Port vim's patch 7.4.338 ('breakindent')

14 files changed, 381 insertions, 63 deletions

diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 9f5d7b86eb..4162df63ab 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -136,6 +136,10 @@ struct buffheader {
 typedef struct {
   int wo_arab;
 # define w_p_arab w_onebuf_opt.wo_arab  /* 'arabic' */
+  int wo_bri;
+# define w_p_bri w_onebuf_opt.wo_bri	/* 'breakindent' */
+  char_u *wo_briopt;
+# define w_p_briopt w_onebuf_opt.wo_briopt /* 'breakindentopt' */
   int wo_diff;
 # define w_p_diff w_onebuf_opt.wo_diff  /* 'diff' */
   long wo_fdc;
@@ -1069,6 +1073,9 @@ struct window_S {
   long_u w_p_fde_flags;             /* flags for 'foldexpr' */
   long_u w_p_fdt_flags;             /* flags for 'foldtext' */
   int         *w_p_cc_cols;         /* array of columns to highlight or NULL */
+  int         w_p_brimin;           /* minimum width for breakindent */
+  int         w_p_brishift;         /* additional shift for breakindent */
+  bool        w_p_brisbr;           /* sbr in 'briopt' */
 
   /* transform a pointer to a "onebuf" option into a "allbuf" option */
 #define GLOBAL_WO(p)    ((char *)p + sizeof(winopt_T))
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index baf6895b4c..3392cceb9f 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -13,6 +13,7 @@
 #include "nvim/charset.h"
 #include "nvim/farsi.h"
 #include "nvim/func_attr.h"
+#include "nvim/indent.h"
 #include "nvim/main.h"
 #include "nvim/mbyte.h"
 #include "nvim/memline.h"
@@ -775,9 +776,10 @@ int linetabsize(char_u *s)
 int linetabsize_col(int startcol, char_u *s)
 {
   colnr_T col = startcol;
+  char_u *line = s; /* pointer to start of line, for breakindent */
 
   while (*s != NUL) {
-    col += lbr_chartabsize_adv(&s, col);
+    col += lbr_chartabsize_adv(line, &s, col);
   }
   return (int)col;
 }
@@ -785,17 +787,17 @@ int linetabsize_col(int startcol, char_u *s)
 /// Like linetabsize(), but for a given window instead of the current one.
 ///
 /// @param wp
-/// @param p
+/// @param line
 /// @param len
 ///
 /// @return Number of characters the string will take on the screen.
-int win_linetabsize(win_T *wp, char_u *p, colnr_T len)
+int win_linetabsize(win_T *wp, char_u *line, colnr_T len)
 {
   colnr_T col = 0;
   char_u *s;
 
-  for (s = p; *s != NUL && (len == MAXCOL || s < p + len); mb_ptr_adv(s)) {
-    col += win_lbr_chartabsize(wp, s, col, NULL);
+  for (s = line; *s != NUL && (len == MAXCOL || s < line + len); mb_ptr_adv(s)) {
+    col += win_lbr_chartabsize(wp, line, s, col, NULL);
   }
   return (int)col;
 }
@@ -922,32 +924,34 @@ int vim_isprintc_strict(int c)
 
 /// like chartabsize(), but also check for line breaks on the screen
 ///
+/// @param line 
 /// @param s
 /// @param col
 ///
 /// @return The number of characters taken up on the screen.
-int lbr_chartabsize(unsigned char *s, colnr_T col)
+int lbr_chartabsize(char_u *line, unsigned char *s, colnr_T col)
 {
-  if (!curwin->w_p_lbr && (*p_sbr == NUL)) {
+  if (!curwin->w_p_lbr && (*p_sbr == NUL) && !curwin->w_p_bri) {
     if (curwin->w_p_wrap) {
       return win_nolbr_chartabsize(curwin, s, col, NULL);
     }
     RET_WIN_BUF_CHARTABSIZE(curwin, curbuf, s, col)
   }
-  return win_lbr_chartabsize(curwin, s, col, NULL);
+  return win_lbr_chartabsize(curwin, line == NULL ? s: line, s, col, NULL);
 }
 
 /// Call lbr_chartabsize() and advance the pointer.
 ///
+/// @param line
 /// @param s
 /// @param col
 ///
 /// @return The number of characters take up on the screen.
-int lbr_chartabsize_adv(char_u **s, colnr_T col)
+int lbr_chartabsize_adv(char_u *line, char_u **s, colnr_T col)
 {
   int retval;
 
-  retval = lbr_chartabsize(*s, col);
+  retval = lbr_chartabsize(line, *s, col);
   mb_ptr_adv(*s);
   return retval;
 }
@@ -959,12 +963,13 @@ int lbr_chartabsize_adv(char_u **s, colnr_T col)
 /// value, init to 0 before calling.
 ///
 /// @param wp
+/// @param line
 /// @param s
 /// @param col
 /// @param headp
 ///
 /// @return The number of characters taken up on the screen.
-int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
+int win_lbr_chartabsize(win_T *wp, char_u *line, char_u *s, colnr_T col, int *headp)
 {
   colnr_T col2;
   colnr_T colmax;
@@ -975,8 +980,8 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
   int tab_corr = (*s == TAB);
   int n;
 
-  // No 'linebreak' and 'showbreak': return quickly.
-  if (!wp->w_p_lbr && (*p_sbr == NUL)) {
+  // No 'linebreak', 'showbreak' and 'breakindent': return quickly.
+  if (!wp->w_p_lbr && !wp->w_p_bri && (*p_sbr == NUL)) {
     if (wp->w_p_wrap) {
       return win_nolbr_chartabsize(wp, s, col, headp);
     }
@@ -1039,11 +1044,12 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
     mb_added = 1;
   }
 
-  // May have to add something for 'showbreak' string at start of line
+  // May have to add something for 'breakindent' and/or 'showbreak'
+  // string at start of line.
   // Set *headp to the size of what we add.
   added = 0;
 
-  if ((*p_sbr != NUL) && wp->w_p_wrap && (col != 0)) {
+  if ((*p_sbr != NUL || wp->w_p_bri) && wp->w_p_wrap && (col != 0)) {
     numberextra = win_col_off(wp);
     col += numberextra + mb_added;
 
@@ -1056,7 +1062,12 @@ int win_lbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp)
     }
 
     if ((col == 0) || (col + size > (colnr_T)wp->w_width)) {
-      added = vim_strsize(p_sbr);
+      added = 0;
+      if (*p_sbr != NUL)
+        added += vim_strsize(p_sbr);
+      if (wp->w_p_bri)
+        added += get_breakindent_win(wp, line);
+
       if (tab_corr) {
         size += (added / wp->w_buffer->b_p_ts) * wp->w_buffer->b_p_ts;
       } else {
@@ -1157,13 +1168,14 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
   colnr_T vcol;
   char_u *ptr;    // points to current char
   char_u *posptr; // points to char at pos->col
+  char_u *line;   // start of the line
   int incr;
   int head;
   int ts = wp->w_buffer->b_p_ts;
   int c;
 
   vcol = 0;
-  ptr = ml_get_buf(wp->w_buffer, pos->lnum, FALSE);
+  line = ptr = ml_get_buf(wp->w_buffer, pos->lnum, FALSE);
 
   if (pos->col == MAXCOL) {
     // continue until the NUL
@@ -1173,11 +1185,13 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
   }
 
   // This function is used very often, do some speed optimizations.
-  // When 'list', 'linebreak' and 'showbreak' are not set use a simple loop.
-   // Also use this when 'list' is set but tabs take their normal size.
+  // When 'list', 'linebreak', 'showbreak' and 'breakindent' are not set
+  // use a simple loop.
+  // Also use this when 'list' is set but tabs take their normal size.
   if ((!wp->w_p_list || (lcs_tab1 != NUL))
       && !wp->w_p_lbr
-      && (*p_sbr == NUL)) {
+      && (*p_sbr == NUL)
+      && !wp->w_p_bri ) {
     for (;;) {
       head = 0;
       c = *ptr;
@@ -1229,7 +1243,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor,
     for (;;) {
       // A tab gets expanded, depending on the current column
       head = 0;
-      incr = win_lbr_chartabsize(wp, ptr, vcol, &head);
+      incr = win_lbr_chartabsize(wp, line, ptr, vcol, &head);
 
       // make sure we don't go past the end of the line
       if (*ptr == NUL) {
diff --git a/src/nvim/cursor.c b/src/nvim/cursor.c
index 64a3b73f15..cd84d7014c 100644
--- a/src/nvim/cursor.c
+++ b/src/nvim/cursor.c
@@ -138,7 +138,7 @@ static int coladvance2(
     ptr = line;
     while (col <= wcol && *ptr != NUL) {
       /* Count a tab for what it's worth (if list mode not on) */
-      csize = win_lbr_chartabsize(curwin, ptr, col, &head);
+      csize = win_lbr_chartabsize(curwin, line, ptr, col, &head);
       mb_ptr_adv(ptr);
       col += csize;
     }
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 93e127394b..6158176e56 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -1551,7 +1551,7 @@ change_indent (
         new_cursor_col += (*mb_ptr2len)(ptr + new_cursor_col);
       else
         ++new_cursor_col;
-      vcol += lbr_chartabsize(ptr + new_cursor_col, (colnr_T)vcol);
+      vcol += lbr_chartabsize(ptr, ptr + new_cursor_col, (colnr_T)vcol);
     }
     vcol = last_vcol;
 
@@ -5898,9 +5898,11 @@ int oneleft(void)
     width = 1;
     for (;; ) {
       coladvance(v - width);
-      /* getviscol() is slow, skip it when 'showbreak' is empty and
-       * there are no multi-byte characters */
+      /* getviscol() is slow, skip it when 'showbreak' is empty, 
+         'breakindent' is not set and there are no multi-byte 
+         characters */
       if ((*p_sbr == NUL
+           && !curwin->w_p_bri
            && !has_mbyte
            ) || getviscol() < v)
         break;
@@ -7914,10 +7916,10 @@ static int ins_tab(void)
     getvcol(curwin, &fpos, &vcol, NULL, NULL);
     getvcol(curwin, cursor, &want_vcol, NULL, NULL);
 
-    /* Use as many TABs as possible.  Beware of 'showbreak' and
-     * 'linebreak' adding extra virtual columns. */
+    /* Use as many TABs as possible.  Beware of 'breakindent', 'showbreak'
+       and 'linebreak' adding extra virtual columns. */
     while (vim_iswhite(*ptr)) {
-      i = lbr_chartabsize((char_u *)"\t", vcol);
+      i = lbr_chartabsize(NULL, (char_u *)"\t", vcol);
       if (vcol + i > want_vcol)
         break;
       if (*ptr != TAB) {
@@ -7936,10 +7938,11 @@ static int ins_tab(void)
 
     if (change_col >= 0) {
       int repl_off = 0;
+      char_u *line = ptr;
 
       /* Skip over the spaces we need. */
       while (vcol < want_vcol && *ptr == ' ') {
-        vcol += lbr_chartabsize(ptr, vcol);
+        vcol += lbr_chartabsize(line, ptr, vcol);
         ++ptr;
         ++repl_off;
       }
@@ -8126,6 +8129,7 @@ int ins_copychar(linenr_T lnum)
   int c;
   int temp;
   char_u  *ptr, *prev_ptr;
+  char_u  *line;
 
   if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count) {
     vim_beep();
@@ -8134,12 +8138,12 @@ int ins_copychar(linenr_T lnum)
 
   /* try to advance to the cursor column */
   temp = 0;
-  ptr = ml_get(lnum);
+  line = ptr = ml_get(lnum);
   prev_ptr = ptr;
   validate_virtcol();
   while ((colnr_T)temp < curwin->w_virtcol && *ptr != NUL) {
     prev_ptr = ptr;
-    temp += lbr_chartabsize_adv(&ptr, (colnr_T)temp);
+    temp += lbr_chartabsize_adv(line, &ptr, (colnr_T)temp);
   }
   if ((colnr_T)temp > curwin->w_virtcol)
     ptr = prev_ptr;
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 28048c933c..74f3edc8d9 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -1817,10 +1817,10 @@ getexmodeline (
 
         p = (char_u *)line_ga.ga_data;
         p[line_ga.ga_len] = NUL;
-        indent = get_indent_str(p, 8);
+        indent = get_indent_str(p, 8, FALSE);
         indent += sw - indent % sw;
 add_indent:
-        while (get_indent_str(p, 8) < indent) {
+        while (get_indent_str(p, 8, FALSE) < indent) {
           char_u *s = skipwhite(p);
 
           ga_grow(&line_ga, 1);
@@ -1858,11 +1858,11 @@ redraw:
           p[--line_ga.ga_len] = NUL;
         } else {
           p[line_ga.ga_len] = NUL;
-          indent = get_indent_str(p, 8);
+          indent = get_indent_str(p, 8, FALSE);
           --indent;
           indent -= indent % get_sw_value(curbuf);
         }
-        while (get_indent_str(p, 8) > indent) {
+        while (get_indent_str(p, 8, FALSE) > indent) {
           char_u *s = skipwhite(p);
 
           memmove(s - 1, s, line_ga.ga_len - (s - p) + 1);
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index e98bb2744c..6c772a8a66 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -2163,7 +2163,7 @@ static int vgetorpeek(int advance)
                 while (col < curwin->w_cursor.col) {
                   if (!vim_iswhite(ptr[col]))
                     curwin->w_wcol = vcol;
-                  vcol += lbr_chartabsize(ptr + col,
+                  vcol += lbr_chartabsize(ptr, ptr + col,
                       (colnr_T)vcol);
                   if (has_mbyte)
                     col += (*mb_ptr2len)(ptr + col);
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index d4c6b36177..7673a297f6 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -10,8 +10,10 @@
 #include "nvim/memory.h"
 #include "nvim/misc1.h"
 #include "nvim/misc2.h"
+#include "nvim/move.h"
 #include "nvim/option.h"
 #include "nvim/regexp.h"
+#include "nvim/screen.h"
 #include "nvim/search.h"
 #include "nvim/strings.h"
 #include "nvim/undo.h"
@@ -24,14 +26,14 @@
 // 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);
+  return get_indent_str(get_cursor_line_ptr(), (int)curbuf->b_p_ts, 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);
+  return get_indent_str(ml_get(lnum), (int)curbuf->b_p_ts, false);
 }
 
 
@@ -39,20 +41,27 @@ 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);
+  return get_indent_str(ml_get_buf(buf, lnum, false), (int)buf->b_p_ts, false);
 }
 
 
 // Count the size (in window cells) of the indent in line "ptr", with
 // 'tabstop' at "ts".
-int get_indent_str(char_u *ptr, int ts)
+// If @param list is TRUE, count only screen size for tabs.
+int get_indent_str(char_u *ptr, int ts, int list)
 {
   int count = 0;
 
   for (; *ptr; ++ptr) {
     // Count a tab for what it is worth.
     if (*ptr == TAB) {
-      count += ts - (count % ts);
+      if (!list || lcs_tab1) {  // count a tab for what it is worth
+        count += ts - (count % ts);
+      } else {
+        // in list mode, when tab is not set, count screen char width for Tab:
+        // ^I
+        count += ptr2cells(ptr);
+      }
     } else if (*ptr == ' ') {
       // Count a space for one.
       count++;
@@ -433,6 +442,50 @@ int get_number_indent(linenr_T lnum)
   return (int)col;
 }
 
+/*
+ * Return appropriate space number for breakindent, taking influencing
+ * parameters into account. Window must be specified, since it is not
+ * necessarily always the current one.
+ */
+int get_breakindent_win(win_T *wp, char_u *line) {
+  static int prev_indent = 0;  /* cached indent value */
+  static int prev_ts     = 0L; /* cached tabstop value */
+  static char_u *prev_line = NULL; /* cached pointer to line */
+  int bri = 0;
+  /* window width minus window margin space, i.e. what rests for text */
+  const int eff_wwidth = wp->w_width
+    - ((wp->w_p_nu || wp->w_p_rnu)
+        && (vim_strchr(p_cpo, CPO_NUMCOL) == NULL)
+        ? number_width(wp) + 1 : 0);
+
+  /* used cached indent, unless pointer or 'tabstop' changed */
+  if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts)
+  {
+    prev_line = line;
+    prev_ts = wp->w_buffer->b_p_ts;
+    prev_indent = get_indent_str(line,
+        (int)wp->w_buffer->b_p_ts, wp->w_p_list) + wp->w_p_brishift;
+  }
+
+  /* indent minus the length of the showbreak string */
+  bri = prev_indent;
+  if (wp->w_p_brisbr)
+    bri -= vim_strsize(p_sbr);
+
+  /* Add offset for number column, if 'n' is in 'cpoptions' */
+  bri += win_col_off2(wp);
+
+  /* never indent past left window margin */
+  if (bri < 0)
+    bri = 0;
+  /* always leave at least bri_min characters on the left,
+   * if text width is sufficient */
+  else if (bri > eff_wwidth - wp->w_p_brimin)
+    bri = (eff_wwidth - wp->w_p_brimin < 0)
+      ? 0 : eff_wwidth - wp->w_p_brimin;
+
+  return bri;
+}
 
 // When extra == 0: Return true if the cursor is before or on the first
 // non-blank in the line.
@@ -608,10 +661,12 @@ int get_lisp_indent(void)
       if (vi_lisp && (get_indent() == 0)) {
         amount = 2;
       } else {
+        char_u *line = that;
+
         amount = 0;
 
         while (*that && col) {
-          amount += lbr_chartabsize_adv(&that, (colnr_T)amount);
+          amount += lbr_chartabsize_adv(line, &that, (colnr_T)amount);
           col--;
         }
 
@@ -628,7 +683,7 @@ int get_lisp_indent(void)
           firsttry = amount;
 
           while (vim_iswhite(*that)) {
-            amount += lbr_chartabsize(that, (colnr_T)amount);
+            amount += lbr_chartabsize(line, that, (colnr_T)amount);
             that++;
           }
 
@@ -658,15 +713,15 @@ int get_lisp_indent(void)
                   parencount--;
                 }
                 if ((*that == '\\') && (*(that + 1) != NUL)) {
-                  amount += lbr_chartabsize_adv(&that, (colnr_T)amount);
+                  amount += lbr_chartabsize_adv(line, &that, (colnr_T)amount);
                 }
 
-                amount += lbr_chartabsize_adv(&that, (colnr_T)amount);
+                amount += lbr_chartabsize_adv(line, &that, (colnr_T)amount);
               }
             }
 
             while (vim_iswhite(*that)) {
-              amount += lbr_chartabsize(that, (colnr_T)amount);
+              amount += lbr_chartabsize(line, that, (colnr_T)amount);
               that++;
             }
 
diff --git a/src/nvim/misc1.c b/src/nvim/misc1.c
index f0c4ee492e..986374b352 100644
--- a/src/nvim/misc1.c
+++ b/src/nvim/misc1.c
@@ -194,7 +194,7 @@ open_line (
     /*
      * count white space on current line
      */
-    newindent = get_indent_str(saved_line, (int)curbuf->b_p_ts);
+    newindent = get_indent_str(saved_line, (int)curbuf->b_p_ts, FALSE);
     if (newindent == 0 && !(flags & OPENLINE_COM_LIST))
       newindent = second_line_indent;       /* for ^^D command in insert mode */
 
@@ -631,7 +631,7 @@ open_line (
         if (curbuf->b_p_ai
             || do_si
             )
-          newindent = get_indent_str(leader, (int)curbuf->b_p_ts);
+          newindent = get_indent_str(leader, (int)curbuf->b_p_ts, FALSE);
 
         /* Add the indent offset */
         if (newindent + off < 0) {
@@ -1306,6 +1306,7 @@ int plines_win_col(win_T *wp, linenr_T lnum, long column)
   char_u      *s;
   int lines = 0;
   int width;
+  char_u *line;
 
   /* Check for filler lines above this buffer line.  When folded the result
    * is one line anyway. */
@@ -1317,11 +1318,11 @@ int plines_win_col(win_T *wp, linenr_T lnum, long column)
   if (wp->w_width == 0)
     return lines + 1;
 
-  s = ml_get_buf(wp->w_buffer, lnum, FALSE);
+  line = s = ml_get_buf(wp->w_buffer, lnum, FALSE);
 
   col = 0;
   while (*s != NUL && --column >= 0) {
-    col += win_lbr_chartabsize(wp, s, (colnr_T)col, NULL);
+    col += win_lbr_chartabsize(wp, line, s, (colnr_T)col, NULL);
     mb_ptr_adv(s);
   }
 
@@ -1333,7 +1334,7 @@ int plines_win_col(win_T *wp, linenr_T lnum, long column)
    * 'ts') -- webb.
    */
   if (*s == TAB && (State & NORMAL) && (!wp->w_p_list || lcs_tab1))
-    col += win_lbr_chartabsize(wp, s, (colnr_T)col, NULL) - 1;
+    col += win_lbr_chartabsize(wp, line, s, (colnr_T)col, NULL) - 1;
 
   /*
    * Add column offset for 'number', 'relativenumber', 'foldcolumn', etc.
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 0bf338947b..0b0a913a95 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -350,7 +350,8 @@ static void shift_block(oparg_T *oap, int amount)
         ++bd.textstart;
     }
     for (; vim_iswhite(*bd.textstart); ) {
-      incr = lbr_chartabsize_adv(&bd.textstart, (colnr_T)(bd.start_vcol));
+      // TODO: is passing bd.textstart for start of the line OK?
+      incr = lbr_chartabsize_adv(bd.textstart, &bd.textstart, (colnr_T)(bd.start_vcol));
       total += incr;
       bd.start_vcol += incr;
     }
@@ -405,7 +406,7 @@ static void shift_block(oparg_T *oap, int amount)
     non_white_col = bd.start_vcol;
 
     while (vim_iswhite(*non_white)) {
-      incr = lbr_chartabsize_adv(&non_white, non_white_col);
+      incr = lbr_chartabsize_adv(bd.textstart, &non_white, non_white_col);
       non_white_col += incr;
     }
 
@@ -429,7 +430,10 @@ static void shift_block(oparg_T *oap, int amount)
     if (bd.startspaces)
       verbatim_copy_width -= bd.start_char_vcols;
     while (verbatim_copy_width < destination_col) {
-      incr = lbr_chartabsize(verbatim_copy_end, verbatim_copy_width);
+      char_u *line = verbatim_copy_end;
+
+      // TODO: is passing verbatim_copy_end for start of the line OK?
+      incr = lbr_chartabsize(line, verbatim_copy_end, verbatim_copy_width);
       if (verbatim_copy_width + incr > destination_col)
         break;
       verbatim_copy_width += incr;
@@ -2824,7 +2828,7 @@ do_put (
       oldlen = (int)STRLEN(oldp);
       for (ptr = oldp; vcol < col && *ptr; ) {
         /* Count a tab for what it's worth (if list mode not on) */
-        incr = lbr_chartabsize_adv(&ptr, (colnr_T)vcol);
+        incr = lbr_chartabsize_adv(oldp, &ptr, (colnr_T)vcol);
         vcol += incr;
       }
       bd.textcol = (colnr_T)(ptr - oldp);
@@ -2854,7 +2858,7 @@ do_put (
       /* calculate number of spaces required to fill right side of block*/
       spaces = y_width + 1;
       for (j = 0; j < yanklen; j++)
-        spaces -= lbr_chartabsize(&y_array[i][j], 0);
+        spaces -= lbr_chartabsize(NULL, &y_array[i][j], 0);
       if (spaces < 0)
         spaces = 0;
 
@@ -4114,7 +4118,7 @@ static void block_prep(oparg_T *oap, struct block_def *bdp, linenr_T lnum, int i
   prev_pstart = line;
   while (bdp->start_vcol < oap->start_vcol && *pstart) {
     /* Count a tab for what it's worth (if list mode not on) */
-    incr = lbr_chartabsize(pstart, (colnr_T)bdp->start_vcol);
+    incr = lbr_chartabsize(line, pstart, (colnr_T)bdp->start_vcol);
     bdp->start_vcol += incr;
     if (vim_iswhite(*pstart)) {
       bdp->pre_whitesp += incr;
@@ -4163,7 +4167,9 @@ static void block_prep(oparg_T *oap, struct block_def *bdp, linenr_T lnum, int i
       while (bdp->end_vcol <= oap->end_vcol && *pend != NUL) {
         /* Count a tab for what it's worth (if list mode not on) */
         prev_pend = pend;
-        incr = lbr_chartabsize_adv(&pend, (colnr_T)bdp->end_vcol);
+        // TODO: is passing prev_pend for start of the line OK?
+        // prehaps it should be "line"
+        incr = lbr_chartabsize_adv(prev_pend, &pend, (colnr_T)bdp->end_vcol);
         bdp->end_vcol += incr;
       }
       if (bdp->end_vcol <= oap->end_vcol
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 63ea2ee338..7d40fb3d6b 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -176,6 +176,8 @@
  */
 #define PV_LIST         OPT_WIN(WV_LIST)
 # define PV_ARAB        OPT_WIN(WV_ARAB)
+# define PV_BRI         OPT_WIN(WV_BRI)
+# define PV_BRIOPT      OPT_WIN(WV_BRIOPT)
 # define PV_DIFF        OPT_WIN(WV_DIFF)
 # define PV_FDC         OPT_WIN(WV_FDC)
 # define PV_FEN         OPT_WIN(WV_FEN)
@@ -471,6 +473,14 @@ static struct vimoption
    (char_u *)&p_breakat, PV_NONE,
    {(char_u *)" \t!@*-+;:,./?", (char_u *)0L}
    SCRIPTID_INIT},
+  {"breakindent",   "bri",  P_BOOL|P_VI_DEF|P_VIM|P_RWIN,
+   (char_u *)VAR_WIN, PV_BRI,
+   {(char_u *)FALSE, (char_u *)0L}
+   SCRIPTID_INIT},
+  {"breakindentopt", "briopt", P_STRING|P_ALLOCED|P_VI_DEF|P_RBUF|P_COMMA|P_NODUP,
+   (char_u *)VAR_WIN, PV_BRIOPT,
+   {(char_u *)"", (char_u *)NULL}
+   SCRIPTID_INIT},
   {"browsedir",   "bsdir",P_STRING|P_VI_DEF,
    (char_u *)NULL, PV_NONE,
    {(char_u *)0L, (char_u *)0L}
@@ -3481,6 +3491,7 @@ static void didset_options(void)
   (void)compile_cap_prog(curwin->w_s);
   /* set cedit_key */
   (void)check_cedit();
+  briopt_check();
 }
 
 /*
@@ -3815,6 +3826,11 @@ did_set_string_option (
             *p_pm == '.' ? p_pm + 1 : p_pm) == 0)
       errmsg = (char_u *)N_("E589: 'backupext' and 'patchmode' are equal");
   }
+  /* 'breakindentopt' */
+  else if (varp == &curwin->w_p_briopt) {
+    if (briopt_check() == FAIL)
+      errmsg = e_invarg;
+  }
   /*
    * 'isident', 'iskeyword', 'isprint or 'isfname' option: refill chartab[]
    * If the new option is invalid, use old value.  'lisp' option: refill
@@ -6681,6 +6697,8 @@ static char_u *get_varp(struct vimoption *p)
   case PV_SCROLL: return (char_u *)&(curwin->w_p_scr);
   case PV_WRAP:   return (char_u *)&(curwin->w_p_wrap);
   case PV_LBR:    return (char_u *)&(curwin->w_p_lbr);
+  case PV_BRI:    return (char_u *)&(curwin->w_p_bri);
+  case PV_BRIOPT: return (char_u *)&(curwin->w_p_briopt);
   case PV_SCBIND: return (char_u *)&(curwin->w_p_scb);
   case PV_CRBIND: return (char_u *)&(curwin->w_p_crb);
   case PV_COCU:    return (char_u *)&(curwin->w_p_cocu);
@@ -6788,6 +6806,8 @@ void copy_winopt(winopt_T *from, winopt_T *to)
   to->wo_wrap = from->wo_wrap;
   to->wo_wrap_save = from->wo_wrap_save;
   to->wo_lbr = from->wo_lbr;
+  to->wo_bri = from->wo_bri;
+  to->wo_briopt = vim_strsave(from->wo_briopt);
   to->wo_scb = from->wo_scb;
   to->wo_scb_save = from->wo_scb_save;
   to->wo_crb = from->wo_crb;
@@ -6842,6 +6862,7 @@ void check_winopt(winopt_T *wop)
   check_string_option(&wop->wo_stl);
   check_string_option(&wop->wo_cc);
   check_string_option(&wop->wo_cocu);
+  check_string_option(&wop->wo_briopt);
 }
 
 /*
@@ -6859,6 +6880,7 @@ void clear_winopt(winopt_T *wop)
   clear_string_option(&wop->wo_stl);
   clear_string_option(&wop->wo_cc);
   clear_string_option(&wop->wo_cocu);
+  clear_string_option(&wop->wo_briopt);
 }
 
 /*
@@ -8134,3 +8156,44 @@ void find_mps_values(int *initc, int *findc, int *backwards, int switchit)
       ++ptr;
   }
 }
+
+/* This is called when 'breakindentopt' is changed and whenn a window is
+   initialized */
+int briopt_check() {
+  char_u	*p;
+  int bri_shift = 0;
+  long bri_min = 20;
+  bool bri_sbr = false;
+
+  p = curwin->w_p_briopt;
+  while (*p != NUL)
+  {
+    if (STRNCMP(p, "shift:", 6) == 0
+        && ((p[6] == '-' && VIM_ISDIGIT(p[7])) || VIM_ISDIGIT(p[6])))
+    {
+      p += 6;
+      bri_shift = getdigits(&p);
+    }
+    else if (STRNCMP(p, "min:", 4) == 0 && VIM_ISDIGIT(p[4]))
+    {
+      p += 4;
+      bri_min = getdigits(&p);
+    }
+    else if (STRNCMP(p, "sbr", 3) == 0)
+    {
+      p += 3;
+      bri_sbr = true;
+    }
+    if (*p != ',' && *p != NUL)
+      return FAIL;
+    if (*p == ',')
+      ++p;
+  }
+
+  curwin->w_p_brishift = bri_shift;
+  curwin->w_p_brimin   = bri_min;
+  curwin->w_p_brisbr   = bri_sbr;
+
+  return OK;
+}
+
diff --git a/src/nvim/option_defs.h b/src/nvim/option_defs.h
index d862ab2761..555e9166d6 100644
--- a/src/nvim/option_defs.h
+++ b/src/nvim/option_defs.h
@@ -726,6 +726,8 @@ enum {
   , WV_COCU
   , WV_COLE
   , WV_CRBIND
+  , WV_BRI
+  , WV_BRIOPT
   , WV_DIFF
   , WV_FDC
   , WV_FEN
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 03c59bf584..61e783f2b1 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -106,6 +106,7 @@
 #include "nvim/farsi.h"
 #include "nvim/fileio.h"
 #include "nvim/fold.h"
+#include "nvim/indent.h"
 #include "nvim/getchar.h"
 #include "nvim/main.h"
 #include "nvim/mbyte.h"
@@ -2283,7 +2284,8 @@ win_line (
 # define WL_FOLD        WL_CMDLINE + 1  /* 'foldcolumn' */
 # define WL_SIGN        WL_FOLD + 1     /* column for signs */
 #define WL_NR           WL_SIGN + 1     /* line number */
-# define WL_SBR         WL_NR + 1       /* 'showbreak' or 'diff' */
+# define WL_BRI         WL_NR + 1       /* 'breakindent' */
+# define WL_SBR         WL_BRI + 1       /* 'showbreak' or 'diff' */
 #define WL_LINE         WL_SBR + 1      /* text in the line */
   int draw_state = WL_START;            /* what to draw next */
 
@@ -2540,7 +2542,7 @@ win_line (
   if (v > 0) {
     char_u  *prev_ptr = ptr;
     while (vcol < v && *ptr != NUL) {
-      c = win_lbr_chartabsize(wp, ptr, (colnr_T)vcol, NULL);
+      c = win_lbr_chartabsize(wp, line, ptr, (colnr_T)vcol, NULL);
       vcol += c;
       prev_ptr = ptr;
       mb_ptr_adv(ptr);
@@ -2817,6 +2819,34 @@ win_line (
         }
       }
 
+      if (wp->w_p_brisbr && draw_state == WL_BRI - 1
+          && n_extra == 0 && *p_sbr != NUL) {
+        // draw indent after showbreak value
+        draw_state = WL_BRI;
+      } else if (wp->w_p_brisbr && draw_state == WL_SBR && n_extra == 0) {
+        // after the showbreak, draw the breakindent
+        draw_state = WL_BRI - 1;
+      }
+
+      // draw 'breakindent': indent wrapped text accodringly
+      if (draw_state == WL_BRI - 1 && n_extra == 0) {
+        draw_state = WL_BRI;
+        if (wp->w_p_bri && n_extra == 0 && row != startrow && filler_lines == 0) {
+          char_attr = 0; // was: hl_attr(HLF_AT);
+
+          if (diff_hlf != (hlf_T)0)
+            char_attr = hl_attr(diff_hlf);
+
+          p_extra = NULL;
+          c_extra = ' ';
+          n_extra = get_breakindent_win(wp, ml_get_buf(wp->w_buffer, lnum, FALSE));
+          /* Correct end of highlighted area for 'breakindent',
+             required wen 'linebreak' is also set. */
+          if (tocol == vcol)
+            tocol += n_extra;
+        }
+      }
+
       if (draw_state == WL_SBR - 1 && n_extra == 0) {
         draw_state = WL_SBR;
         if (filler_todo > 0) {
@@ -3380,9 +3410,11 @@ win_line (
          */
         if (wp->w_p_lbr && vim_isbreak(c) && !vim_isbreak(*ptr)
             && !wp->w_p_list) {
-          n_extra = win_lbr_chartabsize(wp, ptr - (
-                has_mbyte ? mb_l :
-                1), (colnr_T)vcol, NULL) - 1;
+          char_u *p = ptr - (
+              has_mbyte ? mb_l :
+              1);
+          // TODO: is passing p for start of the line OK?
+          n_extra = win_lbr_chartabsize(wp, p, p, (colnr_T)vcol, NULL) - 1;
           c_extra = ' ';
           if (vim_iswhite(c)) {
             if (c == TAB)
diff --git a/src/nvim/testdir/test_breakindent.in b/src/nvim/testdir/test_breakindent.in
new file mode 100644
index 0000000000..8f40e4f7e5
--- /dev/null
+++ b/src/nvim/testdir/test_breakindent.in
@@ -0,0 +1,79 @@
+Test for breakindent
+
+STARTTEST
+:so small.vim
+:if !exists("+breakindent") | e! test.ok | w! test.out | qa! | endif
+:10new|:vsp|:vert resize 20
+:put =\"\tabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP\"
+:set ts=4 sw=4 sts=4 breakindent
+:fu! ScreenChar(width)
+:	let c=''
+:	for i in range(1,a:width)
+:		let c.=nr2char(screenchar(line('.'), i))
+:	endfor
+:       let c.="\n"
+:	for i in range(1,a:width)
+:		let c.=nr2char(screenchar(line('.')+1, i))
+:	endfor
+:       let c.="\n"
+:	for i in range(1,a:width)
+:		let c.=nr2char(screenchar(line('.')+2, i))
+:	endfor
+:	return c
+:endfu
+:fu DoRecordScreen()
+:	wincmd l
+:	$put =printf(\"\n%s\", g:test)
+:	$put =g:line1
+:	wincmd p
+:endfu
+:let g:test="Test 1: Simple breakindent"
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test="Test 2: Simple breakindent + sbr=>>"
+:set sbr=>>
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test ="Test 3: Simple breakindent + briopt:sbr"
+:set briopt=sbr,min:0 sbr=++
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test ="Test 4: Simple breakindent + min width: 18"
+:set sbr= briopt=min:18
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test =" Test 5: Simple breakindent + shift by 2"
+:set briopt=shift:2,min:0
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test=" Test 6: Simple breakindent + shift by -1"
+:set briopt=shift:-1,min:0
+:let line1=ScreenChar(8)
+:call DoRecordScreen()
+:let g:test=" Test 7: breakindent + shift by +1 + nu + sbr=? briopt:sbr"
+:set briopt=shift:1,sbr,min:0 nu sbr=? nuw=4
+:let line1=ScreenChar(10)
+:call DoRecordScreen()
+:let g:test=" Test 8: breakindent + shift:1 + nu + sbr=# list briopt:sbr"
+:set briopt=shift:1,sbr,min:0 nu sbr=# list
+:let line1=ScreenChar(10)
+:call DoRecordScreen()
+:let g:test=" Test 9: breakindent + shift by +1 + 'nu' + sbr=# list"
+:set briopt-=sbr
+:let line1=ScreenChar(10)
+:call DoRecordScreen()
+:let g:test=" Test 10: breakindent + shift by +1 + 'nu' + sbr=~ cpo+=n"
+:set cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0
+:let line1=ScreenChar(10)
+:call DoRecordScreen()
+:wincmd p
+:let g:test="\n Test 11: strdisplaywidth when breakindent is on"
+:set cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4
+:let text=getline(2) "skip leading tab when calculating text width
+:let width = strlen(text[1:])+indent(2)*4+strlen(&sbr)*3 " text wraps 3 times
+:$put =g:test
+:$put =printf(\"strdisplaywidth: %d == calculated: %d\", strdisplaywidth(text), width)
+:%w! test.out
+:qa!
+ENDTEST
+dummy text
diff --git a/src/nvim/testdir/test_breakindent.ok b/src/nvim/testdir/test_breakindent.ok
new file mode 100644
index 0000000000..723cb25012
--- /dev/null
+++ b/src/nvim/testdir/test_breakindent.ok
@@ -0,0 +1,55 @@
+
+	abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP
+
+Test 1: Simple breakindent
+    abcd
+    qrst
+    GHIJ
+
+Test 2: Simple breakindent + sbr=>>
+    abcd
+    >>qr
+    >>EF
+
+Test 3: Simple breakindent + briopt:sbr
+    abcd
+++  qrst
+++  GHIJ
+
+Test 4: Simple breakindent + min width: 18
+    abcd
+  qrstuv
+  IJKLMN
+
+ Test 5: Simple breakindent + shift by 2
+    abcd
+      qr
+      EF
+
+ Test 6: Simple breakindent + shift by -1
+    abcd
+   qrstu
+   HIJKL
+
+ Test 7: breakindent + shift by +1 + nu + sbr=? briopt:sbr
+  2     ab
+?        m
+?        x
+
+ Test 8: breakindent + shift:1 + nu + sbr=# list briopt:sbr
+  2 ^Iabcd
+#      opq
+#      BCD
+
+ Test 9: breakindent + shift by +1 + 'nu' + sbr=# list
+  2 ^Iabcd
+       #op
+       #AB
+
+ Test 10: breakindent + shift by +1 + 'nu' + sbr=~ cpo+=n
+  2     ab
+~       mn
+~       yz
+
+ Test 11: strdisplaywidth when breakindent is on
+strdisplaywidth: 46 == calculated: 64