vim-patch:9.1.0397: Wrong display with 'smoothscroll' when changing quickfix list (#28674)

Problem:  Wrong display with 'smoothscroll' when changing quickfix list.
Solution: Reset w_skipcol when replacing quickfix list (zeertzjq).

closes: vim/vim#14730

https://github.com/vim/vim/commit/c7a8eb5ff2ddd919e6f39faec93d81c52874695a

4 files changed, 165 insertions, 16 deletions

diff --git a/src/nvim/move.c b/src/nvim/move.c
index 377ccd7596..078ce3d72c 100644
--- a/src/nvim/move.c
+++ b/src/nvim/move.c
@@ -286,6 +286,7 @@ void update_topline(win_T *wp)
     }
     wp->w_topline = 1;
     wp->w_botline = 2;
+    wp->w_skipcol = 0;
     wp->w_valid |= VALID_BOTLINE|VALID_BOTLINE_AP;
     wp->w_viewport_invalid = true;
     wp->w_scbind_pos = 1;
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 94e176bd94..2713dd2a45 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -4195,6 +4195,12 @@ static void qf_fill_buffer(qf_list_T *qfl, buf_T *buf, qfline_T *old_last, int q
       }
     }
 
+    FOR_ALL_TAB_WINDOWS(tp, wp) {
+      if (wp->w_buffer == curbuf) {
+        wp->w_skipcol = 0;
+      }
+    }
+
     // Remove all undo information
     u_clearallandblockfree(curbuf);
   }
diff --git a/test/functional/legacy/scroll_opt_spec.lua b/test/functional/legacy/scroll_opt_spec.lua
index 80b8e72aec..06460a9986 100644
--- a/test/functional/legacy/scroll_opt_spec.lua
+++ b/test/functional/legacy/scroll_opt_spec.lua
@@ -913,6 +913,119 @@ describe('smoothscroll', function()
     assert_alive()
   end)
 
+  -- oldtest: Test_smoothscroll_insert_bottom()
+  it('works in Insert mode at bottom of window', function()
+    screen:try_resize(40, 9)
+    exec([[
+      call setline(1, repeat([repeat('A very long line ...', 10)], 5))
+      set wrap smoothscroll scrolloff=0
+    ]])
+    feed('Go123456789<CR>')
+    screen:expect([[
+      {1:<<<}ery long line ...A very long line ...|
+      A very long line ...A very long line ...|*5
+      123456789                               |
+      ^                                        |
+      {5:-- INSERT --}                            |
+    ]])
+  end)
+
+  -- oldtest: Test_smoothscroll_in_qf_window()
+  it('works in quickfix window when changing quickfix list', function()
+    screen:try_resize(60, 20)
+    exec([[
+      set nocompatible display=lastline
+      copen 5
+      setlocal number smoothscroll
+      let g:l = [{'text': 'foo'}] + repeat([{'text': join(range(30))}], 10)
+      call setqflist(g:l, 'r')
+      normal! G
+      wincmd t
+      let g:l1 = [{'text': join(range(1000))}]
+    ]])
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*11
+      {3:[No Name]                                                   }|
+      {1:<<<}{8: }21 22 23 24 25 26 27 28 29                              |
+      {8: 10 }|| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
+      {8:    }21 22 23 24 25 26 27 28 29                              |
+      {8: 11 }|| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
+      {8:    }21 22 23 24 25 26 27 28 29                              |
+      {2:[Quickfix List]                                             }|
+                                                                  |
+    ]])
+
+    feed([[:call setqflist([], 'r')<CR>]])
+    local screen_empty = [[
+      ^                                                            |
+      {1:~                                                           }|*11
+      {3:[No Name]                                                   }|
+      {8:  1 }                                                        |
+      {1:~                                                           }|*4
+      {2:[Quickfix List]                                             }|
+      :call setqflist([], 'r')                                    |
+    ]]
+    screen:expect(screen_empty)
+
+    feed([[:call setqflist(g:l, 'r')<CR>]])
+    local screen_l_top = [[
+      ^                                                            |
+      {1:~                                                           }|*11
+      {3:[No Name]                                                   }|
+      {8:  1 }{10:|| foo                                                  }|
+      {8:  2 }|| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
+      {8:    }21 22 23 24 25 26 27 28 29                              |
+      {8:  3 }|| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
+      {8:    }21 22 23 24 25 26 27 28 29                              |
+      {2:[Quickfix List]                                             }|
+      :call setqflist(g:l, 'r')                                   |
+    ]]
+    screen:expect(screen_l_top)
+
+    feed([[:call setqflist(g:l1, 'r')<CR>]])
+    local screen_l1_top = [[
+      ^                                                            |
+      {1:~                                                           }|*11
+      {3:[No Name]                                                   }|
+      {8:  1 }{10:|| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 }|
+      {8:    }{10:21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39}|
+      {8:    }{10: 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 5}|
+      {8:    }{10:8 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 }|
+      {8:    }{10:77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95}|
+      {2:[Quickfix List]                                             }|
+      :call setqflist(g:l1, 'r')                                  |
+    ]]
+    screen:expect(screen_l1_top)
+
+    feed('<C-W>b$<C-W>t')
+    local screen_l1_bot = [[
+      ^                                                            |
+      {1:~                                                           }|*11
+      {3:[No Name]                                                   }|
+      {1:<<<}{8: }{10: 937 938 939 940 941 942 943 944 945 946 947 948 949 950}|
+      {8:    }{10: 951 952 953 954 955 956 957 958 959 960 961 962 963 964}|
+      {8:    }{10: 965 966 967 968 969 970 971 972 973 974 975 976 977 978}|
+      {8:    }{10: 979 980 981 982 983 984 985 986 987 988 989 990 991 992}|
+      {8:    }{10: 993 994 995 996 997 998 999                            }|
+      {2:[Quickfix List]                                             }|
+      :call setqflist(g:l1, 'r')                                  |
+    ]]
+    screen:expect(screen_l1_bot)
+
+    feed([[:call setqflist([], 'r')<CR>]])
+    screen:expect(screen_empty)
+
+    feed([[:call setqflist(g:l1, 'r')<CR>]])
+    screen:expect(screen_l1_top)
+
+    feed('<C-W>b$<C-W>t')
+    screen:expect(screen_l1_bot)
+
+    feed([[:call setqflist(g:l, 'r')<CR>]])
+    screen:expect(screen_l_top)
+  end)
+
   it('works with virt_lines above and below', function()
     screen:try_resize(55, 7)
     exec([=[
@@ -986,22 +1099,6 @@ describe('smoothscroll', function()
     ]])
   end)
 
-  it('works in Insert mode at bottom of window', function()
-    screen:try_resize(40, 9)
-    exec([[
-      call setline(1, repeat([repeat('A very long line ...', 10)], 5))
-      set wrap smoothscroll scrolloff=0
-    ]])
-    feed('Go123456789<CR>')
-    screen:expect([[
-      {1:<<<}ery long line ...A very long line ...|
-      A very long line ...A very long line ...|*5
-      123456789                               |
-      ^                                        |
-      {5:-- INSERT --}                            |
-    ]])
-  end)
-
   it('<<< marker shows with tabline, winbar and splits', function()
     screen:try_resize(40, 12)
     screen:set_default_attr_ids({
diff --git a/test/old/testdir/test_scroll_opt.vim b/test/old/testdir/test_scroll_opt.vim
index 50b0e13ba4..c7b986e040 100644
--- a/test/old/testdir/test_scroll_opt.vim
+++ b/test/old/testdir/test_scroll_opt.vim
@@ -964,6 +964,51 @@ func Test_smoothscroll_insert_bottom()
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_smoothscroll_in_qf_window()
+  CheckFeature quickfix
+  CheckScreendump
+
+  let lines =<< trim END
+    set nocompatible display=lastline
+    copen 5
+    setlocal number smoothscroll
+    let g:l = [{'text': 'foo'}] + repeat([{'text': join(range(30))}], 10)
+    call setqflist(g:l, 'r')
+    normal! G
+    wincmd t
+    let g:l1 = [{'text': join(range(1000))}]
+  END
+  call writefile(lines, 'XSmoothScrollInQfWindow', 'D')
+  let buf = RunVimInTerminal('-u NONE -S XSmoothScrollInQfWindow', #{rows: 20, cols: 60})
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_1', {})
+
+  call term_sendkeys(buf, ":call setqflist([], 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_2', {})
+
+  call term_sendkeys(buf, ":call setqflist(g:l, 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_3', {})
+
+  call term_sendkeys(buf, ":call setqflist(g:l1, 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_4', {})
+
+  call term_sendkeys(buf, "\<C-W>b$\<C-W>t")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_5', {})
+
+  call term_sendkeys(buf, ":call setqflist([], 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_2', {})
+
+  call term_sendkeys(buf, ":call setqflist(g:l1, 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_4', {})
+
+  call term_sendkeys(buf, "\<C-W>b$\<C-W>t")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_5', {})
+
+  call term_sendkeys(buf, ":call setqflist(g:l, 'r')\<CR>")
+  call VerifyScreenDump(buf, 'Test_smoothscroll_in_qf_window_3', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_smoothscroll_in_zero_width_window()
   set cpo+=n number smoothscroll
   set winwidth=99999 winminwidth=0