vim-patch:9.0.1759: Visual highlight not working with cursor at end of screen line (#24806)

Problem:  Visual highlight not working with cursor at end of screen line
          and 'showbreak'.
Solution: Only update "vcol_prev" when drawing buffer text.

closes: vim/vim#12865

https://github.com/vim/vim/commit/8fc6a1dae07aa63faa6bfe6ed93888635745830c

5 files changed, 119 insertions, 80 deletions

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index e531704970..753baa2675 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -2940,9 +2940,12 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
       wlv.char_attr = hl_combine_attr(wlv.line_attr_lowprio, wlv.char_attr);
     }
 
+    if (wlv.draw_state == WL_LINE) {
+      vcol_prev = wlv.vcol;
+    }
+
     // Store character to be displayed.
     // Skip characters that are left of the screen for 'nowrap'.
-    vcol_prev = wlv.vcol;
     if (wlv.draw_state < WL_LINE || n_skip <= 0) {
       // Store the character.
       if (wp->w_p_rl && utf_char2cells(mb_c) > 1) {
diff --git a/test/functional/legacy/display_spec.lua b/test/functional/legacy/display_spec.lua
index 482b88eae8..89120baea9 100644
--- a/test/functional/legacy/display_spec.lua
+++ b/test/functional/legacy/display_spec.lua
@@ -9,6 +9,34 @@ local command = helpers.command
 describe('display', function()
   before_each(clear)
 
+  -- oldtest: Test_visual_block_scroll()
+  it('redraws properly after scrolling with matchparen loaded and scrolloff=1', function()
+    local screen = Screen.new(30, 7)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [1] = {bold = true},
+      [2] = {background = Screen.colors.LightGrey},
+    })
+
+    exec([[
+      source $VIMRUNTIME/plugin/matchparen.vim
+      set scrolloff=1
+      call setline(1, ['a', 'b', 'c', 'd', 'e', '', '{', '}', '{', 'f', 'g', '}'])
+      call cursor(5, 1)
+    ]])
+
+    feed('V<c-d><c-d>')
+    screen:expect([[
+      {2:{}                             |
+      {2:}}                             |
+      {2:{}                             |
+      {2:f}                             |
+      ^g                             |
+      }                             |
+      {1:-- VISUAL LINE --}             |
+    ]])
+  end)
+
   -- oldtest: Test_display_scroll_at_topline()
   it('scroll when modified at topline vim-patch:8.2.1488', function()
     local screen = Screen.new(20, 4)
diff --git a/test/functional/legacy/visual_mode_spec.lua b/test/functional/legacy/visual_mode_spec.lua
deleted file mode 100644
index 1a08fb4c0e..0000000000
--- a/test/functional/legacy/visual_mode_spec.lua
+++ /dev/null
@@ -1,79 +0,0 @@
-local helpers = require('test.functional.helpers')(after_each)
-
-local Screen = require('test.functional.ui.screen')
-local clear = helpers.clear
-local feed = helpers.feed
-local exec = helpers.exec
-
-before_each(clear)
-
-describe('visual line mode', function()
-  -- oldtest: Test_visual_block_scroll()
-  it('redraws properly after scrolling with matchparen loaded and scrolloff=1', function()
-    local screen = Screen.new(30, 7)
-    screen:attach()
-    screen:set_default_attr_ids({
-      [1] = {bold = true},
-      [2] = {background = Screen.colors.LightGrey},
-    })
-
-    exec([[
-      source $VIMRUNTIME/plugin/matchparen.vim
-      set scrolloff=1
-      call setline(1, ['a', 'b', 'c', 'd', 'e', '', '{', '}', '{', 'f', 'g', '}'])
-      call cursor(5, 1)
-    ]])
-
-    feed('V<c-d><c-d>')
-    screen:expect([[
-      {2:{}                             |
-      {2:}}                             |
-      {2:{}                             |
-      {2:f}                             |
-      ^g                             |
-      }                             |
-      {1:-- VISUAL LINE --}             |
-    ]])
-  end)
-end)
-
-describe('visual block mode', function()
-  -- oldtest: Test_visual_block_with_virtualedit()
-  it('shows selection correctly with virtualedit=block', function()
-    local screen = Screen.new(30, 7)
-    screen:set_default_attr_ids({
-      [1] = {bold = true},  -- ModeMsg
-      [2] = {background = Screen.colors.LightGrey},  -- Visual
-      [3] = {foreground = Screen.colors.Blue, bold = true}  -- NonText
-    })
-    screen:attach()
-
-    exec([[
-      call setline(1, ['aaaaaa', 'bbbb', 'cc'])
-      set virtualedit=block
-      normal G
-    ]])
-
-    feed('<C-V>gg$')
-    screen:expect([[
-      {2:aaaaaa}^                        |
-      {2:bbbb   }                       |
-      {2:cc     }                       |
-      {3:~                             }|
-      {3:~                             }|
-      {3:~                             }|
-      {1:-- VISUAL BLOCK --}            |
-    ]])
-
-    feed('<Esc>gg<C-V>G$')
-    screen:expect([[
-      {2:aaaaaa }                       |
-      {2:bbbb   }                       |
-      {2:cc}^ {2:    }                       |
-      {3:~                             }|
-      {3:~                             }|
-      {3:~                             }|
-      {1:-- VISUAL BLOCK --}            |
-    ]])
-  end)
-end)
diff --git a/test/functional/legacy/visual_spec.lua b/test/functional/legacy/visual_spec.lua
new file mode 100644
index 0000000000..629fab5eb5
--- /dev/null
+++ b/test/functional/legacy/visual_spec.lua
@@ -0,0 +1,69 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local Screen = require('test.functional.ui.screen')
+local clear = helpers.clear
+local feed = helpers.feed
+local exec = helpers.exec
+
+before_each(clear)
+
+describe('Visual highlight', function()
+  local screen
+
+  before_each(function()
+    screen = Screen.new(50, 6)
+    screen:set_default_attr_ids({
+      [0] = {foreground = Screen.colors.Blue, bold = true},  -- NonText
+      [1] = {bold = true},  -- ModeMsg
+      [2] = {background = Screen.colors.LightGrey},  -- Visual
+    })
+    screen:attach()
+  end)
+
+  -- oldtest: Test_visual_block_with_virtualedit()
+  it('shows selection correctly with virtualedit=block', function()
+    exec([[
+      call setline(1, ['aaaaaa', 'bbbb', 'cc'])
+      set virtualedit=block
+      normal G
+    ]])
+
+    feed('<C-V>gg$')
+    screen:expect([[
+      {2:aaaaaa}^                                            |
+      {2:bbbb   }                                           |
+      {2:cc     }                                           |
+      {0:~                                                 }|
+      {0:~                                                 }|
+      {1:-- VISUAL BLOCK --}                                |
+    ]])
+
+    feed('<Esc>gg<C-V>G$')
+    screen:expect([[
+      {2:aaaaaa }                                           |
+      {2:bbbb   }                                           |
+      {2:cc}^ {2:    }                                           |
+      {0:~                                                 }|
+      {0:~                                                 }|
+      {1:-- VISUAL BLOCK --}                                |
+    ]])
+  end)
+
+  -- oldtest: Test_visual_hl_with_showbreak()
+  it("with cursor at end of screen line and 'showbreak'", function()
+    exec([[
+      setlocal showbreak=+
+      call setline(1, repeat('a', &columns + 10))
+      normal g$v4lo
+    ]])
+
+    screen:expect([[
+      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa^a|
+      {0:+}{2:aaaa}aaaaaa                                       |
+      {0:~                                                 }|
+      {0:~                                                 }|
+      {0:~                                                 }|
+      {1:-- VISUAL --}                                      |
+    ]])
+  end)
+end)
diff --git a/test/old/testdir/test_visual.vim b/test/old/testdir/test_visual.vim
index 04282416bb..a12ecefc73 100644
--- a/test/old/testdir/test_visual.vim
+++ b/test/old/testdir/test_visual.vim
@@ -1558,5 +1558,23 @@ func Test_heap_buffer_overflow()
   set updatecount&
 endfunc
 
+" Test Visual highlight with cursor at end of screen line and 'showbreak'
+func Test_visual_hl_with_showbreak()
+  CheckScreendump
+
+  let lines =<< trim END
+    setlocal showbreak=+
+    call setline(1, repeat('a', &columns + 10))
+    normal g$v4lo
+  END
+  call writefile(lines, 'XTest_visual_sbr', 'D')
+
+  let buf = RunVimInTerminal('-S XTest_visual_sbr', {'rows': 6, 'cols': 50})
+  call VerifyScreenDump(buf, 'Test_visual_hl_with_showbreak', {})
+
+  " clean up
+  call term_sendkeys(buf, "\<Esc>")
+  call StopVimInTerminal(buf)
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab