terminal: Fix mouse coordinates issue (#12158)

Offsets of window were not taken into account when sending mouse
coordinates to the terminal. Therefore, when nu or rnu is set, the mouse
coordinates sent to the terminal were not correct. Change it to send the
correct coordinates by subtract window offset from col.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/nvim/terminal.c b/src/nvim/terminal.c
index c5e756905a..a37cc60928 100644
--- a/src/nvim/terminal.c
+++ b/src/nvim/terminal.c
@@ -992,8 +992,9 @@ static void mouse_action(Terminal *term, int button, int row, int col,
 static bool send_mouse_event(Terminal *term, int c)
 {
   int row = mouse_row, col = mouse_col, grid = mouse_grid;
+  int offset;
   win_T *mouse_win = mouse_find_win(&grid, &row, &col);
-  if (mouse_win == NULL) {
+  if (mouse_win == NULL || (offset = win_col_off(mouse_win)) > col) {
     goto end;
   }
 
@@ -1015,7 +1016,7 @@ static bool send_mouse_event(Terminal *term, int c)
       default: return false;
     }
 
-    mouse_action(term, button, row, col, drag, 0);
+    mouse_action(term, button, row, col - offset, drag, 0);
     size_t len = vterm_output_read(term->vt, term->textbuf,
                                    sizeof(term->textbuf));
     terminal_send(term, term->textbuf, (size_t)len);