Repository:
https://github.com/chrisbra/vim-mq-patches
git://github.com/chrisbra/vim-mq-patches.git

Filename:
var_tabstops

Latest update for:
vim-7.4.796

Bug reports:
http://www.vim.org/maillist.php

License & Copyright:
© 2008 Matthew Winn
─────────────────────────────────────────────────────────────────────────────

Christian Brabandt 20150725
- fix offsets, fix compiler warnings (option not correctly initialized)

Christian Brabandt 20150609
- updated offsets and have the tests apply cleanly

Christian Brabandt 20141102:
- correctly cache vts values when calculating the breakindent

Christian Brabandt 20141030
[DONE] TODO: test_breakindent.out breaks, if instead of using 'ts' setting 'vts' setting is used.
[DONE] TODO: get_breakindent_win should use vts value
[DONE] TODO: get_indent_str_vtab should also use the true/false variable for checking screen size of a tab!

Roland Eggner 2014-10-23  vim-7.4.488
Fixed insertion of 4 lines after src/option.c:5439 -- due to context change in
vim-7.4.456, “hg qrefresh” inserted erroneously with fuzz 2 and -111 lines offset.
Fixed rejections of  src/testdir/Make{_{{amiga,dos,ming,os2}.mak,vms.mms},file} .

Roland Eggner 2014-09-09  vim-7.4.430
Readded  src/testdir/test_vartabs.{in,ok}  based on an older version of this patch.
Fixed rejections of  src/testdir/Make{_{{amiga,dos,ming,os2}.mak,vms.mms},file} .

diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index e2148b3..8ac07bd 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -984,6 +984,11 @@ 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().
+			If the |+vartabs| feature is enabled then 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.
 			{not in Vi}
 
 							*retab-example*
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 30ea88d..80f658c 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -6853,6 +6853,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	set.
 	NOTE: This option is set to 0 when 'compatible' is set.
 
+	If Vim is compiled with the |+vartabs| feature then 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
@@ -7402,6 +7406,10 @@ 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.
 
+	If Vim is compiled with the |+vartabs| feature then 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
@@ -8086,6 +8094,44 @@ 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
+			{only available when compiled with the |+vartabs|
+			feature}
+			{not in Vi}
+	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
+			{only available when compiled with the |+vartabs|
+			feature}
+			{not in Vi}
+	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/doc/tags b/runtime/doc/tags
index 7eaf6a0..1e068b3 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -1105,6 +1105,8 @@ $VIM_POSIX	vi_diff.txt	/*$VIM_POSIX*
 'updatetime'	options.txt	/*'updatetime'*
 'ur'	options.txt	/*'ur'*
 'ut'	options.txt	/*'ut'*
+'varsofttabstop'	options.txt	/*'varsofttabstop'*
+'vartabstop'	options.txt	/*'vartabstop'*
 'vb'	options.txt	/*'vb'*
 'vbs'	options.txt	/*'vbs'*
 'vdir'	options.txt	/*'vdir'*
@@ -1119,6 +1121,8 @@ $VIM_POSIX	vi_diff.txt	/*$VIM_POSIX*
 'virtualedit'	options.txt	/*'virtualedit'*
 'visualbell'	options.txt	/*'visualbell'*
 'vop'	options.txt	/*'vop'*
+'vsts'	options.txt	/*'vsts'*
+'vts'	options.txt	/*'vts'*
 'w1200'	vi_diff.txt	/*'w1200'*
 'w300'	vi_diff.txt	/*'w300'*
 'w9600'	vi_diff.txt	/*'w9600'*
@@ -1308,6 +1312,7 @@ $VIM_POSIX	vi_diff.txt	/*$VIM_POSIX*
 +title	various.txt	/*+title*
 +toolbar	various.txt	/*+toolbar*
 +user_commands	various.txt	/*+user_commands*
++vartabs	various.txt	/*+vartabs*
 +vertsplit	various.txt	/*+vertsplit*
 +viminfo	various.txt	/*+viminfo*
 +virtualedit	various.txt	/*+virtualedit*
diff --git a/runtime/doc/various.txt b/runtime/doc/various.txt
index 729fff5..2f68370 100644
--- a/runtime/doc/various.txt
+++ b/runtime/doc/various.txt
@@ -436,6 +436,7 @@ N  *+timers*		the |timer_start()| function
 N  *+title*		Setting the window 'title' and 'icon'
 N  *+toolbar*		|gui-toolbar|
 N  *+user_commands*	User-defined commands. |user-commands|
+B  *+vartabs*		Variable-width tabstops. |'vartabstop'|
 N  *+viminfo*		|'viminfo'|
 N  *+vertsplit*		Vertically split windows |:vsplit|
 N  *+virtualedit*	|'virtualedit'|
diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index d759c04..ae59692 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -833,6 +833,14 @@ 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/buffer.c b/src/buffer.c
index b013295..94bcb70 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2160,6 +2160,19 @@ free_buf_options(
     clear_string_option(&buf->b_p_fo);
     clear_string_option(&buf->b_p_flp);
     clear_string_option(&buf->b_p_isk);
+#ifdef FEAT_VARTABS
+    clear_string_option(&buf->b_p_vsts);
+    if (buf->b_p_vsts_nopaste)
+	vim_free(buf->b_p_vsts_nopaste);
+    buf->b_p_vsts_nopaste = 0;
+    if (buf->b_p_vsts_ary)
+	vim_free(buf->b_p_vsts_ary);
+    buf->b_p_vsts_ary = 0;
+    clear_string_option(&buf->b_p_vts);
+    if (buf->b_p_vts_ary)
+	vim_free(buf->b_p_vts_ary);
+    buf->b_p_vts_ary = 0;
+#endif
 #ifdef FEAT_KEYMAP
     clear_string_option(&buf->b_p_keymap);
     ga_clear(&buf->b_kmap_ga);
diff --git a/src/charset.c b/src/charset.c
index 134cd09..ed1f526 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -812,6 +812,15 @@ vim_strnsize(char_u *s, int len)
  * Also see getvcol() below.
  */
 
+#ifdef FEAT_VARTABS
+#define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
+    if (*(p) == TAB && (!(wp)->w_p_list || lcs_tab1)) \
+    { \
+	return tabstop_padding(col, (buf)->b_p_ts, (buf)->b_p_vts_ary); \
+    } \
+    else \
+	return ptr2cells(p);
+#else
 #define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
     if (*(p) == TAB && (!(wp)->w_p_list || lcs_tab1)) \
     { \
@@ -821,6 +830,7 @@ vim_strnsize(char_u *s, int len)
     } \
     else \
 	return ptr2cells(p);
+#endif
 
     int
 chartabsize(char_u *p, colnr_T col)
@@ -1225,8 +1235,13 @@ win_nolbr_chartabsize(
 
     if (*s == TAB && (!wp->w_p_list || lcs_tab1))
     {
+# ifdef FEAT_VARTABS
+	return tabstop_padding(col, wp->w_buffer->b_p_ts,
+				    wp->w_buffer->b_p_vts_ary);
+# else
 	n = wp->w_buffer->b_p_ts;
 	return (int)(n - (col % n));
+# endif
     }
     n = ptr2cells(s);
     /* Add one cell for a double-width character in the last column of the
@@ -1288,6 +1303,9 @@ getvcol(
     char_u	*line;		/* start of the line */
     int		incr;
     int		head;
+#ifdef FEAT_VARTABS
+    int		*vts = wp->w_buffer->b_p_vts_ary;
+#endif
     int		ts = wp->w_buffer->b_p_ts;
     int		c;
 
@@ -1327,7 +1345,11 @@ getvcol(
 	    }
 	    /* A tab gets expanded, depending on the current column */
 	    if (c == TAB)
+#ifdef FEAT_VARTABS
+		incr = tabstop_padding(vcol, ts, vts);
+#else
 		incr = ts - (vcol % ts);
+#endif
 	    else
 	    {
 #ifdef FEAT_MBYTE
diff --git a/src/edit.c b/src/edit.c
index a87c155..2d2c89a 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -716,7 +716,13 @@ edit(
 	    mincol = curwin->w_wcol;
 	    validate_cursor_col();
 
-	    if ((int)curwin->w_wcol < mincol - curbuf->b_p_ts
+	    if (
+#ifdef FEAT_VARTABS
+		(int)curwin->w_wcol < mincol
+		    - tabstop_at(get_nolist_virtcol(), curbuf->b_p_ts, curbuf->b_p_vts_ary)
+#else
+		(int)curwin->w_wcol < mincol - curbuf->b_p_ts
+#endif
 		    && curwin->w_wrow == W_WINROW(curwin)
 						 + curwin->w_height - 1 - p_so
 		    && (curwin->w_cursor.lnum != curwin->w_topline
@@ -9078,23 +9084,31 @@ ins_bs(
 	 */
 	if (	   mode == BACKSPACE_CHAR
 		&& ((p_sta && in_indent)
-		    || (get_sts_value() != 0
+		    || ((get_sts_value() != 0
+#ifdef FEAT_VARTABS
+			|| tabstop_count(curbuf->b_p_vsts_ary)
+#endif
+			)
 			&& curwin->w_cursor.col > 0
 			&& (*(ml_get_cursor() - 1) == TAB
 			    || (*(ml_get_cursor() - 1) == ' '
 				&& (!*inserted_space_p
 				    || arrow_used))))))
 	{
+#ifndef FEAT_VARTABS
 	    int		ts;
+#endif
 	    colnr_T	vcol;
 	    colnr_T	want_vcol;
 	    colnr_T	start_vcol;
 
 	    *inserted_space_p = FALSE;
+#ifndef FEAT_VARTABS
 	    if (p_sta && in_indent)
 		ts = (int)get_sw_value(curbuf);
 	    else
 		ts = (int)get_sts_value();
+#endif
 	    /* 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. */
@@ -9103,7 +9117,15 @@ ins_bs(
 	    dec_cursor();
 	    getvcol(curwin, &curwin->w_cursor, NULL, NULL, &want_vcol);
 	    inc_cursor();
+#ifdef FEAT_VARTABS
+	    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_ary);
+#else
 	    want_vcol = (want_vcol / ts) * ts;
+#endif
 
 	    /* delete characters until we are at or before want_vcol */
 	    while (vcol > want_vcol
@@ -9809,7 +9831,18 @@ ins_tab(void)
      * When nothing special, insert TAB like a normal character
      */
     if (!curbuf->b_p_et
+#ifdef FEAT_VARTABS
+	    && !(p_sta && ind
+		/* These five lines mean 'tabstop' != 'shiftwidth' */
+		&& ((tabstop_count(curbuf->b_p_vts_ary) > 1)
+		    || (tabstop_count(curbuf->b_p_vts_ary) == 1
+		        && tabstop_first(curbuf->b_p_vts_ary) != get_sw_value(curbuf))
+	            || (tabstop_count(curbuf->b_p_vts_ary) == 0
+		        && curbuf->b_p_ts != get_sw_value(curbuf))))
+	    && tabstop_count(curbuf->b_p_vsts_ary) == 0
+#else
 	    && !(p_sta && ind && curbuf->b_p_ts != get_sw_value(curbuf))
+#endif
 	    && get_sts_value() == 0)
 	return TRUE;
 
@@ -9824,6 +9857,20 @@ ins_tab(void)
 #endif
     AppendToRedobuff((char_u *)"\t");
 
+#ifdef FEAT_VARTABS
+    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_ary) > 0 || curbuf->b_p_sts > 0)
+	                        /* use 'softtabstop' when set */
+	temp = tabstop_padding(get_nolist_virtcol(), curbuf->b_p_sts,
+						     curbuf->b_p_vsts_ary);
+    else			/* otherwise use 'tabstop' */
+	temp = tabstop_padding(get_nolist_virtcol(), curbuf->b_p_ts,
+						     curbuf->b_p_vts_ary);
+#else
     if (p_sta && ind)		/* insert tab in indent, use 'shiftwidth' */
 	temp = (int)get_sw_value(curbuf);
     else if (curbuf->b_p_sts != 0) /* use 'softtabstop' when set */
@@ -9831,6 +9878,7 @@ ins_tab(void)
     else			/* otherwise use 'tabstop' */
 	temp = (int)curbuf->b_p_ts;
     temp -= get_nolist_virtcol() % temp;
+#endif
 
     /*
      * Insert the first space with ins_char().	It will delete one char in
@@ -9855,7 +9903,13 @@ ins_tab(void)
     /*
      * When 'expandtab' not set: Replace spaces by TABs where possible.
      */
+#ifdef FEAT_VARTABS
+    if (!curbuf->b_p_et && (tabstop_count(curbuf->b_p_vsts_ary) > 0
+                            || get_sts_value() > 0
+			    || (p_sta && ind)))
+#else
     if (!curbuf->b_p_et && (get_sts_value() || (p_sta && ind)))
+#endif
     {
 	char_u		*ptr;
 #ifdef FEAT_VREPLACE
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 7dd5c2a..2edd610 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -5852,6 +5852,9 @@ f_has(typval_T *argvars, typval_T *rettv)
 	"user-commands",    /* was accidentally included in 5.4 */
 	"user_commands",
 #endif
+#ifdef FEAT_VARTABS
+	"vartabs",
+#endif
 #ifdef FEAT_VIMINFO
 	"viminfo",
 #endif
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 6535de1..3221ab6 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -654,12 +654,17 @@ ex_retab(exarg_T *eap)
     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	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 */
+#ifdef FEAT_VARTABS
+    int		*new_ts = 0;
+    char_u	*new_ts_str;		/* string value of tab argument */
+#else
+    int		temp;
     int		new_ts;
+#endif
     int		save_list;
     linenr_T	first_line = 0;		/* first changed line */
     linenr_T	last_line = 0;		/* last changed line */
@@ -667,6 +672,27 @@ ex_retab(exarg_T *eap)
     save_list = curwin->w_p_list;
     curwin->w_p_list = 0;	    /* don't want list mode here */
 
+#ifdef FEAT_VARTABS
+    new_ts_str = eap->arg;
+    if (vim_isdigit(*(eap->arg)) && !tabstop_set(eap->arg, &new_ts))
+    {
+	EMSG(_(e_invarg));
+	return;
+    }
+    while (vim_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_ary;
+	new_ts_str = NULL;
+    }
+    else
+	new_ts_str = vim_strnsave(new_ts_str, eap->arg - new_ts_str);
+#else
     new_ts = getdigits(&(eap->arg));
     if (new_ts < 0)
     {
@@ -675,6 +701,7 @@ ex_retab(exarg_T *eap)
     }
     if (new_ts == 0)
 	new_ts = curbuf->b_p_ts;
+#endif
     for (lnum = eap->line1; !got_int && lnum <= eap->line2; ++lnum)
     {
 	ptr = ml_get(lnum);
@@ -707,6 +734,15 @@ ex_retab(exarg_T *eap)
 		    num_tabs = 0;
 		    if (!curbuf->b_p_et)
 		    {
+#ifdef FEAT_VARTABS
+			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;
+#else
 			temp = new_ts - (start_vcol % new_ts);
 			if (num_spaces >= temp)
 			{
@@ -715,6 +751,7 @@ ex_retab(exarg_T *eap)
 			}
 			num_tabs += num_spaces / new_ts;
 			num_spaces -= (num_spaces / new_ts) * new_ts;
+#endif
 		    }
 		    if (curbuf->b_p_et || got_tab ||
 					(num_spaces + num_tabs < len))
@@ -772,14 +809,54 @@ ex_retab(exarg_T *eap)
     if (got_int)
 	EMSG(_(e_interr));
 
+#ifdef FEAT_VARTABS
+    /* 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_ary) == 0
+	&& tabstop_count(new_ts) == 1
+	&& curbuf->b_p_ts == tabstop_first(new_ts))
+	; /* not changed */
+    else if (tabstop_count(curbuf->b_p_vts_ary) > 0
+        && tabstop_eq(curbuf->b_p_vts_ary, new_ts))
+	; /* not changed */
+    else
+	redraw_curbuf_later(NOT_VALID);
+#else
     if (curbuf->b_p_ts != new_ts)
 	redraw_curbuf_later(NOT_VALID);
+#endif
     if (first_line != 0)
 	changed_lines(first_line, 0, last_line + 1, 0L);
 
     curwin->w_p_list = save_list;	/* restore 'list' */
 
+#ifdef FEAT_VARTABS
+    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'.
+	 */
+	int* old_vts_ary = curbuf->b_p_vts_ary;
+	if (tabstop_count(old_vts_ary) > 0 || tabstop_count(new_ts) > 1) {
+	    set_string_option_direct((char_u *)"vts", -1, new_ts_str,
+						    OPT_FREE|OPT_LOCAL, 0);
+	    vim_free(new_ts_str);
+	    curbuf->b_p_vts_ary = new_ts;
+	    vim_free(old_vts_ary);
+	}
+	/* If 'vartabstop' wasn't in use and a single value was given to
+	 * retab then update 'tabstop'.
+	 */
+	else
+	{
+	    curbuf->b_p_ts = tabstop_first(new_ts);
+	    vim_free(new_ts);
+	}
+    }
+#else
     curbuf->b_p_ts = new_ts;
+#endif
     coladvance(curwin->w_curswant);
 
     u_clearline();
diff --git a/src/feature.h b/src/feature.h
index 138279e..d80ec7d 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -830,6 +830,13 @@
 #endif
 
 /*
+ * +vartabs		'vartabstop' and 'varsofttabstop' options.
+ */
+#ifdef FEAT_BIG
+# define FEAT_VARTABS
+#endif
+
+/*
  * Preferences:
  * ============
  */
diff --git a/src/gui_beval.c b/src/gui_beval.c
index 4a7c06e..314160f 100644
--- a/src/gui_beval.c
+++ b/src/gui_beval.c
@@ -241,6 +241,9 @@ gui_mch_create_beval_area(
 	beval->msg = mesg;
 	beval->msgCB = mesgCB;
 	beval->clientData = clientData;
+#ifdef FEAT_VARTABS
+	beval->vts = 0;
+#endif
 
 	/*
 	 * Set up event handler which will keep its eyes on the pointer,
@@ -283,6 +286,10 @@ gui_mch_destroy_beval_area(BalloonEval *beval)
 # else
     XtDestroyWidget(beval->balloonShell);
 # endif
+# ifdef FEAT_VARTABS
+    if (beval->vts)
+	vim_free(beval->vts);
+# endif
     vim_free(beval);
 }
 #endif
@@ -420,6 +427,11 @@ get_beval_info(
 		*lnump = lnum;
 		*textp = lbuf;
 		*colp = col;
+#ifdef FEAT_VARTABS
+		if (beval->vts)
+		    vim_free(beval->vts);
+		beval->vts = tabstop_copy(wp->w_buffer->b_p_vts_ary);
+#endif
 		beval->ts = wp->w_buffer->b_p_ts;
 		return OK;
 	    }
diff --git a/src/gui_beval.h b/src/gui_beval.h
index 4fa4c75..3f913fd 100644
--- a/src/gui_beval.h
+++ b/src/gui_beval.h
@@ -62,6 +62,9 @@ typedef struct BalloonEvalStruct
     BeState		showState;	/* tells us whats currently going on */
 # endif
 #endif
+#ifdef FEAT_VARTABS
+    int			*vts;		/* vartabstop setting for this buffer */
+#endif
     int			ts;		/* tabstop setting for this buffer */
     char_u		*msg;
     void		(*msgCB)(struct BalloonEvalStruct *, int);
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 75d600f..7178cbd 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -8892,6 +8892,9 @@ gui_mch_create_beval_area(
 	beval->msg = mesg;
 	beval->msgCB = mesgCB;
 	beval->clientData = clientData;
+#ifdef FEAT_VARTABS
+	beval->vts = 0;
+#endif
 
 	InitCommonControls();
 	cur_beval = beval;
@@ -8949,6 +8952,10 @@ TrackUserActivity(UINT uMsg)
     void
 gui_mch_destroy_beval_area(BalloonEval *beval)
 {
+#ifdef FEAT_VARTABS
+    if (beval->vts)
+	vim_free(beval->vts);
+#endif
     vim_free(beval);
 }
 #endif /* FEAT_BEVAL */
diff --git a/src/hardcopy.c b/src/hardcopy.c
index 449bfbd..d9191f3 100644
--- a/src/hardcopy.c
+++ b/src/hardcopy.c
@@ -915,7 +915,12 @@ hardcopy_line(
 	if (line[col] == TAB || tab_spaces != 0)
 	{
 	    if (tab_spaces == 0)
+#ifdef FEAT_VARTABS
+		tab_spaces = tabstop_padding(print_pos, curbuf->b_p_ts,
+							curbuf->b_p_vts_ary);
+#else
 		tab_spaces = (int)(curbuf->b_p_ts - (print_pos % curbuf->b_p_ts));
+#endif
 
 	    while (tab_spaces > 0)
 	    {
diff --git a/src/message.c b/src/message.c
index f8152a7..d0cf9da 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1702,7 +1702,11 @@ msg_prt_line(char_u *s, int list)
 	    if (c == TAB && (!list || lcs_tab1))
 	    {
 		/* tab amount depends on current column */
+#ifdef FEAT_VARTABS
+		n_extra = tabstop_padding(col, curbuf->b_p_ts, curbuf->b_p_vts_ary) - 1;
+#else
 		n_extra = curbuf->b_p_ts - col % curbuf->b_p_ts - 1;
+#endif
 		if (!list)
 		{
 		    c = ' ';
diff --git a/src/misc1.c b/src/misc1.c
index 79014cf..8d67a47 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -32,7 +32,11 @@ static garray_T	ga_users;
     int
 get_indent(void)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get_curline(), (int)curbuf->b_p_ts, curbuf->b_p_vts_ary, FALSE);
+#else
     return get_indent_str(ml_get_curline(), (int)curbuf->b_p_ts, FALSE);
+#endif
 }
 
 /*
@@ -41,7 +45,11 @@ get_indent(void)
     int
 get_indent_lnum(linenr_T lnum)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get(lnum), (int)curbuf->b_p_ts, curbuf->b_p_vts_ary, FALSE);
+#else
     return get_indent_str(ml_get(lnum), (int)curbuf->b_p_ts, FALSE);
+#endif
 }
 
 #if defined(FEAT_FOLDING) || defined(PROTO)
@@ -52,7 +60,11 @@ get_indent_lnum(linenr_T lnum)
     int
 get_indent_buf(buf_T *buf, linenr_T lnum)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get_buf(buf, lnum, FALSE), (int)curbuf->b_p_ts, buf->b_p_vts_ary, FALSE);
+#else
     return get_indent_str(ml_get_buf(buf, lnum, FALSE), (int)buf->b_p_ts, FALSE);
+#endif
 }
 #endif
 
@@ -87,6 +99,40 @@ get_indent_str(
     return count;
 }
 
+#ifdef FEAT_VARTABS
+/*
+ * count the size (in window cells) of the indent in line "ptr", using
+ * variable tabstops
+ */
+    int
+get_indent_str_vtab(ptr, ts, vts, list)
+    char_u	*ptr;
+    int		ts;
+    int		*vts;
+    int		list; /* if TRUE, count only screen size for tabs */
+{
+    int		count = 0;
+
+    for ( ; *ptr; ++ptr)
+    {
+	if (*ptr == TAB)    /* count a tab for what it is worth */
+	{
+	    if (!list || lcs_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;
+}
+#endif
+
 /*
  * Set the indent of the current line.
  * Leaves the cursor on the first non-blank in the line.
@@ -111,6 +157,9 @@ set_indent(
     int		line_len;
     int		doit = FALSE;
     int		ind_done = 0;	    /* measured in spaces */
+#ifdef FEAT_VARTABS
+    int		ind_col = 0;
+#endif
     int		tab_pad;
     int		retval = FALSE;
     int		orig_char_len = -1; /* number of initial whitespace chars when
@@ -143,8 +192,13 @@ set_indent(
 	    {
 		if (*p == TAB)
 		{
+#ifdef FEAT_VARTABS
+		    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_ary);
+#else
 		    tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		    /* stop if this tab will overshoot the target */
 		    if (todo < tab_pad)
 			break;
@@ -161,23 +215,50 @@ set_indent(
 		++p;
 	    }
 
+#ifdef FEAT_VARTABS
+	    /* These diverge from this point. */
+	    ind_col = ind_done;
+#endif
 	    /* 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 */
+#ifdef FEAT_VARTABS
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+						curbuf->b_p_vts_ary);
+#else
 	    tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	    if (todo >= tab_pad && orig_char_len == -1)
 	    {
 		doit = TRUE;
 		todo -= tab_pad;
 		++ind_len;
 		/* ind_done += tab_pad; */
+#ifdef FEAT_VARTABS
+		ind_col += tab_pad;
+#endif
 	    }
 	}
 
 	/* count tabs required for indent */
+#ifdef FEAT_VARTABS
+	for (;;)
+	{
+	    tab_pad = tabstop_padding(ind_col, curbuf->b_p_ts, curbuf->b_p_vts_ary);
+	    if (todo < tab_pad)
+		break;
+	    if (*p != TAB)
+		doit = TRUE;
+	    else
+		++p;
+	    todo -= tab_pad;
+	    ++ind_len;
+	    ind_col += tab_pad;
+	}
+#else
 	while (todo >= (int)curbuf->b_p_ts)
 	{
 	    if (*p != TAB)
@@ -188,6 +269,7 @@ set_indent(
 	    ++ind_len;
 	    /* ind_done += (int)curbuf->b_p_ts; */
 	}
+#endif
     }
     /* count spaces required for indent */
     while (todo > 0)
@@ -262,8 +344,13 @@ set_indent(
 	    {
 		if (*p == TAB)
 		{
+#ifdef FEAT_VARTABS
+		    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_ary);
+#else
 		    tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		    /* stop if this tab will overshoot the target */
 		    if (todo < tab_pad)
 			break;
@@ -279,21 +366,41 @@ set_indent(
 	    }
 
 	    /* Fill to next tabstop with a tab, if possible */
+#ifdef FEAT_VARTABS
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+						curbuf->b_p_vts_ary);
+#else
 	    tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	    if (todo >= tab_pad)
 	    {
 		*s++ = TAB;
 		todo -= tab_pad;
+#ifdef FEAT_VARTABS
+		ind_done += tab_pad;
+#endif
 	    }
 
 	    p = skipwhite(p);
 	}
 
+#ifdef FEAT_VARTABS
+	for (;;)
+	{
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts, curbuf->b_p_vts_ary);
+	    if (todo < tab_pad)
+		break;
+	    *s++ = TAB;
+	    todo -= tab_pad;
+	    ind_done += tab_pad;
+	}
+#else
 	while (todo >= (int)curbuf->b_p_ts)
 	{
 	    *s++ = TAB;
 	    todo -= (int)curbuf->b_p_ts;
 	}
+#endif
     }
     while (todo > 0)
     {
@@ -346,6 +453,9 @@ copy_indent(int size, char_u *src)
     int		tab_pad;
     int		ind_done;
     int		round;
+#ifdef FEAT_VARTABS
+    int		ind_col;
+#endif
 
     /* Round 1: compute the number of characters needed for the indent
      * Round 2: copy the characters. */
@@ -354,6 +464,9 @@ copy_indent(int size, char_u *src)
 	todo = size;
 	ind_len = 0;
 	ind_done = 0;
+#ifdef FEAT_VARTABS
+	ind_col = 0;
+#endif
 	s = src;
 
 	/* Count/copy the usable portion of the source line */
@@ -361,18 +474,28 @@ copy_indent(int size, char_u *src)
 	{
 	    if (*s == TAB)
 	    {
+#ifdef FEAT_VARTABS
+		tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts, curbuf->b_p_vts_ary);
+#else
 		tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		/* Stop if this tab will overshoot the target */
 		if (todo < tab_pad)
 		    break;
 		todo -= tab_pad;
 		ind_done += tab_pad;
+#ifdef FEAT_VARTABS
+		ind_col += tab_pad;
+#endif
 	    }
 	    else
 	    {
 		--todo;
 		++ind_done;
+#ifdef FEAT_VARTABS
+		++ind_col;
+#endif
 	    }
 	    ++ind_len;
 	    if (p != NULL)
@@ -381,22 +504,46 @@ copy_indent(int size, char_u *src)
 	}
 
 	/* Fill to next tabstop with a tab, if possible */
+#ifdef FEAT_VARTABS
+	tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts, curbuf->b_p_vts_ary);
+#else
 	tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	if (todo >= tab_pad && !curbuf->b_p_et)
 	{
 	    todo -= tab_pad;
 	    ++ind_len;
+#ifdef FEAT_VARTABS
+	    ind_col += tab_pad;
+#endif
 	    if (p != NULL)
 		*p++ = TAB;
 	}
 
 	/* Add tabs required for indent */
-	while (todo >= (int)curbuf->b_p_ts && !curbuf->b_p_et)
+	if (!curbuf->b_p_et)
 	{
-	    todo -= (int)curbuf->b_p_ts;
-	    ++ind_len;
-	    if (p != NULL)
-		*p++ = TAB;
+#ifdef FEAT_VARTABS
+	    for (;;)
+	    {
+		tab_pad = tabstop_padding(ind_col, curbuf->b_p_ts, curbuf->b_p_vts_ary);
+		if (todo < tab_pad)
+		    break;
+		todo -= tab_pad;
+		++ind_len;
+		ind_col += tab_pad;
+		if (p != NULL)
+		    *p++ = TAB;
+	    }
+#else
+	    while (todo >= (int)curbuf->b_p_ts)
+	    {
+		todo -= (int)curbuf->b_p_ts;
+		++ind_len;
+		if (p != NULL)
+		    *p++ = TAB;
+	    }
+#endif
 	}
 
 	/* Count/add spaces required for indent */
@@ -493,6 +640,7 @@ get_breakindent_win(
     static long	    prev_ts     = 0L; /* cached tabstop value */
     static char_u   *prev_line = NULL; /* cached pointer to line */
     static int	    prev_tick = 0;   /* changedtick of cached value */
+    static int      *prev_vts = 0;    /* cached vartabs values */
     int		    bri = 0;
     /* window width minus window margin space, i.e. what rests for text */
     const int	    eff_wwidth = W_WIDTH(wp)
@@ -502,13 +650,24 @@ get_breakindent_win(
 
     /* used cached indent, unless pointer or 'tabstop' changed */
     if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts
-				  || prev_tick != wp->w_buffer->b_changedtick)
+	|| prev_tick != wp->w_buffer->b_changedtick
+#ifdef FEAT_VARTABS
+	|| prev_vts != wp->w_buffer->b_p_vts_ary
+#endif
+	)
     {
 	prev_line = line;
 	prev_ts = wp->w_buffer->b_p_ts;
 	prev_tick = wp->w_buffer->b_changedtick;
+#ifdef FEAT_VARTABS
+	prev_vts = wp->w_buffer->b_p_vts_ary;
+	prev_indent = get_indent_str_vtab(line,
+				     (int)wp->w_buffer->b_p_ts,
+				     wp->w_buffer->b_p_vts_ary, wp->w_p_list);
+#else
 	prev_indent = get_indent_str(line,
 				     (int)wp->w_buffer->b_p_ts, wp->w_p_list);
+#endif
     }
     bri = prev_indent + wp->w_p_brishift;
 
@@ -734,7 +893,12 @@ open_line(
 	/*
 	 * count white space on current line
 	 */
+#ifdef FEAT_VARTABS
+	newindent = get_indent_str_vtab(saved_line, curbuf->b_p_ts,
+						    curbuf->b_p_vts_ary, FALSE);
+#else
 	newindent = get_indent_str(saved_line, (int)curbuf->b_p_ts, FALSE);
+#endif
 	if (newindent == 0 && !(flags & OPENLINE_COM_LIST))
 	    newindent = second_line_indent; /* for ^^D command in insert mode */
 
@@ -1257,7 +1421,12 @@ open_line(
 					|| do_si
 #endif
 							   )
+#ifdef FEAT_VARTABS
+			newindent = get_indent_str_vtab(leader, curbuf->b_p_ts,
+								curbuf->b_p_vts_ary, FALSE);
+#else
 			newindent = get_indent_str(leader, (int)curbuf->b_p_ts, FALSE);
+#endif
 
 		    /* Add the indent offset */
 		    if (newindent + off < 0)
diff --git a/src/ops.c b/src/ops.c
index 4bef6c5..2f02246 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -380,6 +380,9 @@ shift_block(oparg_T *oap, int amount)
     char_u		*newp, *oldp;
     int			oldcol = curwin->w_cursor.col;
     int			p_sw = (int)get_sw_value(curbuf);
+#ifdef FEAT_VARTABS
+    int			*p_vts = curbuf->b_p_vts_ary;
+#endif
     int			p_ts = (int)curbuf->b_p_ts;
     struct block_def	bd;
     int			incr;
@@ -438,12 +441,19 @@ 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. */
+#ifdef FEAT_VARTABS
+	if (!curbuf->b_p_et)
+	    tabstop_fromto(ws_vcol, ws_vcol + total, p_ts, p_vts, &i, &j);
+	else
+	    j = total;
+#else
 	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
 	    j = total;
+#endif
 	/* if we're splitting a TAB, allow for it */
 	bd.textcol -= bd.pre_whitesp_c - (bd.startspaces != 0);
 	len = (int)STRLEN(bd.textstart) + 1;
@@ -3527,10 +3537,18 @@ do_put(
 	{
 	    /* Don't need to insert spaces when "p" on the last position of a
 	     * tab or "P" on the first position. */
+#ifdef FEAT_VARTABS
+	    int viscol = getviscol();
+	    if (dir == FORWARD
+		    ? tabstop_padding(viscol, curbuf->b_p_ts, curbuf->b_p_vts_ary) != 1
+						: curwin->w_cursor.coladd > 0)
+		coladvance_force(viscol);
+#else
 	    if (dir == FORWARD
 		    ? (int)curwin->w_cursor.coladd < curbuf->b_p_ts - 1
 						: curwin->w_cursor.coladd > 0)
 		coladvance_force(getviscol());
+#endif
 	    else
 		curwin->w_cursor.coladd = 0;
 	}
diff --git a/src/option.c b/src/option.c
index 2b9ba2d..02902fc 100644
--- a/src/option.c
+++ b/src/option.c
@@ -180,6 +180,10 @@
 # define PV_UDF		OPT_BUF(BV_UDF)
 #endif
 #define PV_WM		OPT_BUF(BV_WM)
+#ifdef FEAT_VARTABS
+#define PV_VSTS		OPT_BUF(BV_VSTS)
+#define PV_VTS		OPT_BUF(BV_VTS)
+#endif
 
 /*
  * Definition of the PV_ values for window-local options.
@@ -374,6 +378,10 @@ static int	p_tx;
 static int	p_udf;
 #endif
 static long	p_wm;
+#ifdef FEAT_VARTABS
+static char_u	*p_vsts;
+static char_u	*p_vts;
+#endif
 #ifdef FEAT_KEYMAP
 static char_u	*p_keymap;
 #endif
@@ -390,6 +398,9 @@ static int	p_et_nopaste;
 static long	p_sts_nopaste;
 static long	p_tw_nopaste;
 static long	p_wm_nopaste;
+#ifdef FEAT_VARTABS
+static char_u	*p_vsts_nopaste;
+#endif
 
 struct vimoption
 {
@@ -2777,6 +2788,14 @@ static struct vimoption options[] =
     {"updatetime",  "ut",   P_NUM|P_VI_DEF,
 			    (char_u *)&p_ut, PV_NONE,
 			    {(char_u *)4000L, (char_u *)0L} SCRIPTID_INIT},
+#ifdef FEAT_VARTABS
+    {"varsofttabstop", "vsts",  P_STRING|P_VI_DEF|P_VIM|P_COMMA,
+			    (char_u *)&p_vsts, PV_VSTS,
+			    {(char_u *)"", (char_u *)0L} SCRIPTID_INIT},
+    {"vartabstop",  "vts",  P_STRING|P_VI_DEF|P_VIM|P_RBUF|P_COMMA,
+			    (char_u *)&p_vts, PV_VTS,
+			    {(char_u *)"", (char_u *)0L} SCRIPTID_INIT},
+#endif
     {"verbose",	    "vbs",  P_NUM|P_VI_DEF,
 			    (char_u *)&p_verbose, PV_NONE,
 			    {(char_u *)0L, (char_u *)0L} SCRIPTID_INIT},
@@ -5433,6 +5452,10 @@ didset_options2(void)
     /* Parse default for 'clipboard' */
     (void)check_clipboard_option();
 #endif
+#ifdef FEAT_VARTABS
+    tabstop_set(curbuf->b_p_vsts, &curbuf->b_p_vsts_ary);
+    tabstop_set(curbuf->b_p_vts,  &curbuf->b_p_vts_ary);
+#endif
 }
 
 /*
@@ -5550,6 +5573,10 @@ check_buf_options(buf_T *buf)
     check_string_option(&buf->b_p_lw);
 #endif
     check_string_option(&buf->b_p_bkc);
+#ifdef FEAT_VARTABS
+    check_string_option(&buf->b_p_vsts);
+    check_string_option(&buf->b_p_vts);
+#endif
 }
 
 /*
@@ -7258,6 +7285,88 @@ did_set_string_option(
     }
 #endif
 
+#ifdef FEAT_VARTABS
+    /* 'varsofttabstop' */
+    else if (varp == &(curbuf->b_p_vsts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vsts_ary)
+	    {
+		vim_free(curbuf->b_p_vsts_ary);
+		curbuf->b_p_vsts_ary = 0;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vsts_ary;
+		if (tabstop_set(*varp, &(curbuf->b_p_vsts_ary)))
+		{
+		    if (oldarray)
+			vim_free(oldarray);
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+
+    /* 'vartabstop' */
+    else if (varp == &(curbuf->b_p_vts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vts_ary)
+	    {
+		vim_free(curbuf->b_p_vts_ary);
+		curbuf->b_p_vts_ary = 0;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vts_ary;
+		if (tabstop_set(*varp, &(curbuf->b_p_vts_ary)))
+		{
+		    if (oldarray)
+			vim_free(oldarray);
+#ifdef FEAT_FOLDING
+		    if (foldmethodIsIndent(curwin))
+			foldUpdateAll(curwin);
+#endif /* FEAT_FOLDING */
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+#endif
+
     /* Options that are a list of flags. */
     else
     {
@@ -8525,7 +8634,14 @@ set_num_option(
     if (curbuf->b_p_sw < 0)
     {
 	errmsg = e_positive;
+#ifdef FEAT_VARTABS
+	/* Use the first 'vartabstop' value, or 'tabstop' if vts isn't in use. */
+	curbuf->b_p_sw = tabstop_count(curbuf->b_p_vts_ary) > 0
+	               ? tabstop_first(curbuf->b_p_vts_ary)
+		       : curbuf->b_p_ts;
+#else
 	curbuf->b_p_sw = curbuf->b_p_ts;
+#endif
     }
 
     /*
@@ -10496,6 +10612,10 @@ get_varp(struct vimoption *p)
 #ifdef FEAT_SIGNS
 	case PV_SCL:	return (char_u *)&(curwin->w_p_scl);
 #endif
+#ifdef FEAT_VARTABS
+	case PV_VSTS:	return (char_u *)&(curbuf->b_p_vsts);
+	case PV_VTS:	return (char_u *)&(curbuf->b_p_vts);
+#endif
 	default:	IEMSG(_("E356: get_varp ERROR"));
     }
     /* always return a valid pointer to avoid a crash! */
@@ -10816,6 +10936,15 @@ buf_copy_options(buf_T *buf, int flags)
 #endif
 	    buf->b_p_sts = p_sts;
 	    buf->b_p_sts_nopaste = p_sts_nopaste;
+#ifdef FEAT_VARTABS
+	    buf->b_p_vsts = vim_strsave(p_vsts);
+	    if (p_vsts && p_vsts != empty_option)
+		tabstop_set(p_vsts, &buf->b_p_vsts_ary);
+	    else
+		buf->b_p_vsts_ary = 0;
+	    buf->b_p_vsts_nopaste = p_vsts_nopaste
+				 ? vim_strsave(p_vsts_nopaste) : NULL;
+#endif
 	    buf->b_p_sn = p_sn;
 #ifdef FEAT_COMMENTS
 	    buf->b_p_com = vim_strsave(p_com);
@@ -10932,12 +11061,27 @@ buf_copy_options(buf_T *buf, int flags)
 	     * or to a help buffer.
 	     */
 	    if (dont_do_help)
+	    {
 		buf->b_p_isk = save_p_isk;
+#ifdef FEAT_VARTABS
+		if (p_vts && p_vts != empty_option && !buf->b_p_vts_ary)
+		    tabstop_set(p_vts, &buf->b_p_vts_ary);
+		else
+		    buf->b_p_vts_ary = 0;
+#endif
+	    }
 	    else
 	    {
 		buf->b_p_isk = vim_strsave(p_isk);
 		did_isk = TRUE;
 		buf->b_p_ts = p_ts;
+#ifdef FEAT_VARTABS
+		buf->b_p_vts = vim_strsave(p_vts);
+		if (p_vts && p_vts != empty_option && !buf->b_p_vts_ary)
+		    tabstop_set(p_vts, &buf->b_p_vts_ary);
+		else
+		    buf->b_p_vts_ary = 0;
+#endif
 		buf->b_help = FALSE;
 #ifdef FEAT_QUICKFIX
 		if (buf->b_p_bt[0] == 'h')
@@ -11760,6 +11904,12 @@ 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;
+#ifdef FEAT_VARTABS
+		if (buf->b_p_vsts_nopaste)
+		    vim_free(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;
+#endif
 	    }
 
 	    /* save global options */
@@ -11778,6 +11928,11 @@ paste_option_changed(void)
 	    p_sts_nopaste = p_sts;
 	    p_tw_nopaste = p_tw;
 	    p_wm_nopaste = p_wm;
+#ifdef FEAT_VARTABS
+	    if (p_vsts_nopaste)
+		vim_free(p_vsts_nopaste);
+	    p_vsts_nopaste = p_vsts && p_vsts != empty_option ? vim_strsave(p_vsts) : NULL;
+#endif
 	}
 
 	/*
@@ -11792,6 +11947,14 @@ 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 */
+#ifdef FEAT_VARTABS
+	    if (buf->b_p_vsts)
+		free_string_option(buf->b_p_vsts);
+	    buf->b_p_vsts = empty_option;
+	    if (buf->b_p_vsts_ary)
+		vim_free(buf->b_p_vsts_ary);
+	    buf->b_p_vsts_ary = 0;
+#endif
 	}
 
 	/* set global options */
@@ -11813,6 +11976,11 @@ paste_option_changed(void)
 	p_wm = 0;
 	p_sts = 0;
 	p_ai = 0;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = empty_option;
+#endif
     }
 
     /*
@@ -11828,6 +11996,18 @@ 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;
+#ifdef FEAT_VARTABS
+	    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_ary)
+		vim_free(buf->b_p_vsts_ary);
+	    if (buf->b_p_vsts && buf->b_p_vsts != empty_option)
+		tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_ary);
+	    else
+		buf->b_p_vsts_ary = 0;
+#endif
 	}
 
 	/* restore global options */
@@ -11850,6 +12030,11 @@ paste_option_changed(void)
 	p_sts = p_sts_nopaste;
 	p_tw = p_tw_nopaste;
 	p_wm = p_wm_nopaste;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = p_vsts_nopaste ? vim_strsave(p_vsts_nopaste) : empty_option;
+#endif
     }
 
     old_p_paste = p_paste;
@@ -12186,6 +12371,301 @@ check_ff_value(char_u *p)
     return check_opt_strings(p, p_ff_values, FALSE);
 }
 
+#ifdef FEAT_VARTABS
+
+/*
+ * Set the integer values corresponding to the string setting of 'vartabstop'.
+ */
+    int
+tabstop_set(var, array)
+    char_u	*var;
+    int		**array;
+{
+    int valcount = 1;
+    int t;
+    char_u *cp;
+
+    if ((!var[0] || (var[0] == '0' && !var[1])))
+    {
+	*array = (int *)0;
+	return TRUE;
+    }
+
+    for (cp = var; *cp; ++cp)
+    {
+	if (cp == var || *(cp - 1) == ',')
+	    if (atoi((char *)cp) <= 0)
+		return FALSE;
+
+	if (VIM_ISDIGIT(*cp))
+	    continue;
+	if (*cp == ',' && cp > var && *(cp - 1) != ',')
+	{
+	    ++valcount;
+	    continue;
+	}
+	return FALSE;
+    }
+
+    *array = (int *) alloc((unsigned) ((valcount + 1) * sizeof(int)));
+    (*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(col, ts, vts)
+    colnr_T	col;
+    int		ts;
+    int		*vts;
+{
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+    int		padding = 0;
+
+    if (ts == 0)
+	ts = 8;
+    if (vts == 0 || vts[0] == 0)
+	return ts - (col % 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 padding;
+}
+
+/*
+ * Find the size of the tab that covers a particular column.
+ */
+    int
+tabstop_at(col, ts, vts)
+    colnr_T	col;
+    int		ts;
+    int		*vts;
+{
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+    int		tab_size = 0;
+
+    if (vts == 0 || vts[0] == 0)
+	return ts;
+
+    tabcount = vts[0];
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > col)
+	{
+	    tab_size = vts[t];
+	    break;
+	}
+    }
+    if (t > tabcount)
+	tab_size = vts[tabcount];
+
+    return tab_size;
+}
+
+/*
+ * Find the column on which a tab starts.
+ */
+    colnr_T
+tabstop_start(col, ts, vts)
+    colnr_T	col;
+    int		ts;
+    int		*vts;
+{
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+
+    if (vts == 0 || vts[0] == 0)
+	return (col / ts) * ts;
+
+    tabcount = vts[0];
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > col)
+	    return tabcol - vts[t];
+    }
+
+    int excess = tabcol % vts[tabcount];
+    return excess + ((col - excess) / vts[tabcount]) * vts[tabcount];
+}
+
+/*
+ * Find the number of tabs and spaces necessary to get from one column
+ * to another.
+ */
+    void
+tabstop_fromto(start_col, end_col, ts, vts, ntabs, nspcs)
+    colnr_T	start_col;
+    colnr_T	end_col;
+    int		ts;
+    int		*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 = ts - (start_col % 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 = 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 = vts[tabcount] - (int)((start_col - tabcol) % 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 = vts[t];
+	if (spaces < padding)
+	{
+	    *nspcs = spaces;
+	    return;
+	}
+	++*ntabs;
+	spaces -= padding;
+    }
+
+    *ntabs += spaces / vts[tabcount];
+    *nspcs =  spaces % vts[tabcount];
+}
+
+/*
+ * See if two tabstop arrays contain the same values.
+ */
+    int
+tabstop_eq(ts1, ts2)
+    int		*ts1;
+    int		*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(oldts)
+    int		*oldts;
+{
+    int		*newts;
+    int		t;
+
+    if (oldts == 0)
+	return 0;
+
+    newts = (int *) alloc((unsigned) ((oldts[0] + 1) * sizeof(int)));
+    for (t = 0; t <= oldts[0]; ++t)
+	newts[t] = oldts[t];
+
+    return newts;
+}
+
+/*
+ * Return a count of the number of tabstops.
+ */
+    int
+tabstop_count(ts)
+    int		*ts;
+{
+    return ts ? ts[0] : 0;
+}
+
+/*
+ * Return the first tabstop, or 8 if there are no tabstops defined.
+ */
+    int
+tabstop_first(ts)
+    int		*ts;
+{
+    return ts ? ts[1] : 8;
+}
+
+#endif
+
 /*
  * Return the effective shiftwidth value for current buffer, using the
  * 'tabstop' value when 'shiftwidth' is zero.
diff --git a/src/option.h b/src/option.h
index 13acabf..85c9863 100644
--- a/src/option.h
+++ b/src/option.h
@@ -1102,6 +1102,10 @@ enum
     , BV_UDF
     , BV_UL
     , BV_WM
+#ifdef FEAT_VARTABS
+    , BV_VSTS
+    , BV_VTS
+#endif
     , BV_COUNT	    /* must be the last one */
 };
 
diff --git a/src/proto/misc1.pro b/src/proto/misc1.pro
index cac6449..6a2388e 100644
--- a/src/proto/misc1.pro
+++ b/src/proto/misc1.pro
@@ -3,6 +3,7 @@ int get_indent(void);
 int get_indent_lnum(linenr_T lnum);
 int get_indent_buf(buf_T *buf, linenr_T lnum);
 int get_indent_str(char_u *ptr, int ts, int list);
+int get_indent_str_vtab(char_u *ptr, int ts, int *vts, int list);
 int set_indent(int size, int flags);
 int get_number_indent(linenr_T lnum);
 int get_breakindent_win(win_T *wp, char_u *line);
diff --git a/src/proto/option.pro b/src/proto/option.pro
index 8c9bde5..7c659b3 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -59,6 +59,17 @@ int can_bs(int what);
 void save_file_ff(buf_T *buf);
 int file_ff_differs(buf_T *buf, int ignore_empty);
 int check_ff_value(char_u *p);
+#ifdef FEAT_VARTABS
+int tabstop_set(char_u *var, int **array);
+int tabstop_padding(colnr_T col, int ts, int *vts);
+colnr_T tabstop_start(colnr_T col, int ts, int *vts);
+int tabstop_at(colnr_T col, int ts, int *vts);
+void tabstop_fromto(colnr_T start_col, colnr_T end_col, int ts, int *vts, int *ntabs, int *nspcs);
+int tabstop_eq(int *ts1, int *ts2);
+int *tabstop_copy(int *oldts);
+int tabstop_count(int *ts);
+int tabstop_first(int *ts);
+#endif
 long get_sw_value(buf_T *buf);
 long get_sts_value(void);
 void find_mps_values(int *initc, int *findc, int *backwards, int switchit);
diff --git a/src/screen.c b/src/screen.c
index 4604ec7..8633071 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -4647,8 +4647,13 @@ win_line(
 			vcol_adjusted = vcol - MB_CHARLEN(p_sbr);
 #endif
 		    /* tab amount depends on current column */
+#ifdef FEAT_VARTABS
+		    tab_len = tabstop_padding(vcol_adjusted, wp->w_buffer->b_p_ts,
+						    wp->w_buffer->b_p_vts_ary) - 1;
+#else
 		    tab_len = (int)wp->w_buffer->b_p_ts
 					- vcol_adjusted % (int)wp->w_buffer->b_p_ts - 1;
+#endif
 
 #ifdef FEAT_LINEBREAK
 		    if (!wp->w_p_lbr || !wp->w_p_list)
diff --git a/src/structs.h b/src/structs.h
index 2a4284a..53c3abb 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2131,6 +2131,13 @@ 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 */
+#ifdef FEAT_VARTABS
+    char_u	*b_p_vsts;	/* 'varsofttabstop' */
+    int		*b_p_vsts_ary;	/* 'varsofttabstop' in internal format */
+    char_u	*b_p_vsts_nopaste; /* b_p_vsts saved for paste mode */
+    char_u	*b_p_vts;	/* 'vartabstop' */
+    int		*b_p_vts_ary;	/* 'vartabstop' in internal format */
+#endif
 #ifdef FEAT_KEYMAP
     char_u	*b_p_keymap;	/* 'keymap' */
 #endif
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 65ad3ee..12097e7 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -91,6 +91,8 @@ SCRIPTS_ALL = \
 	test_listlbr.out \
 	test_search_mbyte.out \
 	test_utf8.out \
+	test_vartabs.out \
+	test_vartabs_breakindent.out \
 	test_wordcount.out
 
 
diff --git a/src/version.c b/src/version.c
index 103a26f..87763ba 100644
--- a/src/version.c
+++ b/src/version.c
@@ -668,6 +668,11 @@ static char *(features[]) =
 #else
 	"-user_commands",
 #endif
+#ifdef FEAT_VARTABS
+	"+vartabs",
+#else
+	"-vartabs",
+#endif
 #ifdef FEAT_WINDOWS
 	"+vertsplit",
 #else
@@ -796,6 +801,10 @@ static int included_patches[] =
 static char *(extra_patches[]) =
 {   /* Add your patch description below this line */
 /**/
+#ifdef FEAT_VARTABS
+    "variable tabstops",
+#endif
+/**/
     NULL
 };
 
diff --git a/src/workshop.c b/src/workshop.c
index c1a3198..b2acacf 100644
--- a/src/workshop.c
+++ b/src/workshop.c
@@ -50,7 +50,11 @@ static void	 load_window(char *, int lnum);
 static void	 warp_to_pc(int);
 #ifdef FEAT_BEVAL
 void		 workshop_beval_cb(BalloonEval *, int);
+# ifdef FEAT_VARTABS
+static int	 computeIndex(int, char_u *, int, int *);
+# else
 static int	 computeIndex(int, char_u *, int);
+# endif
 #endif
 static char	*fixAccelText(char *);
 static void	 addMenu(char *, char *, char *);
@@ -1537,7 +1541,11 @@ workshop_beval_cb(
 	     * a column number. Compute the index from col. Also set
 	     * line to 0 because thats what dbx expects.
 	     */
+#ifdef FEAT_VARTABS
+	    idx = computeIndex(col, text, beval->ts, beval->vts);
+#else
 	    idx = computeIndex(col, text, beval->ts);
+#endif
 	    if (idx > 0)
 	    {
 		lnum = 0;
@@ -1572,7 +1580,11 @@ workshop_beval_cb(
 computeIndex(
 	int		 wantedCol,
 	char_u		*line,
-	int		 ts)
+	int		 ts
+#ifdef FEAT_VARTABS
+	int		*vts
+#else
+	)
 {
     int		 col = 0;
     int		 idx = 0;
@@ -1580,7 +1592,11 @@ computeIndex(
     while (line[idx])
     {
 	if (line[idx] == '\t')
+#ifdef FEAT_VARTABS
+	    col += tabstop_padding(col, ts, vts);
+#else
 	    col += ts - (col % ts);
+#endif
 	else
 	    col++;
 	idx++;