vim-patch:9.0.1785: wrong cursor position with 'showbreak' and lcs-eol (#24852)

Problem:  wrong cursor position with 'showbreak' and lcs-eol
Solution: Add size of 'showbreak' before when 'listchars' "eol" is used.
          Also fix wrong cursor position with wrapping virtual text on
          empty line and 'showbreak'.

closes: vim/vim#12891

https://github.com/vim/vim/commit/1193951bebcff50d88403ce17dec5d3be14f131d

3 files changed, 37 insertions, 11 deletions

diff --git a/test/functional/legacy/breakindent_spec.lua b/test/functional/legacy/breakindent_spec.lua
index d7779684a4..ecd2d47f47 100644
--- a/test/functional/legacy/breakindent_spec.lua
+++ b/test/functional/legacy/breakindent_spec.lua
@@ -1,6 +1,7 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 local clear = helpers.clear
+local command = helpers.command
 local exec = helpers.exec
 local feed = helpers.feed
 
@@ -17,20 +18,15 @@ describe('breakindent', function()
     })
     screen:attach()
     exec([[
+      set listchars=eol:$
       let &signcolumn = 'yes'
-      let &showbreak = '+'
+      let &showbreak = '++'
+      let &breakindent = v:true
+      let &breakindentopt = 'shift:2'
       let leftcol = win_getid()->getwininfo()->get(0, {})->get('textoff')
       eval repeat('x', &columns - leftcol - 1)->setline(1)
       eval 'second line'->setline(2)
     ]])
-    screen:expect([[
-      {1:  }^xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx |
-      {1:  }second line                                                              |
-      {0:~                                                                          }|
-      {0:~                                                                          }|
-      {0:~                                                                          }|
-                                                                                 |
-    ]])
     feed('AX')
     screen:expect([[
       {1:  }xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxX|
@@ -40,5 +36,18 @@ describe('breakindent', function()
       {0:~                                                                          }|
       {2:-- INSERT --}                                                               |
     ]])
+    -- No line wraps, so changing 'showbreak' should lead to the same screen.
+    command('setlocal showbreak=+')
+    screen:expect_unchanged()
+    -- The first line now wraps because of "eol" in 'listchars'.
+    command('setlocal list')
+    screen:expect{grid=[[
+      {1:  }xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxX|
+      {1:  }  {0:+^$}                                                                     |
+      {1:  }second line{0:$}                                                             |
+      {0:~                                                                          }|
+      {0:~                                                                          }|
+      {2:-- INSERT --}                                                               |
+    ]]}
   end)
 end)
diff --git a/test/functional/ui/decorations_spec.lua b/test/functional/ui/decorations_spec.lua
index 4e3214da71..6c1a7a6a2c 100644
--- a/test/functional/ui/decorations_spec.lua
+++ b/test/functional/ui/decorations_spec.lua
@@ -2886,6 +2886,15 @@ bbbbbbb]])
       {1:~                             }|
                                     |
     ]]}
+    feed('zbx')
+    screen:expect{grid=[[
+        1 ^12312312312312312312312312|
+            {1:+}31231231231231231231231|
+            {1:+}23123123123123123123   |
+      {1:~                             }|
+      {1:~                             }|
+                                    |
+    ]]}
   end
 
   describe('with showbreak, smoothscroll', function()
diff --git a/test/old/testdir/test_breakindent.vim b/test/old/testdir/test_breakindent.vim
index 8d64c0dc90..3ce7d1386b 100644
--- a/test/old/testdir/test_breakindent.vim
+++ b/test/old/testdir/test_breakindent.vim
@@ -937,7 +937,9 @@ func Test_cursor_position_with_showbreak()
   let lines =<< trim END
       vim9script
       &signcolumn = 'yes'
-      &showbreak = '+ '
+      &showbreak = '++'
+      &breakindent = true
+      &breakindentopt = 'shift:2'
       var leftcol: number = win_getid()->getwininfo()->get(0, {})->get('textoff')
       repeat('x', &columns - leftcol - 1)->setline(1)
       'second line'->setline(2)
@@ -946,7 +948,13 @@ func Test_cursor_position_with_showbreak()
   let buf = RunVimInTerminal('-S XscriptShowbreak', #{rows: 6})
 
   call term_sendkeys(buf, "AX")
-  call VerifyScreenDump(buf, 'Test_cursor_position_with_showbreak', {})
+  call VerifyScreenDump(buf, 'Test_cursor_position_with_showbreak_1', {})
+  " No line wraps, so changing 'showbreak' should lead to the same screen.
+  call term_sendkeys(buf, "\<C-\>\<C-O>:setlocal showbreak=+\<CR>")
+  call VerifyScreenDump(buf, 'Test_cursor_position_with_showbreak_1', {})
+  " The first line now wraps because of "eol" in 'listchars'.
+  call term_sendkeys(buf, "\<C-\>\<C-O>:setlocal list\<CR>")
+  call VerifyScreenDump(buf, 'Test_cursor_position_with_showbreak_2', {})
 
   call StopVimInTerminal(buf)
 endfunc