diff --git a/CHANGELOG.md b/CHANGELOG.md index a293c721..77d7d772 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -96,6 +96,10 @@ * Search mode: composing keys not ignored. * Crash when triple-clicking a soft-wrapped line and there is a quote character in the last column. +* Crash when reverse-scrolling (terminfo capability `rin`) such that + the current viewport ends up outside the scrollback ([#2232][2232]). + +[2232]: https://codeberg.org/dnkl/foot/issues/2232 ### Security diff --git a/terminal.c b/terminal.c index 36f8513b..e70250d8 100644 --- a/terminal.c +++ b/terminal.c @@ -3165,11 +3165,17 @@ term_scroll_reverse_partial(struct terminal *term, sixel_scroll_down(term, rows); - bool view_follows = term->grid->view == term->grid->offset; + const bool view_follows = term->grid->view == term->grid->offset; term->grid->offset -= rows; term->grid->offset += term->grid->num_rows; term->grid->offset &= term->grid->num_rows - 1; + /* How many lines from the scrollback start is the current viewport? */ + const int view_sb_start_distance = grid_row_abs_to_sb( + term->grid, term->rows, term->grid->view); + const int offset_sb_start_distance = grid_row_abs_to_sb( + term->grid, term->rows, term->grid->offset); + xassert(term->grid->offset >= 0); xassert(term->grid->offset < term->grid->num_rows); @@ -3177,6 +3183,11 @@ term_scroll_reverse_partial(struct terminal *term, term_damage_scroll(term, DAMAGE_SCROLL_REVERSE, region, rows); selection_view_up(term, term->grid->offset); term->grid->view = term->grid->offset; + } else if (unlikely(view_sb_start_distance > offset_sb_start_distance)) { + /* Part of current view is being scrolled out */ + int new_view = term->grid->offset; + selection_view_up(term, new_view); + term->grid->view = new_view; } /* Bottom non-scrolling region */ @@ -3193,11 +3204,16 @@ term_scroll_reverse_partial(struct terminal *term, erase_line(term, row); } + if (unlikely(view_sb_start_distance > offset_sb_start_distance)) + term_damage_view(term); + term->grid->cur_row = grid_row(term->grid, term->grid->cursor.point.row); #if defined(_DEBUG) for (int r = 0; r < term->rows; r++) xassert(grid_row(term->grid, r) != NULL); + for (int r = 0; r < term->rows; r++) + xassert(grid_row_in_view(term->grid, r) != NULL); #endif }