patch 8.2.4882: cannot make 'breakindent' use a specific column

Problem:    Cannot make 'breakindent' use a specific column.
Solution:   Add the "column" entry in 'breakindentopt'. (Christian Brabandt,
            closes #10362, closes #10325)

runtime/doc/options.txt

@@ -1392,14 +1392,20 @@ A jump table for the options with a short description can be found at |Q_op|.
 			    characters.  It permits dynamic French paragraph
 			    indentation (negative) or emphasizing the line
 			    continuation (positive).
+			    (default: 0)
 		sbr	    Display the 'showbreak' value before applying the
 			    additional indent.
+			    (default: off)
 		list:{n}    Adds an additional indent for lines that match a
 			    numbered or bulleted list (using the
 			    'formatlistpat' setting).
 		list:-1	    Uses the length of a match with 'formatlistpat'
 			    for indentation.
-	The default value for min is 20, shift and list is 0.
+			    (default: 0)
+		column:{n}  Indent at column {n}. Will overrule the other
+			    sub-options. Note: an additional indent may be
+			    added for the 'showbreak' setting.
+			    (default: off)
 
 						*'browsedir'* *'bsdir'*
 'browsedir' 'bsdir'	string	(default: "last")

src/indent.c

@@ -866,6 +866,7 @@ briopt_check(win_T *wp)
     long	bri_min = 20;
     int		bri_sbr = FALSE;
     int		bri_list = 0;
+    int		bri_vcol = 0;
 
     p = wp->w_p_briopt;
     while (*p != NUL)
@@ -891,6 +892,11 @@ briopt_check(win_T *wp)
 	    p += 5;
 	    bri_list = getdigits(&p);
 	}
+	else if (STRNCMP(p, "column:", 7) == 0)
+	{
+	    p += 7;
+	    bri_vcol = getdigits(&p);
+	}
 	if (*p != ',' && *p != NUL)
 	    return FAIL;
 	if (*p == ',')
@@ -901,6 +907,7 @@ briopt_check(win_T *wp)
     wp->w_briopt_min   = bri_min;
     wp->w_briopt_sbr   = bri_sbr;
     wp->w_briopt_list  = bri_list;
+    wp->w_briopt_vcol  = bri_vcol;
 
     return OK;
 }
@@ -953,10 +960,12 @@ get_breakindent_win(
 	prev_tick = CHANGEDTICK(wp->w_buffer);
 # ifdef FEAT_VARTABS
 	prev_vts = wp->w_buffer->b_p_vts_array;
+	if (wp->w_briopt_vcol == 0)
 	    prev_indent = get_indent_str_vtab(line,
 				     (int)wp->w_buffer->b_p_ts,
 				    wp->w_buffer->b_p_vts_array, wp->w_p_list);
 # else
+	if (wp->w_briopt_vcol == 0)
 	    prev_indent = get_indent_str(line,
 				     (int)wp->w_buffer->b_p_ts, wp->w_p_list);
 # endif
@@ -965,7 +974,7 @@ get_breakindent_win(
 	vim_free(prev_flp);
 	prev_flp = vim_strsave(get_flp_value(wp->w_buffer));
 	// add additional indent for numbered lists
-	if (wp->w_briopt_list != 0)
+	if (wp->w_briopt_list != 0 && wp->w_briopt_vcol == 0)
 	{
 	    regmatch_T	    regmatch;
 
@@ -986,6 +995,13 @@ get_breakindent_win(
 	    }
 	}
     }
+    if (wp->w_briopt_vcol != 0)
+    {
+	// column value has priority
+	bri = wp->w_briopt_vcol;
+	prev_list = 0;
+    }
+    else
 	bri = prev_indent + wp->w_briopt_shift;
 
     // Add offset for number column, if 'n' is in 'cpoptions'

src/structs.h

@@ -3312,7 +3312,8 @@ struct frame_S
 				// for first
     // fr_child and fr_win are mutually exclusive
     frame_T	*fr_child;	// first contained frame
-    win_T	*fr_win;	// window that fills this frame
+    win_T	*fr_win;	// window that fills this frame; for a snapshot
+				// set to the current window
 };
 
 #define FR_LEAF	0	// frame is a leaf
@@ -3742,6 +3743,7 @@ struct window_S
     int		w_briopt_shift;	    // additional shift for breakindent
     int		w_briopt_sbr;	    // sbr in 'briopt'
     int		w_briopt_list;      // additional indent for lists
+    int		w_briopt_vcol;	    // indent for specific column
 #endif
 
     long	w_scbind_pos;

src/testdir/test_breakindent.vim

@@ -837,16 +837,17 @@ endfunc
 func Test_window_resize_with_linebreak()
   new
   53vnew
-  set linebreak
+  setl linebreak
-  set showbreak=>>
+  setl showbreak=>>
-  set breakindent
+  setl breakindent
-  set breakindentopt=shift:4
+  setl breakindentopt=shift:4
   call setline(1, "\naaaaaaaaa\n\na\naaaaa\n¯aaaaaaaaaa\naaaaaaaaaaaa\naaa\n\"a:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa - aaaaaaaa\"\naaaaaaaa\n\"a")
   redraw!
   call assert_equal(["    >>aa^@\"a: "], ScreenLines(2, 14))
   vertical resize 52
   redraw!
   call assert_equal(["    >>aaa^@\"a:"], ScreenLines(2, 14))
+  set linebreak& showbreak& breakindent& breakindentopt&
   %bw!
 endfunc
 
@@ -943,4 +944,57 @@ func Test_no_extra_indent()
   bwipeout!
 endfunc
 
+func Test_breakindent_column()
+  " restore original
+  let s:input ="\tabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP"
+  call s:test_windows('setl breakindent breakindentopt=column:10')
+  redraw!
+  " 1) default: does not indent, too wide :(
+  let expect = [
+  \ "                    ",
+  \ "    abcdefghijklmnop",
+  \ "qrstuvwxyzABCDEFGHIJ",
+  \ "KLMNOP              "
+  \ ]
+  let lines = s:screen_lines2(1, 4, 20)
+  call s:compare_lines(expect, lines)
+  " 2) lower min value, so that breakindent works
+  setl breakindentopt+=min:5
+  redraw!
+  let expect = [
+  \ "                    ",
+  \ "    abcdefghijklmnop",
+  \ "          qrstuvwxyz",
+  \ "          ABCDEFGHIJ",
+  \ "          KLMNOP    "
+  \ ]
+  let lines = s:screen_lines2(1, 5, 20)
+  " 3) set shift option -> no influence
+  setl breakindentopt+=shift:5
+  redraw!
+  let expect = [
+  \ "                    ",
+  \ "    abcdefghijklmnop",
+  \ "          qrstuvwxyz",
+  \ "          ABCDEFGHIJ",
+  \ "          KLMNOP    "
+  \ ]
+  let lines = s:screen_lines2(1, 5, 20)
+  call s:compare_lines(expect, lines)
+  " 4) add showbreak value
+  setl showbreak=++
+  redraw!
+  let expect = [
+  \ "                    ",
+  \ "    abcdefghijklmnop",
+  \ "          ++qrstuvwx",
+  \ "          ++yzABCDEF",
+  \ "          ++GHIJKLMN",
+  \ "          ++OP      "
+  \ ]
+  let lines = s:screen_lines2(1, 6, 20)
+  call s:compare_lines(expect, lines)
+  bwipeout!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4882,
 /**/
     4881,
 /**/