fix(terminal): keep last cursor if it's on the last row

src/nvim/mark.c

@@ -1246,7 +1246,8 @@ void mark_adjust_buf(buf_T *buf, linenr_T line1, linenr_T line2, linenr_T amount
     ONE_ADJUST(&(buf->b_last_change.mark.lnum));
 
     // last cursor position, if it was set
-    if (!equalpos(buf->b_last_cursor.mark, initpos)) {
+    if (!equalpos(buf->b_last_cursor.mark, initpos)
+        && (!by_term || buf->b_last_cursor.mark.lnum < buf->b_ml.ml_line_count)) {
       ONE_ADJUST(&(buf->b_last_cursor.mark.lnum));
     }
 
@@ -1364,9 +1365,11 @@ void mark_adjust_buf(buf_T *buf, linenr_T line1, linenr_T line2, linenr_T amount
   // adjust per-window "last cursor" positions
   for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
     WinInfo *wip = kv_A(buf->b_wininfo, i);
+    if (!by_term || wip->wi_mark.mark.lnum < buf->b_ml.ml_line_count) {
       ONE_ADJUST_CURSOR(&(wip->wi_mark.mark));
     }
   }
+}
 
 // This code is used often, needs to be fast.
 #define COL_ADJUST(pp) \

src/nvim/terminal.c

@@ -773,7 +773,7 @@ bool terminal_enter(void)
   set_terminal_winopts(s);
 
   s->term->pending.cursor = true;  // Update the cursor shape table
-  adjust_topline(s->term, buf, 0);  // scroll to end
+  adjust_topline_cursor(s->term, buf, 0);  // scroll to end
   showmode();
   ui_cursor_shape();
 
@@ -2108,7 +2108,7 @@ static void refresh_terminal(Terminal *term)
   refresh_screen(term, buf);
 
   int ml_added = buf->b_ml.ml_line_count - ml_before;
-  adjust_topline(term, buf, ml_added);
+  adjust_topline_cursor(term, buf, ml_added);
 
   // Copy pending events back to the main event queue
   multiqueue_move_events(main_loop.events, term->pending.events);
@@ -2324,8 +2324,10 @@ static void refresh_screen(Terminal *term, buf_T *buf)
   term->invalid_end = -1;
 }
 
-static void adjust_topline(Terminal *term, buf_T *buf, int added)
+static void adjust_topline_cursor(Terminal *term, buf_T *buf, int added)
 {
+  linenr_T ml_end = buf->b_ml.ml_line_count;
+
   FOR_ALL_TAB_WINDOWS(tp, wp) {
     if (wp->w_buffer == buf) {
       if (wp == curwin && is_focused(term)) {
@@ -2334,9 +2336,7 @@ static void adjust_topline(Terminal *term, buf_T *buf, int added)
         continue;
       }
 
-      linenr_T ml_end = buf->b_ml.ml_line_count;
       bool following = ml_end == wp->w_cursor.lnum + added;  // cursor at end?
-
       if (following) {
         // "Follow" the terminal output
         wp->w_cursor.lnum = ml_end;
@@ -2348,6 +2348,17 @@ static void adjust_topline(Terminal *term, buf_T *buf, int added)
       mb_check_adjust_col(wp);
     }
   }
+
+  if (ml_end == buf->b_last_cursor.mark.lnum + added) {
+    buf->b_last_cursor.mark.lnum = ml_end;
+  }
+
+  for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
+    WinInfo *wip = kv_A(buf->b_wininfo, i);
+    if (ml_end == wip->wi_mark.mark.lnum + added) {
+      wip->wi_mark.mark.lnum = ml_end;
+    }
+  }
 }
 
 static int row_to_linenr(Terminal *term, int row)

test/functional/terminal/scrollback_spec.lua

@@ -3,7 +3,7 @@ local n = require('test.functional.testnvim')()
 local Screen = require('test.functional.ui.screen')
 local tt = require('test.functional.testterm')
 
-local clear, eq = n.clear, t.eq
+local clear, eq, neq = n.clear, t.eq, t.neq
 local feed, testprg = n.feed, n.testprg
 local fn = n.fn
 local eval = n.eval
@@ -18,34 +18,74 @@ local assert_alive = n.assert_alive
 local skip = t.skip
 local is_os = t.is_os
 
-describe(':terminal scrollback', function()
+local function test_terminal_scrollback(hide_curbuf)
-  local screen
+  local screen --- @type test.functional.ui.screen
+  local buf --- @type integer
+  local chan --- @type integer
+  local otherbuf --- @type integer
+  local restore_terminal_mode --- @type boolean?
+
+  local function may_hide_curbuf()
+    if hide_curbuf then
+      eq(nil, restore_terminal_mode)
+      restore_terminal_mode = vim.startswith(api.nvim_get_mode().mode, 't')
+      api.nvim_set_current_buf(otherbuf)
+    end
+  end
+
+  local function may_restore_curbuf()
+    if hide_curbuf then
+      neq(nil, restore_terminal_mode)
+      eq(buf, fn.bufnr('#'))
+      feed('<C-^>') -- "view" in 'jumpoptions' applies to this
+      if restore_terminal_mode then
+        feed('i')
+      else
+        -- Cursor position was restored from wi_mark, not b_last_cursor.
+        -- Check that b_last_cursor and wi_mark are the same.
+        local last_cursor = fn.getpos([['"]])
+        local restored_cursor = fn.getpos('.')
+        if last_cursor[2] > 0 then
+          eq(restored_cursor, last_cursor)
+        else
+          eq({ 0, 0, 0, 0 }, last_cursor)
+          eq({ 0, 1, 1, 0 }, restored_cursor)
+        end
+      end
+      restore_terminal_mode = nil
+    end
+  end
+
+  --- @param prefix string
+  --- @param start integer
+  --- @param stop integer
+  local function feed_lines(prefix, start, stop)
+    may_hide_curbuf()
+    local data = ''
+    for i = start, stop do
+      data = data .. prefix .. tostring(i) .. '\n'
+    end
+    api.nvim_chan_send(chan, data)
+    retry(nil, 1000, function()
+      eq({ prefix .. tostring(stop), '' }, api.nvim_buf_get_lines(buf, -3, -1, true))
+    end)
+    may_restore_curbuf()
+  end
 
   before_each(function()
     clear()
+    command('set nostartofline jumpoptions+=view')
     screen = tt.setup_screen(nil, nil, 30)
-  end)
+    buf = api.nvim_get_current_buf()
-
+    chan = api.nvim_get_option_value('channel', { buf = buf })
-  local function feed_new_lines_and_wait(count)
+    if hide_curbuf then
-    local lines = {}
+      otherbuf = api.nvim_create_buf(true, false)
-    for i = 1, count do
-      table.insert(lines, 'new_line' .. tostring(i))
     end
-    table.insert(lines, '')
-    feed_data(lines)
-    retry(nil, 1000, function()
-      eq({ 'new_line' .. tostring(count), '' }, api.nvim_buf_get_lines(0, -3, -1, true))
   end)
-  end
 
   describe('when the limit is exceeded', function()
     before_each(function()
-      local lines = {}
+      feed_lines('line', 1, 30)
-      for i = 1, 30 do
-        table.insert(lines, 'line' .. tostring(i))
-      end
-      table.insert(lines, '')
-      feed_data(lines)
       screen:expect([[
         line26                        |
         line27                        |
@@ -87,7 +127,7 @@ describe(':terminal scrollback', function()
       end)
 
       it("when outputting fewer than 'scrollback' lines", function()
-        feed_new_lines_and_wait(6)
+        feed_lines('new_line', 1, 6)
         screen:expect([[
           line26                        |
           line27                        |
@@ -102,7 +142,7 @@ describe(':terminal scrollback', function()
       end)
 
       it("when outputting more than 'scrollback' lines", function()
-        feed_new_lines_and_wait(11)
+        feed_lines('new_line', 1, 11)
         screen:expect([[
           line27                        |
           {101:line2^8}                        |
@@ -117,7 +157,7 @@ describe(':terminal scrollback', function()
       end)
 
       it('when outputting more lines than whole buffer', function()
-        feed_new_lines_and_wait(20)
+        feed_lines('new_line', 1, 20)
         screen:expect([[
           ^new_line6                     |
           new_line7                     |
@@ -150,14 +190,14 @@ describe(':terminal scrollback', function()
       end)
 
       it("when outputting fewer than 'scrollback' lines", function()
-        feed_new_lines_and_wait(6)
+        feed_lines('new_line', 1, 6)
-        screen:expect_unchanged()
+        screen:expect_unchanged(hide_curbuf)
         eq({ 0, 4, 4, 0 }, fn.getpos("'m"))
         eq({ 0, 4, 6, 0 }, fn.getpos('.'))
       end)
 
       it("when outputting more than 'scrollback' lines", function()
-        feed_new_lines_and_wait(11)
+        feed_lines('new_line', 1, 11)
         screen:expect([[
           ^line27                        |
           line28                        |
@@ -175,7 +215,7 @@ describe(':terminal scrollback', function()
 
   describe('with cursor at last row', function()
     before_each(function()
-      feed_data({ 'line1', 'line2', 'line3', 'line4', '' })
+      feed_lines('line', 1, 4)
       screen:expect([[
         tty ready                     |
         line1                         |
@@ -201,7 +241,7 @@ describe(':terminal scrollback', function()
 
     it("when outputting more than 'scrollback' lines in Normal mode", function()
       feed([[<C-\><C-N>]])
-      feed_new_lines_and_wait(11)
+      feed_lines('new_line', 1, 11)
       screen:expect([[
         new_line7                     |
         new_line8                     |
@@ -222,11 +262,33 @@ describe(':terminal scrollback', function()
                                       |
       ]])
       eq({ 0, 2, 4, 0 }, fn.getpos("'m"))
+      feed('G')
+      feed_lines('new_line', 12, 31)
+      screen:expect([[
+        new_line27                    |
+        new_line28                    |
+        new_line29                    |
+        new_line30                    |
+        new_line31                    |
+        ^                              |
+                                      |
+      ]])
+      feed('gg')
+      screen:expect([[
+        ^new_line17                    |
+        new_line18                    |
+        new_line19                    |
+        new_line20                    |
+        new_line21                    |
+        new_line22                    |
+                                      |
+      ]])
+      eq({ 0, 0, 0, 0 }, fn.getpos("'m"))
     end)
 
     describe('and 1 line is printed', function()
       before_each(function()
-        feed_data({ 'line5', '' })
+        feed_lines('line', 5, 5)
       end)
 
       it('will hide the top line', function()
@@ -245,7 +307,7 @@ describe(':terminal scrollback', function()
 
       describe('and then 3 more lines are printed', function()
         before_each(function()
-          feed_data({ 'line6', 'line7', 'line8', '' })
+          feed_lines('line', 6, 8)
         end)
 
         it('will hide the top 4 lines', function()
@@ -299,7 +361,9 @@ describe(':terminal scrollback', function()
     describe('and height decreased by 1', function()
       local function will_hide_top_line()
         feed([[<C-\><C-N>]])
+        may_hide_curbuf()
         screen:try_resize(screen._width - 2, screen._height - 1)
+        may_restore_curbuf()
         screen:expect([[
           {101:line2}                       |
           line3                       |
@@ -316,7 +380,9 @@ describe(':terminal scrollback', function()
       describe('and then decreased by 2', function()
         before_each(function()
           will_hide_top_line()
+          may_hide_curbuf()
           screen:try_resize(screen._width - 2, screen._height - 2)
+          may_restore_curbuf()
         end)
 
         it('will hide the top 3 lines', function()
@@ -357,7 +423,9 @@ describe(':terminal scrollback', function()
 
     describe('and the height is decreased by 2', function()
       before_each(function()
+        may_hide_curbuf()
         screen:try_resize(screen._width, screen._height - 2)
+        may_restore_curbuf()
       end)
 
       local function will_delete_last_two_lines()
@@ -376,7 +444,9 @@ describe(':terminal scrollback', function()
       describe('and then decreased by 1', function()
         before_each(function()
           will_delete_last_two_lines()
+          may_hide_curbuf()
           screen:try_resize(screen._width, screen._height - 1)
+          may_restore_curbuf()
         end)
 
         it('will delete the last line and hide the first', function()
@@ -408,7 +478,7 @@ describe(':terminal scrollback', function()
 
   describe('with 4 lines hidden in the scrollback', function()
     before_each(function()
-      feed_data({ 'line1', 'line2', 'line3', 'line4', '' })
+      feed_lines('line', 1, 4)
       screen:expect([[
         tty ready                     |
         line1                         |
@@ -430,7 +500,9 @@ describe(':terminal scrollback', function()
         ^                              |
         {5:-- TERMINAL --}                |
       ]])
+      may_hide_curbuf()
       screen:try_resize(screen._width, screen._height - 3)
+      may_restore_curbuf()
       screen:expect([[
         line4                         |
         rows: 3, cols: 30             |
@@ -448,7 +520,9 @@ describe(':terminal scrollback', function()
         return
       end
       local function pop_then_push()
+        may_hide_curbuf()
         screen:try_resize(screen._width, screen._height + 1)
+        may_restore_curbuf()
         screen:expect([[
           line4                         |
           rows: 3, cols: 30             |
@@ -465,7 +539,9 @@ describe(':terminal scrollback', function()
         before_each(function()
           pop_then_push()
           eq(8, api.nvim_buf_line_count(0))
+          may_hide_curbuf()
           screen:try_resize(screen._width, screen._height + 3)
+          may_restore_curbuf()
         end)
 
         local function pop3_then_push1()
@@ -500,7 +576,9 @@ describe(':terminal scrollback', function()
           before_each(function()
             pop3_then_push1()
             feed('Gi')
+            may_hide_curbuf()
             screen:try_resize(screen._width, screen._height + 4)
+            may_restore_curbuf()
           end)
 
           it('will show all lines and leave a blank one at the end', function()
@@ -527,6 +605,55 @@ describe(':terminal scrollback', function()
       end)
     end)
   end)
+
+  it('reducing &scrollback deletes extra lines immediately', function()
+    feed_lines('line', 1, 30)
+    screen:expect([[
+      line26                        |
+      line27                        |
+      line28                        |
+      line29                        |
+      line30                        |
+      ^                              |
+      {5:-- TERMINAL --}                |
+    ]])
+    local term_height = 6 -- Actual terminal screen height, not the scrollback
+    -- Initial
+    local scrollback = api.nvim_get_option_value('scrollback', { buf = buf })
+    eq(scrollback + term_height, fn.line('$'))
+    eq(scrollback + term_height, fn.line('.'))
+    n.fn.setpos("'m", { 0, scrollback + 1, 4, 0 })
+    local ns = api.nvim_create_namespace('test')
+    api.nvim_buf_set_extmark(0, ns, scrollback, 0, { end_col = 6, hl_group = 'ErrorMsg' })
+    screen:expect([[
+      {101:line26}                        |
+      line27                        |
+      line28                        |
+      line29                        |
+      line30                        |
+      ^                              |
+      {5:-- TERMINAL --}                |
+    ]])
+    -- Reduction
+    scrollback = scrollback - 2
+    may_hide_curbuf()
+    api.nvim_set_option_value('scrollback', scrollback, { buf = buf })
+    may_restore_curbuf()
+    eq(scrollback + term_height, fn.line('$'))
+    eq(scrollback + term_height, fn.line('.'))
+    screen:expect_unchanged(hide_curbuf)
+    eq({ 0, scrollback + 1, 4, 0 }, n.fn.getpos("'m"))
+  end)
+end
+
+describe(':terminal scrollback', function()
+  describe('in current buffer', function()
+    test_terminal_scrollback(false)
+  end)
+
+  describe('in hidden buffer', function()
+    test_terminal_scrollback(true)
+  end)
 end)
 
 describe(':terminal prints more lines than the screen height and exits', function()
@@ -652,48 +779,6 @@ describe("'scrollback' option", function()
     eq((is_os('win') and '27: line' or '26: line'), eval("getline(line('w0') - 10)->trim(' ', 2)"))
   end)
 
-  it('deletes extra lines immediately', function()
-    -- Scrollback is 10 on setup_screen
-    local screen = tt.setup_screen(nil, nil, 30)
-    local lines = {}
-    for i = 1, 30 do
-      table.insert(lines, 'line' .. tostring(i))
-    end
-    table.insert(lines, '')
-    feed_data(lines)
-    screen:expect([[
-      line26                        |
-      line27                        |
-      line28                        |
-      line29                        |
-      line30                        |
-      ^                              |
-      {5:-- TERMINAL --}                |
-    ]])
-    local ns = api.nvim_create_namespace('test')
-    local term_height = 6 -- Actual terminal screen height, not the scrollback
-    -- Initial
-    local scrollback = api.nvim_get_option_value('scrollback', {})
-    eq(scrollback + term_height, fn.line('$'))
-    n.fn.setpos("'m", { 0, scrollback + 1, 4, 0 })
-    api.nvim_buf_set_extmark(0, ns, scrollback, 0, { end_col = 6, hl_group = 'ErrorMsg' })
-    screen:expect([[
-      {101:line26}                        |
-      line27                        |
-      line28                        |
-      line29                        |
-      line30                        |
-      ^                              |
-      {5:-- TERMINAL --}                |
-    ]])
-    -- Reduction
-    scrollback = scrollback - 2
-    api.nvim_set_option_value('scrollback', scrollback, {})
-    eq(scrollback + term_height, fn.line('$'))
-    screen:expect_unchanged()
-    eq({ 0, scrollback + 1, 4, 0 }, n.fn.getpos("'m"))
-  end)
-
   it('defaults to 10000 in :terminal buffers', function()
     set_fake_shell()
     command('terminal')