_sts_nopaste;
+      buf->b_p_vsts = vim_strsave(p_vsts);
+      if (p_vsts && p_vsts != empty_option) {
+        tabstop_set(p_vsts, &buf->b_p_vsts_array);
+      } else {
+        buf->b_p_vsts_array = 0;
+      }
+      buf->b_p_vsts_nopaste = p_vsts_nopaste
+                                ? vim_strsave(p_vsts_nopaste)
+                                : NULL;
       buf->b_p_com = vim_strsave(p_com);
       buf->b_p_cms = vim_strsave(p_cms);
       buf->b_p_fo = vim_strsave(p_fo);
@@ -6006,10 +6087,21 @@ void buf_copy_options(buf_T *buf, int flags)
        */
       if (dont_do_help) {
         buf->b_p_isk = save_p_isk;
+        if (p_vts && p_vts != empty_option && !buf->b_p_vts_array) {
+          tabstop_set(p_vts, &buf->b_p_vts_array);
+        } else {
+          buf->b_p_vts_array = NULL;
+        }
       } else {
         buf->b_p_isk = vim_strsave(p_isk);
         did_isk = true;
         buf->b_p_ts = p_ts;
+        buf->b_p_vts = vim_strsave(p_vts);
+        if (p_vts && p_vts != empty_option && !buf->b_p_vts_array) {
+          tabstop_set(p_vts, &buf->b_p_vts_array);
+        } else {
+          buf->b_p_vts_array = NULL;
+        }
         buf->b_help = false;
         if (buf->b_p_bt[0] == 'h') {
           clear_string_option(&buf->b_p_bt);
@@ -6624,6 +6716,12 @@ static void paste_option_changed(void)
         buf->b_p_sts_nopaste = buf->b_p_sts;
         buf->b_p_ai_nopaste = buf->b_p_ai;
         buf->b_p_et_nopaste = buf->b_p_et;
+        if (buf->b_p_vsts_nopaste) {
+          xfree(buf->b_p_vsts_nopaste);
+        }
+        buf->b_p_vsts_nopaste = buf->b_p_vsts && buf->b_p_vsts != empty_option
+                                    ? vim_strsave(buf->b_p_vsts)
+                                    : NULL;
       }
 
       // save global options
@@ -6638,6 +6736,12 @@ static void paste_option_changed(void)
       p_sts_nopaste = p_sts;
       p_tw_nopaste = p_tw;
       p_wm_nopaste = p_wm;
+      if (p_vsts_nopaste) {
+        xfree(p_vsts_nopaste);
+      }
+      p_vsts_nopaste = p_vsts && p_vsts != empty_option
+                          ? vim_strsave(p_vsts)
+                          : NULL;
     }
 
     // Always set the option values, also when 'paste' is set when it is
@@ -6649,6 +6753,14 @@ static void paste_option_changed(void)
       buf->b_p_sts = 0;             // softtabstop is 0
       buf->b_p_ai = 0;              // no auto-indent
       buf->b_p_et = 0;              // no expandtab
+      if (buf->b_p_vsts) {
+        free_string_option(buf->b_p_vsts);
+      }
+      buf->b_p_vsts = empty_option;
+      if (buf->b_p_vsts_array) {
+        xfree(buf->b_p_vsts_array);
+      }
+      buf->b_p_vsts_array = 0;
     }
 
     // set global options
@@ -6665,6 +6777,10 @@ static void paste_option_changed(void)
     p_wm = 0;
     p_sts = 0;
     p_ai = 0;
+    if (p_vsts) {
+      free_string_option(p_vsts);
+    }
+    p_vsts = empty_option;
   } else if (old_p_paste) {
     // Paste switched from on to off: Restore saved values.
 
@@ -6675,6 +6791,20 @@ static void paste_option_changed(void)
       buf->b_p_sts = buf->b_p_sts_nopaste;
       buf->b_p_ai = buf->b_p_ai_nopaste;
       buf->b_p_et = buf->b_p_et_nopaste;
+      if (buf->b_p_vsts) {
+        free_string_option(buf->b_p_vsts);
+      }
+      buf->b_p_vsts = buf->b_p_vsts_nopaste
+                        ? vim_strsave(buf->b_p_vsts_nopaste)
+                        : empty_option;
+      if (buf->b_p_vsts_array) {
+        xfree(buf->b_p_vsts_array);
+      }
+      if (buf->b_p_vsts && buf->b_p_vsts != empty_option) {
+        tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_array);
+      } else {
+        buf->b_p_vsts_array = 0;
+      }
     }
 
     // restore global options
@@ -6692,6 +6822,10 @@ static void paste_option_changed(void)
     p_sts = p_sts_nopaste;
     p_tw = p_tw_nopaste;
     p_wm = p_wm_nopaste;
+    if (p_vsts) {
+      free_string_option(p_vsts);
+    }
+    p_vsts = p_vsts_nopaste ? vim_strsave(p_vsts_nopaste) : empty_option;
   }
 
   old_p_paste = p_paste;
@@ -6941,6 +7075,265 @@ int check_ff_value(char_u *p)
   return check_opt_strings(p, p_ff_values, false);
 }
 
+// Set the integer values corresponding to the string setting of 'vartabstop'.
+// "array" will be set, caller must free it if needed.
+bool tabstop_set(char_u *var, long **array)
+{
+  long valcount = 1;
+  int t;
+  char_u *cp;
+
+  if ((!var[0] || (var[0] == '0' && !var[1]))) {
+    *array = NULL;
+    return true;
+  }
+
+  for (cp = var; *cp; cp++) {
+    if (cp == var || *(cp - 1) == ',') {
+      char_u *end;
+      if (strtol((char *)cp, (char **)&end, 10) <= 0) {
+        if (cp != end) {
+          EMSG(_(e_positive));
+        } else {
+          EMSG(_(e_invarg));
+        }
+        return false;
+      }
+    }
+
+    if (ascii_isdigit(*cp)) {
+      continue;
+    }
+    if (*cp == ',' && cp > var && *(cp - 1) != ',') {
+      valcount++;
+      continue;
+    }
+    EMSG(_(e_invarg));
+    return false;
+  }
+
+  *array = (long *)xmalloc((unsigned)(valcount + 1) * sizeof(long));
+  (*array)[0] = valcount;
+
+  t = 1;
+  for (cp = var; *cp;) {
+    (*array)[t++] = atoi((char *)cp);
+    while (*cp && *cp != ',') {
+      cp++;
+    }
+    if (*cp) {
+      cp++;
+    }
+  }
+
+  return true;
+}
+
+// Calculate the number of screen spaces a tab will occupy.
+// If "vts" is set then the tab widths are taken from that array,
+// otherwise the value of ts is used.
+int tabstop_padding(colnr_T col, long ts_arg, long *vts)
+{
+  long ts = ts_arg == 0 ? 8 : ts_arg;
+  long tabcount;
+  colnr_T tabcol = 0;
+  int t;
+  long padding = 0;
+
+  if (vts == NULL || vts[0] == 0) {
+    return (int)ts - (col % (int)ts);
+  }
+
+  tabcount = vts[0];
+
+  for (t = 1; t <= tabcount; t++) {
+    tabcol += vts[t];
+    if (tabcol > col) {
+      padding = (int)(tabcol - col);
+      break;
+    }
+  }
+  if (t > tabcount) {
+    padding = vts[tabcount] - (int)((col - tabcol) % vts[tabcount]);
+  }
+
+  return (int)padding;
+}
+
+// Find the size of the tab that covers a particular column.
+int tabstop_at(colnr_T col, long ts, long *vts)
+{
+  int tabcount;
+  colnr_T tabcol = 0;
+  int t;
+  int tab_size = 0;
+
+  if (vts == 0 || vts[0] == 0) {
+    return (int)ts;
+  }
+
+  tabcount = (int)vts[0];
+  for (t = 1; t <= tabcount; t++) {
+    tabcol += vts[t];
+    if (tabcol > col) {
+      tab_size = (int)vts[t];
+      break;
+    }
+  }
+  if (t > tabcount) {
+    tab_size = (int)vts[tabcount];
+  }
+
+  return tab_size;
+}
+
+// Find the column on which a tab starts.
+colnr_T tabstop_start(colnr_T col, long ts, long *vts)
+{
+  int tabcount;
+  colnr_T tabcol = 0;
+  int t;
+  int excess;
+
+  if (vts == 0 || vts[0] == 0) {
+    return (col / (int)ts) * (int)ts;
+  }
+
+  tabcount = (int)vts[0];
+  for (t = 1; t <= tabcount; t++) {
+    tabcol += vts[t];
+    if (tabcol > col) {
+      return tabcol - (int)vts[t];
+    }
+  }
+
+  excess = tabcol % vts[tabcount];
+  return excess + ((col - excess) / (int)vts[tabcount]) * (int)vts[tabcount];
+}
+
+// Find the number of tabs and spaces necessary to get from one column
+// to another.
+void tabstop_fromto(colnr_T start_col,
+                    colnr_T end_col,
+                    long ts,
+                    long *vts,
+                    int *ntabs,
+                    int *nspcs)
+{
+  int spaces = end_col - start_col;
+  colnr_T tabcol = 0;
+  int padding = 0;
+  int tabcount;
+  int t;
+
+  if (vts == 0 || vts[0] == 0) {
+    int tabs = 0;
+    int initspc = (int)ts - (start_col % (int)ts);
+    if (spaces >= initspc) {
+      spaces -= initspc;
+      tabs++;
+    }
+    tabs += spaces / ts;
+    spaces -= (spaces / ts) * ts;
+
+    *ntabs = tabs;
+    *nspcs = spaces;
+    return;
+  }
+
+  // Find the padding needed to reach the next tabstop.
+  tabcount = (int)vts[0];
+  for (t = 1; t <= tabcount; t++) {
+    tabcol += vts[t];
+    if (tabcol > start_col) {
+      padding = (int)(tabcol - start_col);
+      break;
+    }
+  }
+  if (t > tabcount) {
+    padding =
+      (int)vts[tabcount] - (int)((start_col - tabcol) % (int)vts[tabcount]);
+  }
+
+  // If the space needed is less than the padding no tabs can be used.
+  if (spaces < padding) {
+    *ntabs = 0;
+    *nspcs = spaces;
+    return;
+  }
+
+  *ntabs = 1;
+  spaces -= padding;
+
+  // At least one tab has been used. See if any more will fit.
+  while (spaces != 0 && ++t <= tabcount) {
+    padding = (int)vts[t];
+    if (spaces < padding) {
+      *nspcs = spaces;
+      return;
+    }
+    *ntabs += 1;
+    spaces -= padding;
+  }
+
+  *ntabs += spaces / (int)vts[tabcount];
+  *nspcs = spaces % (int)vts[tabcount];
+}
+
+// See if two tabstop arrays contain the same values.
+bool tabstop_eq(long *ts1, long *ts2)
+{
+  int t;
+
+  if ((ts1 == 0 && ts2) || (ts1 && ts2 == 0)) {
+    return false;
+  }
+  if (ts1 == ts2) {
+    return true;
+  }
+  if (ts1[0] != ts2[0]) {
+    return false;
+  }
+
+  for (t = 1; t <= ts1[0]; t++) {
+    if (ts1[t] != ts2[t]) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// Copy a tabstop array, allocating space for the new array.
+int *tabstop_copy(long *oldts)
+{
+  long *newts;
+  int t;
+
+  if (oldts == 0) {
+    return 0;
+  }
+
+  newts = xmalloc((unsigned)(oldts[0] + 1) * sizeof(long));
+  for (t = 0; t <= oldts[0]; t++) {
+    newts[t] = oldts[t];
+  }
+
+  return (int *)newts;
+}
+
+// Return a count of the number of tabstops.
+int tabstop_count(long *ts)
+{
+  return ts != NULL ? (int)ts[0] : 0;
+}
+
+// Return the first tabstop, or 8 if there are no tabstops defined.
+int tabstop_first(long *ts)
+{
+  return ts != NULL ? (int)ts[1] : 8;
+}
+
 /// Return the effective shiftwidth value for current buffer, using the
 /// 'tabstop' value when 'shiftwidth' is zero.
 int get_sw_value(buf_T *buf)
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index 43b0107800..47f0eec0b8 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -824,6 +824,8 @@ enum {
   , BV_UDF
   , BV_UL
   , BV_WM
+  , BV_VSTS
+  , BV_VTS
   , BV_COUNT        // must be the last one
 };
 
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index f4c1ac9131..d12b31bcaf 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -2999,6 +2999,23 @@ return {
       defaults={if_true={vi=4000}}
     },
     {
+      full_name='varsofttabstop', abbreviation='vsts',
+      short_desc=N_("list of numbers of spaces that <Tab> uses while editing"),
+      type='string', list='comma', scope={'buffer'},
+      vi_def=true,
+      varname='p_vsts',
+      defaults={if_true={vi=""}}
+    },
+    {
+      full_name='vartabstop', abbreviation='vts',
+      short_desc=N_("list of numbers of spaces that <Tab> in file uses"),
+      type='string', list='comma', scope={'buffer'},
+      vi_def=true,
+      varname='p_vts',
+      redraw={'current_buffer'},
+      defaults={if_true={vi=""}}
+    },
+    {
       full_name='verbose', abbreviation='vbs',
       short_desc=N_("give informative messages"),
       type='number', scope={'global'},
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 749627de80..db1c338fe9 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -3508,8 +3508,9 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
             vcol_adjusted = vcol - MB_CHARLEN(p_sbr);
           }
           // tab amount depends on current column
-          tab_len = (int)wp->w_buffer->b_p_ts
-                    - vcol_adjusted % (int)wp->w_buffer->b_p_ts - 1;
+          tab_len = tabstop_padding(vcol_adjusted,
+                                    wp->w_buffer->b_p_ts,
+                                    wp->w_buffer->b_p_vts_array) - 1;
 
           if (!wp->w_p_lbr || !wp->w_p_list) {
             n_extra = tab_len;
diff --git a/src/nvim/testdir/test_breakindent.vim b/src/nvim/testdir/test_breakindent.vim
index d53acb77d7..ff5029b889 100644
--- a/src/nvim/testdir/test_breakindent.vim
+++ b/src/nvim/testdir/test_breakindent.vim
@@ -12,56 +12,88 @@ source view_util.vim
 
 let s:input ="\tabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP"
 
-function s:screen_lines(lnum, width) abort
+func s:screen_lines(lnum, width) abort
   return ScreenLines([a:lnum, a:lnum + 2], a:width)
-endfunction
+endfunc
 
-function! s:compare_lines(expect, actual)
+func! s:compare_lines(expect, actual)
   call assert_equal(join(a:expect, "\n"), join(a:actual, "\n"))
-endfunction
+endfunc
 
-function s:test_windows(...)
+func s:test_windows(...)
   call NewWindow(10, 20)
   setl ts=4 sw=4 sts=4 breakindent
   put =s:input
   exe get(a:000, 0, '')
-endfunction
+endfunc
 
-function s:close_windows(...)
+func s:close_windows(...)
   call CloseWindow()
   exe get(a:000, 0, '')
-endfunction
+endfunc
 
-function Test_breakindent01()
+func Test_breakindent01()
   " simple breakindent test
   call s:test_windows('setl briopt=min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "    qrst",
-\ "    GHIJ",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    qrst",
+	\ "    GHIJ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent02()
+func Test_breakindent01_vartabs()
+  " like 01 but with vartabs feature
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    qrst",
+	\ "    GHIJ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent02()
   " simple breakindent test with showbreak set
   call s:test_windows('setl briopt=min:0 sbr=>>')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "    >>qr",
-\ "    >>EF",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    >>qr",
+	\ "    >>EF",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent02_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " simple breakindent test with showbreak set
+  call s:test_windows('setl briopt=min:0 sbr=>> vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    >>qr",
+	\ "    >>EF",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent03()
+func Test_breakindent03()
   " simple breakindent test with showbreak set and briopt including sbr
   call s:test_windows('setl briopt=sbr,min:0 sbr=++')
-  let lines=s:screen_lines(line('.'),8)
+  let lines = s:screen_lines(line('.'),8)
   let expect=[
 \ "    abcd",
 \ "++  qrst",
@@ -70,77 +102,177 @@ function Test_breakindent03()
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
 
-function Test_breakindent04()
+func Test_breakindent03_vartabs()
+  " simple breakindent test with showbreak set and briopt including sbr
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=sbr,min:0 sbr=++ vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "++  qrst",
+	\ "++  GHIJ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
+
+func Test_breakindent04()
   " breakindent set with min width 18
   call s:test_windows('setl sbr= briopt=min:18')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "  qrstuv",
-\ "  IJKLMN",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "  qrstuv",
+	\ "  IJKLMN",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent04_vartabs()
+  " breakindent set with min width 18
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl sbr= briopt=min:18 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "  qrstuv",
+	\ "  IJKLMN",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent05()
+func Test_breakindent05()
   " breakindent set and shift by 2
   call s:test_windows('setl briopt=shift:2,min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "      qr",
-\ "      EF",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "      qr",
+	\ "      EF",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent06()
+func Test_breakindent05_vartabs()
+  " breakindent set and shift by 2
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=shift:2,min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "      qr",
+	\ "      EF",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent06()
   " breakindent set and shift by -1
   call s:test_windows('setl briopt=shift:-1,min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "   qrstu",
-\ "   HIJKL",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "   qrstu",
+	\ "   HIJKL",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent06_vartabs()
+  " breakindent set and shift by -1
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=shift:-1,min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "   qrstu",
+	\ "   HIJKL",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent07()
+func Test_breakindent07()
   " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 cpo+=n')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "?        m",
-\ "?        x",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "?        m",
+	\ "?        x",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
+
+func Test_breakindent07_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 cpo+=n vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "?        m",
+	\ "?        x",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
 
-function Test_breakindent07a()
+func Test_breakindent07a()
   " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "    ?    m",
-\ "    ?    x",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "    ?    m",
+	\ "    ?    x",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent07a_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "    ?    m",
+	\ "    ?    x",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent08()
+func Test_breakindent08()
   " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list cpo+=n ts=4')
   " make sure, cache is invalidated!
@@ -148,43 +280,96 @@ function Test_breakindent08()
   redraw!
   set ts=4
   redraw!
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "#      opq",
-\ "#      BCD",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "#      opq",
+	\ "#      BCD",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
+
+func Test_breakindent08_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list cpo+=n ts=4 vts=4')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "#      opq",
+	\ "#      BCD",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
 
-function Test_breakindent08a()
+func Test_breakindent08a()
   " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "    #  opq",
-\ "    #  BCD",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "    #  opq",
+	\ "    #  BCD",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
 
-function Test_breakindent09()
+func Test_breakindent08a_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "    #  opq",
+	\ "    #  BCD",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
+
+func Test_breakindent09()
   " breakindent set and shift by 1, Number and list set sbr=#
   call s:test_windows('setl briopt=shift:1,min:0 nu nuw=4 sbr=# list')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "       #op",
-\ "       #AB",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "       #op",
+	\ "       #AB",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent09_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=#
+  call s:test_windows('setl briopt=shift:1,min:0 nu nuw=4 sbr=# list vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "       #op",
+	\ "       #AB",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent10()
+func Test_breakindent10()
   " breakindent set, Number set sbr=~
   call s:test_windows('setl cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0')
   " make sure, cache is invalidated!
@@ -192,41 +377,91 @@ function Test_breakindent10()
   redraw!
   set ts=4
   redraw!
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "~       mn",
-\ "~       yz",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "~       mn",
+	\ "~       yz",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
+
+func Test_breakindent10_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set, Number set sbr=~
+  call s:test_windows('setl cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0 vts=4')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "~       mn",
+	\ "~       yz",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
 
-function Test_breakindent11()
+func Test_breakindent11()
   " test strdisplaywidth()
   call s:test_windows('setl cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4')
   let text=getline(2)
   let width = strlen(text[1:])+indent(2)+strlen(&sbr)*3 " text wraps 3 times
   call assert_equal(width, strdisplaywidth(text))
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent11_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " test strdisplaywidth()
+  call s:test_windows('setl cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4 vts=4')
+  let text = getline(2)
+  let width = strlen(text[1:])+indent(2)+strlen(&sbr)*3 " text wraps 3 times
+  call assert_equal(width, strdisplaywidth(text))
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent12()
+func Test_breakindent12()
   " test breakindent with long indent
   let s:input="\t\t\t\t\t{"
   call s:test_windows('setl breakindent linebreak briopt=min:10 nu numberwidth=3 ts=4 list listchars=tab:>-')
-  let lines=s:screen_lines(2,16)
-  let expect=[
-\ " 2 >--->--->--->",
-\ "          ---{  ",
-\ "~               ",
-\ ]
+  let lines = s:screen_lines(2,16)
+  let expect = [
+	\ " 2 >--->--->--->",
+	\ "          ---{  ",
+	\ "~               ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set nuw=4 listchars=')
-endfunction
+endfunc
+
+func Test_breakindent12_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " test breakindent with long indent
+  let s:input = "\t\t\t\t\t{"
+  call s:test_windows('setl breakindent linebreak briopt=min:10 nu numberwidth=3 ts=4 list listchars=tab:>- vts=4')
+  let lines = s:screen_lines(2,16)
+  let expect = [
+	\ " 2 >--->--->--->",
+	\ "          ---{  ",
+	\ "~               ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set nuw=4 listchars= vts&')
+endfunc
 
-function Test_breakindent13()
-  let s:input=""
+func Test_breakindent13()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt=min:10 ts=8')
   vert resize 20
   call setline(1, ["    a\tb\tc\td\te", "    z   y       x       w       v"])
@@ -237,65 +472,149 @@ function Test_breakindent13()
   call assert_equal('d', @a)
   call assert_equal('w', @b)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent13_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt=min:10 ts=8 vts=8')
+  vert resize 20
+  call setline(1, ["    a\tb\tc\td\te", "    z   y       x       w       v"])
+  1
+  norm! fbgj"ayl
+  2
+  norm! fygj"byl
+  call assert_equal('d', @a)
+  call assert_equal('w', @b)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent14()
-  let s:input=""
+func Test_breakindent14()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt= ts=8')
   vert resize 30
   norm! 3a1234567890
   norm! a    abcde
   exec "norm! 0\<C-V>tex"
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "e       ",
-\ "~       ",
-\ "~       ",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "e       ",
+	\ "~       ",
+	\ "~       ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent14_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt= ts=8 vts=8')
+  vert resize 30
+  norm! 3a1234567890
+  norm! a    abcde
+  exec "norm! 0\<C-V>tex"
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "e       ",
+	\ "~       ",
+	\ "~       ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent15()
-  let s:input=""
+func Test_breakindent15()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt= ts=8 sw=8')
   vert resize 30
   norm! 4a1234567890
   exe "normal! >>\<C-V>3f0x"
-  let lines=s:screen_lines(line('.'),20)
-  let expect=[
-\ "        1234567890  ",
-\ "~                   ",
-\ "~                   ",
-\ ]
+  let lines = s:screen_lines(line('.'),20)
+  let expect = [
+	\ "        1234567890  ",
+	\ "~                   ",
+	\ "~                   ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent15_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt= ts=8 sw=8 vts=8')
+  vert resize 30
+  norm! 4a1234567890
+  exe "normal! >>\<C-V>3f0x"
+  let lines = s:screen_lines(line('.'),20)
+  let expect = [
+	\ "        1234567890  ",
+	\ "~                   ",
+	\ "~                   ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent16()
+func Test_breakindent16()
   " Check that overlong lines are indented correctly.
-  let s:input=""
+  let s:input = ""
   call s:test_windows('setl breakindent briopt=min:0 ts=4')
   call setline(1, "\t".repeat("1234567890", 10))
   resize 6
   norm! 1gg$
   redraw!
-  let lines=s:screen_lines(1,10)
-  let expect=[
-\ "    789012",
-\ "    345678",
-\ "    901234",
-\ ]
+  let lines = s:screen_lines(1,10)
+  let expect = [
+	\ "    789012",
+	\ "    345678",
+	\ "    901234",
+	\ ]
   call s:compare_lines(expect, lines)
-  let lines=s:screen_lines(4,10)
-  let expect=[
-\ "    567890",
-\ "    123456",
-\ "    7890  ",
-\ ]
+  let lines = s:screen_lines(4,10)
+  let expect = [
+	\ "    567890",
+	\ "    123456",
+	\ "    7890  ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent16_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " Check that overlong lines are indented correctly.
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt=min:0 ts=4 vts=4')
+  call setline(1, "\t".repeat("1234567890", 10))
+  resize 6
+  norm! 1gg$
+  redraw!
+  let lines = s:screen_lines(1,10)
+  let expect = [
+	\ "    789012",
+	\ "    345678",
+	\ "    901234",
+	\ ]
+  call s:compare_lines(expect, lines)
+  let lines = s:screen_lines(4,10)
+  let expect = [
+	\ "    567890",
+	\ "    123456",
+	\ "    7890  ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
 
 func Test_breakindent17_vartabs()
   if !has("vartabs")
diff --git a/src/nvim/testdir/test_vartabs.vim b/src/nvim/testdir/test_vartabs.vim
new file mode 100644
index 0000000000..85914f6bc3
--- /dev/null
+++ b/src/nvim/testdir/test_vartabs.vim
@@ -0,0 +1,257 @@
+" Test for variable tabstops
+
+if !has("vartabs")
+  finish
+endif
+
+func! Test_vartabs()
+  new
+  %d
+
+  " Test normal operation of tabstops ...
+  set ts=4
+  call setline(1, join(split('aaaaa', '\zs'), "\t"))
+  retab 8
+  let expect = "a   a\<tab>a   a\<tab>a"
+  call assert_equal(expect, getline(1))
+
+  " ... and softtabstops
+  set ts=8 sts=6
+  exe "norm! Sb\<tab>b\<tab>b\<tab>b\<tab>b"
+  let expect = "b     b\<tab>    b\<tab>  b\<tab>b"
+  call assert_equal(expect, getline(1))
+
+  " Test variable tabstops.
+  set sts=0 vts=4,8,4,8
+  exe "norm! Sc\<tab>c\<tab>c\<tab>c\<tab>c\<tab>c"
+  retab 8
+  let expect = "c   c\<tab>    c\<tab>c\<tab>c\<tab>c"
+  call assert_equal(expect, getline(1))
+
+  set et vts=4,8,4,8
+  exe "norm! Sd\<tab>d\<tab>d\<tab>d\<tab>d\<tab>d"
+  let expect = "d   d       d   d       d       d"
+  call assert_equal(expect, getline(1))
+
+  " Changing ts should have no effect if vts is in use.
+  call cursor(1, 1)
+  set ts=6
+  exe "norm! Se\<tab>e\<tab>e\<tab>e\<tab>e\<tab>e"
+  let expect = "e   e       e   e       e       e"
+  call assert_equal(expect, getline(1))
+
+  " Clearing vts should revert to using ts.
+  set vts=
+  exe "norm! Sf\<tab>f\<tab>f\<tab>f\<tab>f\<tab>f"
+  let expect = "f     f     f     f     f     f"
+  call assert_equal(expect, getline(1))
+
+  " Test variable softtabstops.
+  set noet ts=8 vsts=12,2,6
+  exe "norm! Sg\<tab>g\<tab>g\<tab>g\<tab>g\<tab>g"
+  let expect = "g\<tab>    g g\<tab>    g\<tab>  g\<tab>g"
+  call assert_equal(expect, getline(1))
+
+  " Variable tabstops and softtabstops combined.
+  set vsts=6,12,8 vts=4,6,8
+  exe "norm! Sh\<tab>h\<tab>h\<tab>h\<tab>h"
+  let expect = "h\<tab>  h\<tab>\<tab>h\<tab>h\<tab>h"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, not using vts.
+  set ts=8 sts=0 vts= vsts=
+  exe "norm! Si\<tab>i\<tab>i\<tab>i\<tab>i"
+  retab 4
+  let expect = "i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sj\<tab>j\<tab>j\<tab>j\<tab>j"
+  retab 4
+  let expect = "j\<tab>  j\<tab>\<tab>j\<tab>  j\<tab>\<tab>j"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, not using vts.
+  set ts=6 sts=0 vts= vsts=
+  exe "norm! Sk\<tab>k\<tab>k\<tab>k\<tab>k\<tab>k"
+  retab 4,8
+  let expect = "k\<tab>  k\<tab>k     k\<tab>    k\<tab>  k"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sl\<tab>l\<tab>l\<tab>l\<tab>l\<tab>l"
+  retab 4,8
+  let expect = "l\<tab>  l\<tab>l     l\<tab>    l\<tab>  l"
+  call assert_equal(expect, getline(1))
+
+  " Check that global and local values are set.
+  set ts=4 vts=6 sts=8 vsts=10
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that local values only are set.
+  setlocal ts=5 vts=7 sts=9 vsts=11
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that global values only are set.
+  setglobal ts=6 vts=8 sts=10 vsts=12
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 6)
+  call assert_equal(&vts, '8')
+  call assert_equal(&sts, 10)
+  call assert_equal(&vsts, '12')
+  bwipeout!
+
+  set ts& vts& sts& vsts& et&
+  bwipeout!
+endfunc
+
+func! Test_vartabs_breakindent()
+  if !exists("+breakindent")
+    return
+  endif
+  new
+  %d
+
+  " Test normal operation of tabstops ...
+  set ts=4
+  call setline(1, join(split('aaaaa', '\zs'), "\t"))
+  retab 8
+  let expect = "a   a\<tab>a   a\<tab>a"
+  call assert_equal(expect, getline(1))
+
+  " ... and softtabstops
+  set ts=8 sts=6
+  exe "norm! Sb\<tab>b\<tab>b\<tab>b\<tab>b"
+  let expect = "b     b\<tab>    b\<tab>  b\<tab>b"
+  call assert_equal(expect, getline(1))
+
+  " Test variable tabstops.
+  set sts=0 vts=4,8,4,8
+  exe "norm! Sc\<tab>c\<tab>c\<tab>c\<tab>c\<tab>c"
+  retab 8
+  let expect = "c   c\<tab>    c\<tab>c\<tab>c\<tab>c"
+  call assert_equal(expect, getline(1))
+
+  set et vts=4,8,4,8
+  exe "norm! Sd\<tab>d\<tab>d\<tab>d\<tab>d\<tab>d"
+  let expect = "d   d       d   d       d       d"
+  call assert_equal(expect, getline(1))
+
+  " Changing ts should have no effect if vts is in use.
+  call cursor(1, 1)
+  set ts=6
+  exe "norm! Se\<tab>e\<tab>e\<tab>e\<tab>e\<tab>e"
+  let expect = "e   e       e   e       e       e"
+  call assert_equal(expect, getline(1))
+
+  " Clearing vts should revert to using ts.
+  set vts=
+  exe "norm! Sf\<tab>f\<tab>f\<tab>f\<tab>f\<tab>f"
+  let expect = "f     f     f     f     f     f"
+  call assert_equal(expect, getline(1))
+
+  " Test variable softtabstops.
+  set noet ts=8 vsts=12,2,6
+  exe "norm! Sg\<tab>g\<tab>g\<tab>g\<tab>g\<tab>g"
+  let expect = "g\<tab>    g g\<tab>    g\<tab>  g\<tab>g"
+  call assert_equal(expect, getline(1))
+
+  " Variable tabstops and softtabstops combined.
+  set vsts=6,12,8 vts=4,6,8
+  exe "norm! Sh\<tab>h\<tab>h\<tab>h\<tab>h"
+  let expect = "h\<tab>  h\<tab>\<tab>h\<tab>h\<tab>h"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, not using vts.
+  set ts=8 sts=0 vts= vsts=
+  exe "norm! Si\<tab>i\<tab>i\<tab>i\<tab>i"
+  retab 4
+  let expect = "i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sj\<tab>j\<tab>j\<tab>j\<tab>j"
+  retab 4
+  let expect = "j\<tab>  j\<tab>\<tab>j\<tab>  j\<tab>\<tab>j"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, not using vts.
+  set ts=6 sts=0 vts= vsts=
+  exe "norm! Sk\<tab>k\<tab>k\<tab>k\<tab>k\<tab>k"
+  retab 4,8
+  let expect = "k\<tab>  k\<tab>k     k\<tab>    k\<tab>  k"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sl\<tab>l\<tab>l\<tab>l\<tab>l\<tab>l"
+  retab 4,8
+  let expect = "l\<tab>  l\<tab>l     l\<tab>    l\<tab>  l"
+  call assert_equal(expect, getline(1))
+
+  " Check that global and local values are set.
+  set ts=4 vts=6 sts=8 vsts=10
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that local values only are set.
+  setlocal ts=5 vts=7 sts=9 vsts=11
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that global values only are set.
+  setglobal ts=6 vts=8 sts=10 vsts=12
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 6)
+  call assert_equal(&vts, '8')
+  call assert_equal(&sts, 10)
+  call assert_equal(&vsts, '12')
+  bwipeout!
+
+  bwipeout!
+endfunc
diff --git a/test/functional/ex_cmds/excmd_spec.lua b/test/functional/ex_cmds/excmd_spec.lua
index aac2a9f469..33794eb50d 100644
--- a/test/functional/ex_cmds/excmd_spec.lua
+++ b/test/functional/ex_cmds/excmd_spec.lua
@@ -24,8 +24,6 @@ describe('Ex cmds', function()
       pcall_err(command, ':menu 9999999999999999999999999999999999999999'))
     eq('Vim(bdelete):E939: Positive count required',
       pcall_err(command, ':bdelete 9999999999999999999999999999999999999999'))
-    eq('Vim(retab):E487: Argument must be positive',
-      pcall_err(command, ':retab 9999999999999999999999999999999999999999'))
     assert_alive()
   end)
 end)