patch 8.0.1039: cannot change a line in not current buffer

Problem:    Cannot change a line in a buffer other than the current one.
Solution:   Add setbufline(). (Yasuhiro Matsumoto, Ozaki Kiichi, closes #1953)

runtime/doc/eval.txt

@@ -2316,6 +2316,9 @@ searchpos({pattern} [, {flags} [, {stopline} [, {timeout}]]])
 server2client({clientid}, {string})
 				Number	send reply string
 serverlist()			String	get a list of available servers
+setbufline( {expr}, {lnum}, {line})
+				Number	set line {lnum} to {line} in buffer
+					{expr}
 setbufvar({expr}, {varname}, {val})
 				none	set {varname} in buffer {expr} to {val}
 setcharsearch({dict})		Dict	set character search from {dict}
@@ -6858,6 +6861,19 @@ serverlist()					*serverlist()*
 		Example: >
 			:echo serverlist()
 <
+setbufline({expr}, {lnum}, {text})			*setbufline()*
+		Set line {lnum} to {text} in buffer {expr}.  To insert
+		lines use |append()|.
+
+		For the use of {expr}, see |bufname()| above.
+
+		{lnum} is used like with |setline()|.
+		This works like |setline()| for the specified buffer.
+		On success 0 is returned, on failure 1 is returned.
+
+		If {expr} is not a valid buffer or {lnum} is not valid, an
+		error message is given.
+
 setbufvar({expr}, {varname}, {val})			*setbufvar()*
 		Set option or local variable {varname} in buffer {expr} to
 		{val}.
@@ -6926,13 +6942,19 @@ setfperm({fname}, {mode})				*setfperm()* *chmod*
 
 setline({lnum}, {text})					*setline()*
 		Set line {lnum} of the current buffer to {text}.  To insert
-		lines use |append()|.
+		lines use |append()|. To set lines in another buffer use
+		|setbufline()|.
+
 		{lnum} is used like with |getline()|.
 		When {lnum} is just below the last line the {text} will be
 		added as a new line.
+
 		If this succeeds, 0 is returned.  If this fails (most likely
-		because {lnum} is invalid) 1 is returned.  Example: >
+		because {lnum} is invalid) 1 is returned.
+
+		Example: >
 			:call setline(5, strftime("%c"))
+
 <		When {text} is a |List| then line {lnum} and following lines
 		will be set to the items in the list.  Example: >
 			:call setline(5, ['aaa', 'bbb', 'ccc'])

src/Makefile

@@ -2122,6 +2122,7 @@ test_arglist \
 	test_autocmd \
 	test_backspace_opt \
 	test_breakindent \
+	test_bufline \
 	test_bufwintabinfo \
 	test_cd \
 	test_cdo \

src/evalfunc.c

@@ -328,6 +328,7 @@ static void f_searchpairpos(typval_T *argvars, typval_T *rettv);
 static void f_searchpos(typval_T *argvars, typval_T *rettv);
 static void f_server2client(typval_T *argvars, typval_T *rettv);
 static void f_serverlist(typval_T *argvars, typval_T *rettv);
+static void f_setbufline(typval_T *argvars, typval_T *rettv);
 static void f_setbufvar(typval_T *argvars, typval_T *rettv);
 static void f_setcharsearch(typval_T *argvars, typval_T *rettv);
 static void f_setcmdpos(typval_T *argvars, typval_T *rettv);
@@ -764,6 +765,7 @@ static struct fst
     {"searchpos",	1, 4, f_searchpos},
     {"server2client",	2, 2, f_server2client},
     {"serverlist",	0, 0, f_serverlist},
+    {"setbufline",	3, 3, f_setbufline},
     {"setbufvar",	3, 3, f_setbufvar},
     {"setcharsearch",	1, 1, f_setcharsearch},
     {"setcmdpos",	1, 1, f_setcmdpos},
@@ -9867,6 +9869,115 @@ f_serverlist(typval_T *argvars UNUSED, typval_T *rettv)
     rettv->vval.v_string = r;
 }
 
+/*
+ * Set line or list of lines in buffer "buf".
+ */
+    static void
+set_buffer_lines(buf_T *buf, linenr_T lnum, typval_T *lines, typval_T *rettv)
+{
+    char_u	*line = NULL;
+    list_T	*l = NULL;
+    listitem_T	*li = NULL;
+    long	added = 0;
+    linenr_T	lcount;
+    buf_T	*curbuf_save;
+    int		is_curbuf = buf == curbuf;
+
+    if (buf == NULL || buf->b_ml.ml_mfp == NULL || lnum < 1)
+    {
+	rettv->vval.v_number = 1;	/* FAIL */
+	return;
+    }
+
+    curbuf_save = curbuf;
+    curbuf = buf;
+
+    lcount = curbuf->b_ml.ml_line_count;
+
+    if (lines->v_type == VAR_LIST)
+    {
+	l = lines->vval.v_list;
+	li = l->lv_first;
+    }
+    else
+	line = get_tv_string_chk(lines);
+
+    /* default result is zero == OK */
+    for (;;)
+    {
+	if (l != NULL)
+	{
+	    /* list argument, get next string */
+	    if (li == NULL)
+		break;
+	    line = get_tv_string_chk(&li->li_tv);
+	    li = li->li_next;
+	}
+
+	rettv->vval.v_number = 1;	/* FAIL */
+	if (line == NULL || lnum < 1 || lnum > curbuf->b_ml.ml_line_count + 1)
+	    break;
+
+	/* When coming here from Insert mode, sync undo, so that this can be
+	 * undone separately from what was previously inserted. */
+	if (u_sync_once == 2)
+	{
+	    u_sync_once = 1; /* notify that u_sync() was called */
+	    u_sync(TRUE);
+	}
+
+	if (lnum <= curbuf->b_ml.ml_line_count)
+	{
+	    /* existing line, replace it */
+	    if (u_savesub(lnum) == OK && ml_replace(lnum, line, TRUE) == OK)
+	    {
+		changed_bytes(lnum, 0);
+		if (is_curbuf && lnum == curwin->w_cursor.lnum)
+		    check_cursor_col();
+		rettv->vval.v_number = 0;	/* OK */
+	    }
+	}
+	else if (added > 0 || u_save(lnum - 1, lnum) == OK)
+	{
+	    /* lnum is one past the last line, append the line */
+	    ++added;
+	    if (ml_append(lnum - 1, line, (colnr_T)0, FALSE) == OK)
+		rettv->vval.v_number = 0;	/* OK */
+	}
+
+	if (l == NULL)			/* only one string argument */
+	    break;
+	++lnum;
+    }
+
+    if (added > 0)
+	appended_lines_mark(lcount, added);
+
+    curbuf = curbuf_save;
+}
+
+/*
+ * "setbufline()" function
+ */
+    static void
+f_setbufline(argvars, rettv)
+    typval_T	*argvars;
+    typval_T	*rettv;
+{
+    linenr_T	lnum;
+    buf_T	*buf;
+
+    buf = get_buf_tv(&argvars[0], FALSE);
+    if (buf == NULL)
+	rettv->vval.v_number = 1; /* FAIL */
+    else
+    {
+	lnum = get_tv_lnum_buf(&argvars[1], buf);
+
+	set_buffer_lines(buf, lnum, &argvars[2], rettv);
+    }
+}
+
 /*
  * "setbufvar()" function
  */
@@ -10021,72 +10132,9 @@ f_setfperm(typval_T *argvars, typval_T *rettv)
     static void
 f_setline(typval_T *argvars, typval_T *rettv)
 {
-    linenr_T	lnum;
-    char_u	*line = NULL;
-    list_T	*l = NULL;
-    listitem_T	*li = NULL;
-    long	added = 0;
-    linenr_T	lcount = curbuf->b_ml.ml_line_count;
+    linenr_T	lnum = get_tv_lnum(&argvars[0]);
 
-    lnum = get_tv_lnum(&argvars[0]);
-    if (argvars[1].v_type == VAR_LIST)
-    {
-	l = argvars[1].vval.v_list;
-	li = l->lv_first;
-    }
-    else
-	line = get_tv_string_chk(&argvars[1]);
-
-    /* default result is zero == OK */
-    for (;;)
-    {
-	if (l != NULL)
-	{
-	    /* list argument, get next string */
-	    if (li == NULL)
-		break;
-	    line = get_tv_string_chk(&li->li_tv);
-	    li = li->li_next;
-	}
-
-	rettv->vval.v_number = 1;	/* FAIL */
-	if (line == NULL || lnum < 1 || lnum > curbuf->b_ml.ml_line_count + 1)
-	    break;
-
-	/* When coming here from Insert mode, sync undo, so that this can be
-	 * undone separately from what was previously inserted. */
-	if (u_sync_once == 2)
-	{
-	    u_sync_once = 1; /* notify that u_sync() was called */
-	    u_sync(TRUE);
-	}
-
-	if (lnum <= curbuf->b_ml.ml_line_count)
-	{
-	    /* existing line, replace it */
-	    if (u_savesub(lnum) == OK && ml_replace(lnum, line, TRUE) == OK)
-	    {
-		changed_bytes(lnum, 0);
-		if (lnum == curwin->w_cursor.lnum)
-		    check_cursor_col();
-		rettv->vval.v_number = 0;	/* OK */
-	    }
-	}
-	else if (added > 0 || u_save(lnum - 1, lnum) == OK)
-	{
-	    /* lnum is one past the last line, append the line */
-	    ++added;
-	    if (ml_append(lnum - 1, line, (colnr_T)0, FALSE) == OK)
-		rettv->vval.v_number = 0;	/* OK */
-	}
-
-	if (l == NULL)			/* only one string argument */
-	    break;
-	++lnum;
-    }
-
-    if (added > 0)
-	appended_lines_mark(lcount, added);
+    set_buffer_lines(curbuf, lnum, &argvars[1], rettv);
 }
 
 static void set_qf_ll_list(win_T *wp, typval_T *list_arg, typval_T *action_arg, typval_T *what_arg, typval_T *rettv);

src/testdir/test_alot.vim

@@ -3,6 +3,7 @@
 
 set belloff=all
 source test_assign.vim
+source test_bufline.vim
 source test_cd.vim
 source test_changedtick.vim
 source test_cursor_func.vim

src/testdir/test_bufline.vim

@@ -0,0 +1,26 @@
+" Tests for setbufline() and getbufline()
+
+func Test_setbufline_getbufline()
+  new
+  let b = bufnr('%')
+  hide
+  call assert_equal(0, setbufline(b, 1, ['foo', 'bar']))
+  call assert_equal(['foo'], getbufline(b, 1))
+  call assert_equal(['bar'], getbufline(b, 2))
+  call assert_equal(['foo', 'bar'], getbufline(b, 1, 2))
+  exe "bd!" b
+  call assert_equal([], getbufline(b, 1, 2))
+
+  split Xtest
+  call setline(1, ['a', 'b', 'c'])
+  let b = bufnr('%')
+  wincmd w
+  call assert_equal(1, setbufline(b, 5, ['x']))
+  call assert_equal(1, setbufline(1234, 1, ['x']))
+  call assert_equal(0, setbufline(b, 4, ['d', 'e']))
+  call assert_equal(['c'], getbufline(b, 3))
+  call assert_equal(['d'], getbufline(b, 4))
+  call assert_equal(['e'], getbufline(b, 5))
+  call assert_equal([], getbufline(b, 6))
+  exe "bwipe! " . b
+endfunc

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1039,
 /**/
     1038,
 /**/