patch 8.2.5019: cannot get the first screen column of a character

Problem:    Cannot get the first screen column of a character.
Solution:   Let virtcol() optionally return a list. (closes #10482,
            closes #7964)

runtime/doc/builtin.txt

@@ -689,7 +689,8 @@ undotree()			List	undo file tree
 uniq({list} [, {func} [, {dict}]])
 				List	remove adjacent duplicates from a list
 values({dict})			List	values in {dict}
-virtcol({expr})			Number	screen column of cursor or mark
+virtcol({expr} [, {list}])	Number or List
+					screen column of cursor or mark
 visualmode([expr])		String	last visual mode used
 wildmenumode()			Number	whether 'wildmenu' mode is active
 win_execute({id}, {command} [, {silent}])
@@ -780,6 +781,7 @@ add({object}, {expr})					*add()*
 and({expr}, {expr})					*and()*
 		Bitwise AND on the two arguments.  The arguments are converted
 		to a number.  A List, Dict or Float argument causes an error.
+		Also see `or()` and `xor()`.
 		Example: >
 			:let flag = and(bits, 0x80)
 <		Can also be used as a |method|: >
@@ -936,13 +938,14 @@ autocmd_add({acmds})					*autocmd_add()*
 				item is ignored.
 		    cmd		Ex command to execute for this autocmd event
 		    event	autocmd event name. Refer to |autocmd-events|.
+		    		TODO: currently only accepts one event.
 		    group	autocmd group name. Refer to |autocmd-groups|.
 				If this group doesn't exist then it is
 				created.  If not specified or empty, then the
 				default group is used.
 		    nested	boolean flag, set to v:true to add a nested
 				autocmd.  Refer to |autocmd-nested|.
-		    once	boolean flag, set to v:true to add a autocmd
+		    once	boolean flag, set to v:true to add an autocmd
 				which executes only once. Refer to
 				|autocmd-once|.
 		    pattern	autocmd pattern string. Refer to
@@ -952,7 +955,7 @@ autocmd_add({acmds})					*autocmd_add()*
 				commands associated with the specified autocmd
 				event and group and add the {cmd}.  This is
 				useful to avoid adding the same command
-				multiple times for a autocmd event in a group.
+				multiple times for an autocmd event in a group.
 
 		Returns v:true on success and v:false on failure.
 		Examples: >
@@ -9727,7 +9730,7 @@ values({dict})						*values()*
 		Can also be used as a |method|: >
 			mydict->values()
 
-virtcol({expr})						*virtcol()*
+virtcol({expr} [, {list}])				*virtcol()*
 		The result is a Number, which is the screen column of the file
 		position given with {expr}.  That is, the last screen position
 		occupied by the character at that position, when the screen
@@ -9736,13 +9739,17 @@ virtcol({expr})						*virtcol()*
 		the <Tab>.  For example, for a <Tab> in column 1, with 'ts'
 		set to 8, it returns 8. |conceal| is ignored.
 		For the byte position use |col()|.
+
 		For the use of {expr} see |col()|.
-		When 'virtualedit' is used {expr} can be [lnum, col, off], where
-		"off" is the offset in screen columns from the start of the
-		character.  E.g., a position within a <Tab> or after the last
-		character.  When "off" is omitted zero is used.
-		When Virtual editing is active in the current mode, a position
-		beyond the end of the line can be returned. |'virtualedit'|
+
+		When 'virtualedit' is used {expr} can be [lnum, col, off],
+		where "off" is the offset in screen columns from the start of
+		the character.  E.g., a position within a <Tab> or after the
+		last character.  When "off" is omitted zero is used.  When
+		Virtual editing is active in the current mode, a position
+		beyond the end of the line can be returned.  Also see
+		|'virtualedit'|
+
 		The accepted positions are:
 		    .	    the cursor position
 		    $	    the end of the cursor line (the result is the
@@ -9754,11 +9761,22 @@ virtcol({expr})						*virtcol()*
 			    cursor is the end).  When not in Visual mode
 			    returns the cursor position.  Differs from |'<| in
 			    that it's updated right away.
+
+		If {list} is present and non-zero then virtcol() returns a List
+		with the first and last screen position occupied by the
+		character.
+
 		Note that only marks in the current file can be used.
 		Examples: >
-  virtcol(".")	   with text "foo^Lbar", with cursor on the "^L", returns 5
-  virtcol("$")	   with text "foo^Lbar", returns 9
-  virtcol("'t")    with text "	  there", with 't at 'h', returns 6
+			" With text "foo^Lbar" and cursor on the "^L":
+
+			virtcol(".")	" returns 5
+			virtcol(".", 1)	" returns [4, 5]
+			virtcol("$")	" returns 9
+
+			" With text "	  there", with 't at 'h':
+
+			virtcol("'t")	" returns 6
 <		The first column is 1.  0 is returned for an error.
 		A more advanced example that echoes the maximum length of
 		all lines: >

src/evalfunc.c

@@ -994,6 +994,7 @@ static argcheck_T arg2_string_dict[] = {arg_string, arg_dict_any};
 static argcheck_T arg2_string_list_number[] = {arg_string, arg_list_number};
 static argcheck_T arg2_string_number[] = {arg_string, arg_number};
 static argcheck_T arg2_string_or_list_dict[] = {arg_string_or_list_any, arg_dict_any};
+static argcheck_T arg2_string_or_list_bool[] = {arg_string_or_list_any, arg_bool};
 static argcheck_T arg2_string_string_or_number[] = {arg_string, arg_string_or_nr};
 static argcheck_T arg3_any_list_dict[] = {NULL, arg_list_any, arg_dict_any};
 static argcheck_T arg3_buffer_lnum_lnum[] = {arg_buffer, arg_lnum, arg_lnum};
@@ -1457,6 +1458,20 @@ ret_getreg(int argcount,
     return &t_string;
 }
 
+    static type_T *
+ret_virtcol(int argcount,
+	type2_T *argtypes UNUSED,
+	type_T	**decl_type)
+{
+    // Assume that if the second argument is passed it's non-zero
+    if (argcount == 2)
+    {
+	*decl_type = &t_list_any;
+	return &t_list_number;
+    }
+    return &t_number;
+}
+
     static type_T *
 ret_maparg(int argcount,
 	type2_T *argtypes UNUSED,
@@ -2665,8 +2680,8 @@ static funcentry_T global_functions[] =
 			ret_first_arg,	    f_uniq},
     {"values",		1, 1, FEARG_1,	    arg1_dict_any,
 			ret_list_any,	    f_values},
-    {"virtcol",		1, 1, FEARG_1,	    arg1_string_or_list_any,
-			ret_number,	    f_virtcol},
+    {"virtcol",		1, 2, FEARG_1,	    arg2_string_or_list_bool,
+			ret_virtcol,	    f_virtcol},
     {"visualmode",	0, 1, 0,	    arg1_bool,
 			ret_string,	    f_visualmode},
     {"wildmenumode",	0, 0, 0,	    NULL,
@@ -10380,23 +10395,26 @@ f_type(typval_T *argvars, typval_T *rettv)
 }
 
 /*
- * "virtcol(string)" function
+ * "virtcol(string, bool)" function
  */
     static void
 f_virtcol(typval_T *argvars, typval_T *rettv)
 {
-    colnr_T	vcol = 0;
+    colnr_T	vcol_start = 0;
+    colnr_T	vcol_end = 0;
     pos_T	*fp;
     int		fnum = curbuf->b_fnum;
     int		len;
 
     if (in_vim9script()
-	    && check_for_string_or_list_arg(argvars, 0) == FAIL)
+	    && (check_for_string_or_list_arg(argvars, 0) == FAIL
+		|| (argvars[1].v_type != VAR_UNKNOWN
+		    && check_for_bool_arg(argvars, 1) == FAIL)))
 	return;
 
     fp = var2fpos(&argvars[0], FALSE, &fnum, FALSE);
     if (fp != NULL && fp->lnum <= curbuf->b_ml.ml_line_count
-						    && fnum == curbuf->b_fnum)
+	    && fnum == curbuf->b_fnum)
     {
 	// Limit the column to a valid value, getvvcol() doesn't check.
 	if (fp->col < 0)
@@ -10407,11 +10425,23 @@ f_virtcol(typval_T *argvars, typval_T *rettv)
 	    if (fp->col > len)
 		fp->col = len;
 	}
-	getvvcol(curwin, fp, NULL, NULL, &vcol);
-	++vcol;
+	getvvcol(curwin, fp, &vcol_start, NULL, &vcol_end);
+	++vcol_start;
+	++vcol_end;
     }
 
-    rettv->vval.v_number = vcol;
+    if (argvars[1].v_type != VAR_UNKNOWN && tv_get_bool(&argvars[1]))
+    {
+	if (rettv_list_alloc(rettv) == OK)
+	{
+	    list_append_number(rettv->vval.v_list, vcol_start);
+	    list_append_number(rettv->vval.v_list, vcol_end);
+	}
+	else
+	    rettv->vval.v_number = 0;
+    }
+    else
+	rettv->vval.v_number = vcol_end;
 }
 
 /*

src/testdir/test_functions.vim

@@ -2947,4 +2947,15 @@ func Test_exepath()
   endif
 endfunc
 
+" Test for virtcol()
+func Test_virtcol()
+  enew!
+  call setline(1, "the\tquick\tbrown\tfox")
+  norm! 4|
+  call assert_equal(8, virtcol('.'))
+  call assert_equal(8, virtcol('.', v:false))
+  call assert_equal([4, 8], virtcol('.', v:true))
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/testdir/test_vim9_builtin.vim

@@ -4494,14 +4494,23 @@ def Test_values()
 enddef
 
 def Test_virtcol()
-  v9.CheckDefAndScriptFailure(['virtcol(1.1)'], ['E1013: Argument 1: type mismatch, expected string but got float', 'E1222: String or List required for argument 1'])
-  v9.CheckDefExecAndScriptFailure(['virtcol("")'], 'E1209: Invalid value for a line number')
+  v9.CheckDefAndScriptFailure(['virtcol(1.1)'], [
+    'E1013: Argument 1: type mismatch, expected string but got float',
+    'E1222: String or List required for argument 1'])
+  v9.CheckDefAndScriptFailure(['virtcol(".", "a")'], [
+    'E1013: Argument 2: type mismatch, expected bool but got string',
+    'E1212: Bool required for argument 2'])
+  v9.CheckDefExecAndScriptFailure(['virtcol("")'],
+    'E1209: Invalid value for a line number')
   new
-  setline(1, ['abcdefgh'])
+  setline(1, ['abcde和平fgh'])
   cursor(1, 4)
   assert_equal(4, virtcol('.'))
+  assert_equal([4, 4], virtcol('.', 1))
+  cursor(1, 6)
+  assert_equal([6, 7], virtcol('.', 1))
   assert_equal(4, virtcol([1, 4]))
-  assert_equal(9, virtcol([1, '$']))
+  assert_equal(13, virtcol([1, '$']))
   assert_equal(0, virtcol([10, '$']))
   bw!
 enddef

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5019,
 /**/
     5018,
 /**/