Merge pull request #14020 from chentau/float_resize

Update lines after shrinking floating window

src/nvim/grid_defs.h

@@ -76,6 +76,12 @@ typedef struct {
   int comp_row;
   int comp_col;
 
+  // Requested width and height of the grid upon resize. Used by
+  // `ui_compositor` to correctly determine which regions need to
+  // be redrawn.
+  int comp_width;
+  int comp_height;
+
   // z-index of the grid. Grids with higher index is draw on top.
   // default_grid.comp_index is always zero.
   size_t comp_index;
@@ -86,6 +92,6 @@ typedef struct {
 } ScreenGrid;
 
 #define SCREEN_GRID_INIT { 0, NULL, NULL, NULL, NULL, NULL, 0, 0, false, \
-                           false, 0, 0, false, true, 0, 0, 0,  false }
+                           false, 0, 0, false, true, 0, 0, 0, 0, 0,  false }
 
 #endif  // NVIM_GRID_DEFS_H

src/nvim/screen.c

@@ -6274,6 +6274,9 @@ retry:
   tab_page_click_defs = new_tab_page_click_defs;
   tab_page_click_defs_size = Columns;
 
+  default_grid.comp_height = Rows;
+  default_grid.comp_width = Columns;
+
   default_grid.row_offset = 0;
   default_grid.col_offset = 0;
   default_grid.handle = DEFAULT_GRID_HANDLE;

src/nvim/ui_compositor.c

@@ -127,6 +127,9 @@ bool ui_comp_put_grid(ScreenGrid *grid, int row, int col, int height, int width,
                       bool valid, bool on_top)
 {
   bool moved;
+
+  grid->comp_height = height;
+  grid->comp_width = width;
   if (grid->comp_index != 0) {
     moved = (row != grid->comp_row) || (col != grid->comp_col);
     if (ui_comp_should_draw()) {
@@ -334,17 +337,25 @@ static void compose_line(Integer row, Integer startcol, Integer endcol,
   sattr_T *bg_attrs = &default_grid.attrs[default_grid.line_offset[row]
                                           +(size_t)startcol];
 
+  int grid_width, grid_height;
   while (col < endcol) {
     int until = 0;
     for (size_t i = 0; i < kv_size(layers); i++) {
       ScreenGrid *g = kv_A(layers, i);
-      if (g->comp_row > row || row >= g->comp_row + g->Rows
+      // compose_line may have been called after a shrinking operation but
+      // before the resize has actually been applied. Therefore, we need to
+      // first check to see if any grids have pending updates to width/height,
+      // to ensure that we don't accidentally put any characters into `linebuf`
+      // that have been invalidated.
+      grid_width = MIN(g->Columns, g->comp_width);
+      grid_height = MIN(g->Rows, g->comp_height);
+      if (g->comp_row > row || row >= g->comp_row + grid_height
           || g->comp_disabled) {
         continue;
       }
-      if (g->comp_col <= col && col < g->comp_col+g->Columns) {
+      if (g->comp_col <= col && col < g->comp_col + grid_width) {
         grid = g;
-        until = g->comp_col+g->Columns;
+        until = g->comp_col + grid_width;
       } else if (g->comp_col > col) {
         until = MIN(until, g->comp_col);
       }

src/nvim/window.c

@@ -710,7 +710,7 @@ int win_fdccol_count(win_T *wp)
 }
 
 
-static void ui_ext_win_position(win_T *wp)
+void ui_ext_win_position(win_T *wp)
 {
   if (!wp->w_floating) {
     ui_call_win_pos(wp->w_grid.handle, wp->handle, wp->w_winrow,