tui: clip invalid regions on resize (#8779), fixes #8774

1 files changed, 10 insertions, 1 deletions

diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index cfcfaa83a0..508d25cd3b 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -802,7 +802,16 @@ static void reset_scroll_region(UI *ui)
 static void tui_grid_resize(UI *ui, Integer g, Integer width, Integer height)
 {
   TUIData *data = ui->data;
-  ugrid_resize(&data->grid, (int)width, (int)height);
+  UGrid *grid = &data->grid;
+  ugrid_resize(grid, (int)width, (int)height);
+
+  // resize might not always be followed by a clear before flush
+  // so clip the invalid region
+  for (size_t i = 0; i < kv_size(data->invalid_regions); i++) {
+    Rect *r = &kv_A(data->invalid_regions, i);
+    r->bot = MIN(r->bot, grid->height-1);
+    r->right = MIN(r->right, grid->width-1);
+  }
 
   if (!got_winch) {  // Try to resize the terminal window.
     UNIBI_SET_NUM_VAR(data->params[0], (int)height);