vim-patch:9.0.0205: cursor in wrong position when inserting after virtual text

Problem:    Cursor in wrong position when inserting after virtual text. (Ben
            Jackson)
Solution:   Put the cursor after the virtual text, where the text will be
            inserted. (closes vim/vim#10914)

https://github.com/vim/vim/commit/28c9f895716cfa8f1220bc41b72a534c0e10cabe

Co-authored-by: Bram Moolenaar <Bram@vim.org>

4 files changed, 50 insertions, 2 deletions

diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 24267ebd50..2917bb31ee 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1092,7 +1092,7 @@ void getvcol(win_T *wp, pos_T *pos, colnr_T *start, colnr_T *cursor, colnr_T *en
       // cursor at end
       *cursor = vcol + incr - 1;
     } else {
-      if ((State & MODE_INSERT) == 0 && !on_NUL) {
+      if (((State & MODE_INSERT) == 0 || !cts.cts_has_right_gravity) && !on_NUL) {
         // cursor is after inserted text, unless on the NUL
         vcol += cts.cts_cur_text_width;
       }
diff --git a/src/nvim/plines.c b/src/nvim/plines.c
index 2df9c23902..3b4883d5c2 100644
--- a/src/nvim/plines.c
+++ b/src/nvim/plines.c
@@ -325,6 +325,7 @@ void init_chartabsize_arg(chartabsize_T *cts, win_T *wp, linenr_T lnum, colnr_T
   cts->cts_ptr = ptr;
   cts->cts_cur_text_width = 0;
   cts->cts_has_virt_text = false;
+  cts->cts_has_right_gravity = true;
   cts->cts_row = lnum - 1;
 
   if (cts->cts_row >= 0) {
@@ -425,6 +426,7 @@ int win_lbr_chartabsize(chartabsize_T *cts, int *headp)
           Decoration decor = get_decor(mark);
           if (decor.virt_text_pos == kVTInline) {
             cts->cts_cur_text_width += decor.virt_text_width;
+            cts->cts_has_right_gravity = mt_right(mark);
             size += decor.virt_text_width;
             if (*s == TAB) {
               // tab size changes because of the inserted text
diff --git a/src/nvim/plines.h b/src/nvim/plines.h
index a15c234bba..6e4768bc7d 100644
--- a/src/nvim/plines.h
+++ b/src/nvim/plines.h
@@ -14,6 +14,7 @@ typedef struct {
   int cts_row;
 
   bool cts_has_virt_text;  // true if if a property inserts text
+  bool cts_has_right_gravity;
   int cts_cur_text_width;     // width of current inserted text
   MarkTreeIter cts_iter[1];
   // TODO(bfredl): iterator in to the marktree for scanning virt text
diff --git a/test/functional/ui/decorations_spec.lua b/test/functional/ui/decorations_spec.lua
index fa492dfcac..de3f7e7a5b 100644
--- a/test/functional/ui/decorations_spec.lua
+++ b/test/functional/ui/decorations_spec.lua
@@ -1652,11 +1652,12 @@ bbbbbbb]])
       ]]}
   end)
 
+    feed('8l')
   it('visual select highlight is correct with virtual text attatched to', function()
     insert('foo foo foo foo')
     feed('0')
     meths.buf_set_extmark(0, ns, 0, 8,
-            { virt_text = { { 'virtual text', 'Special' } }, virt_text_pos = 'inline' })
+      { virt_text = { { 'virtual text', 'Special' } }, virt_text_pos = 'inline' })
     feed('8l')
     screen:expect { grid = [[
       foo foo {28:virtual text}^foo foo                       |
@@ -1696,6 +1697,50 @@ bbbbbbb]])
       {24:-- VISUAL --}                                      |
       ]]}
   end)
+
+  it('cursor position is correct when inserting around a virtual text with right gravity set to false', function()
+    insert('foo foo foo foo')
+    meths.buf_set_extmark(0, ns, 0, 8,
+      { virt_text = { { 'virtual text', 'Special' } }, virt_text_pos = 'inline', right_gravity = false })
+    feed('0')
+    feed('8l')
+    screen:expect { grid = [[
+      foo foo {28:virtual text}^foo foo                       |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+                                                        |
+      ]]}
+
+    feed('i')
+    screen:expect { grid = [[
+      foo foo {28:virtual text}^foo foo                       |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {24:-- INSERT --}                                      |
+      ]]}
+  end)
 end)
 
 describe('decorations: virtual lines', function()