vim-patch:8.2.3160: 'breakindent' does not work well for bulleted lists

Problem:    'breakindent' does not work well for bulleted and numbered lists.
Solution:   Add the "list" entry to 'breakindentopt'. (Christian Brabandt,
            closes vim/vim#8564, closes vim/vim#1661)
4a0b85ad01

runtime/doc/options.txt

@@ -1038,7 +1038,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 			    continuation (positive).
 		sbr	    Display the 'showbreak' value before applying the
 			    additional indent.
-	The default value for min is 20 and shift is 0.
+		list:{n}    Adds an additional indent for lines that match a 
+			    numbered or bulleted list (using the
+			    'formatlistpat' setting).
+	The default value for min is 20, shift and list is 0.
 
 						*'browsedir'* *'bsdir'*
 'browsedir' 'bsdir'	string	(default: "last")

src/nvim/buffer_defs.h

@@ -1395,6 +1395,7 @@ struct window_S {
   int w_briopt_min;                 // minimum width for breakindent
   int w_briopt_shift;               // additional shift for breakindent
   bool w_briopt_sbr;                // sbr in 'briopt'
+  int w_briopt_list;                // additional indent for lists
 
   // transform a pointer to a "onebuf" option into a "allbuf" option
 #define GLOBAL_WO(p)    ((char *)p + sizeof(winopt_T))

src/nvim/indent.c

@@ -432,7 +432,7 @@ int get_number_indent(linenr_T lnum)
 // 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, const char_u *line)
+int get_breakindent_win(win_T *wp, char_u *line)
   FUNC_ATTR_NONNULL_ALL
 {
   static int prev_indent = 0;  // Cached indent value.
@@ -469,6 +469,22 @@ int get_breakindent_win(win_T *wp, const char_u *line)
   // Add offset for number column, if 'n' is in 'cpoptions'
   bri += win_col_off2(wp);
 
+  // add additional indent for numbered lists
+  if (wp->w_briopt_list > 0) {
+    regmatch_T regmatch = {
+      .regprog = vim_regcomp(curbuf->b_p_flp,
+                             RE_MAGIC + RE_STRING + RE_AUTO + RE_STRICT),
+    };
+
+    if (regmatch.regprog != NULL) {
+      if (vim_regexec(&regmatch, line, 0)) {
+        bri += wp->w_briopt_list;
+      }
+      vim_regfree(regmatch.regprog);
+    }
+  }
+
+
   // never indent past left window margin
   if (bri < 0) {
     bri = 0;

src/nvim/option.c

@@ -7426,6 +7426,7 @@ static bool briopt_check(win_T *wp)
   int bri_shift = 0;
   int bri_min = 20;
   bool bri_sbr = false;
+  int bri_list = 0;
 
   char_u *p = wp->w_p_briopt;
   while (*p != NUL)
@@ -7445,6 +7446,9 @@ static bool briopt_check(win_T *wp)
     {
       p += 3;
       bri_sbr = true;
+    } else if (STRNCMP(p, "list:", 5) == 0) {
+      p += 5;
+      bri_list = (int)getdigits(&p, false, 0);
     }
     if (*p != ',' && *p != NUL) {
       return false;
@@ -7457,6 +7461,7 @@ static bool briopt_check(win_T *wp)
   wp->w_briopt_shift = bri_shift;
   wp->w_briopt_min = bri_min;
   wp->w_briopt_sbr = bri_sbr;
+  wp->w_briopt_list  = bri_list;
 
   return true;
 }

src/nvim/testdir/test_breakindent.vim

@@ -16,6 +16,10 @@ func s:screen_lines(lnum, width) abort
   return ScreenLines([a:lnum, a:lnum + 2], a:width)
 endfunc
 
+func s:screen_lines2(lnums, lnume, width) abort
+  return ScreenLines([a:lnums, a:lnume], a:width)
+endfunc
+
 func! s:compare_lines(expect, actual)
   call assert_equal(join(a:expect, "\n"), join(a:actual, "\n"))
 endfunc
@@ -745,4 +749,70 @@ func Test_breakindent20_cpo_n_nextpage()
   call s:close_windows('set breakindent& briopt& cpo& number&')
 endfunc
 
+func Test_breakindent20_list()
+  call s:test_windows('setl breakindent breakindentopt= linebreak')
+  " default:
+  call setline(1, ['  1.  Congress shall make no law',
+        \ '  2.) Congress shall make no law',
+        \ '  3.] Congress shall make no law'])
+  norm! 1gg
+  redraw!
+  let lines = s:screen_lines2(1, 6, 20)
+  let expect = [
+	\ "  1.  Congress      ",
+	\ "shall make no law   ",
+	\ "  2.) Congress      ",
+	\ "shall make no law   ",
+	\ "  3.] Congress      ",
+	\ "shall make no law   ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " set mininum indent
+  setl briopt=min:5
+  redraw!
+  let lines = s:screen_lines2(1, 6, 20)
+  let expect = [
+	\ "  1.  Congress      ",
+	\ "  shall make no law ",
+	\ "  2.) Congress      ",
+	\ "  shall make no law ",
+	\ "  3.] Congress      ",
+	\ "  shall make no law ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " set additional handing indent
+  setl briopt+=list:4
+  redraw!
+  let expect = [
+	\ "  1.  Congress      ",
+	\ "      shall make no ",
+	\ "      law           ",
+	\ "  2.) Congress      ",
+	\ "      shall make no ",
+	\ "      law           ",
+	\ "  3.] Congress      ",
+	\ "      shall make no ",
+	\ "      law           ",
+	\ ]
+  let lines = s:screen_lines2(1, 9, 20)
+  call s:compare_lines(expect, lines)
+  " reset linebreak option
+  " Note: it indents by one additional
+  " space, because of the leading space.
+  setl linebreak&vim list listchars=eol:$,space:_
+  redraw!
+  let expect = [
+	\ "__1.__Congress_shall",
+	\ "      _make_no_law$ ",
+	\ "__2.)_Congress_shall",
+	\ "      _make_no_law$ ",
+	\ "__3.]_Congress_shall",
+	\ "      _make_no_law$ ",
+	\ ]
+  let lines = s:screen_lines2(1, 6, 20)
+  call s:compare_lines(expect, lines)
+
+  call s:close_windows('set breakindent& briopt& linebreak& list& listchars&')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab