Fix selection not updating properly while scrolling

Fixes #2442

Author: kovidgoyal

docs/changelog.rst

@@ -69,6 +69,8 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Fix colors in scrollback pager off if the window has redefined terminal
   colors using escape codes (:iss:`2381`)
 
+- Fix selection not updating properly while scrolling (:iss:`2442`)
+
 - Workaround for bug in less that causes colors to reset at wrapped lines
   (:iss:`2381`)
 

kitty/screen.c

@@ -2188,6 +2188,7 @@ scroll(Screen *self, PyObject *args) {
 bool
 screen_is_selection_dirty(Screen *self) {
     IterationData q;
+    if (self->scrolled_by != self->last_rendered.scrolled_by) return true;
     iteration_data(self, &self->selection, &q, 0, true);
     if (memcmp(&q, &self->last_rendered.selection, sizeof(IterationData)) != 0) return true;
     iteration_data(self, &self->url_range, &q, 0, true);

kitty/screen.h

@@ -85,7 +85,7 @@ typedef struct {
     Selection selection, url_range;
     struct {
         IterationData selection, url;
-        unsigned int cursor_x, cursor_y;
+        unsigned int cursor_x, cursor_y, scrolled_by;
     } last_rendered;
     bool use_latin1, is_dirty, scroll_changed, reload_all_gpu_data;
     Cursor *cursor;

kitty/shaders.c

@@ -344,6 +344,7 @@ cell_prepare_to_render(ssize_t vao_idx, ssize_t gvao_idx, Screen *screen, GLfloa
         send_graphics_data_to_gpu(screen->grman->count, gvao_idx, screen->grman->render_data);
         changed = true;
     }
+    screen->last_rendered.scrolled_by = screen->scrolled_by;
     return changed;
 }