Merge branch 'selection-handling-during-reflow'

Closes #924

CHANGELOG.md

@@ -55,6 +55,8 @@
   about a non-monospaced primary font.
 * Rare crash when the window is resized while a mouse selection is
   ongoing (https://codeberg.org/dnkl/foot/issues/922).
+* Large selections crossing the scrollback wrap-around
+  (https://codeberg.org/dnkl/foot/issues/924).
 
 
 ### Security

grid.c

@@ -482,6 +482,13 @@ _line_wrap(struct grid *old_grid, struct row **new_grid, struct row *row,
                 tll_remove(old_grid->sixel_images, it);
             }
         }
+
+        /*
+         * TODO: detect if the re-used row is covered by the
+         * selection. Of so, cancel the selection. The problem: we
+         * don’t know if we’ve translated the selection coordinates
+         * yet.
+         */
     }
 
     struct row_data *extra = row->extra;

selection.c

@@ -107,24 +107,34 @@ selection_view_down(struct terminal *term, int new_view)
 static void
 foreach_selected_normal(
     struct terminal *term, struct coord _start, struct coord _end,
-    bool (*cb)(struct terminal *term, struct row *row, struct cell *cell, int row_no, int col, void *data),
+    bool (*cb)(struct terminal *term, struct row *row, struct cell *cell,
+               int row_no, int col, void *data),
     void *data)
 {
     const struct coord *start = &_start;
     const struct coord *end = &_end;
 
+    const int scrollback_start = term->grid->offset + term->rows;
+    const int grid_rows = term->grid->num_rows;
+
+    /* Start/end rows, relative to the scrollback start */
+    const int rel_start_row =
+        (start->row - scrollback_start + grid_rows) & (grid_rows - 1);
+    const int rel_end_row =
+        (end->row - scrollback_start + grid_rows) & (grid_rows - 1);
+
     int start_row, end_row;
     int start_col, end_col;
 
-    if (start->row < end->row) {
+    if (rel_start_row < rel_end_row) {
         start_row = start->row;
-        end_row = end->row;
         start_col = start->col;
+        end_row = end->row;
         end_col = end->col;
-    } else if (start->row > end->row) {
+    } else if (rel_start_row > rel_end_row) {
         start_row = end->row;
-        end_row = start->row;
         start_col = end->col;
+        end_row = start->row;
         end_col = start->col;
     } else {
         start_row = end_row = start->row;
@@ -132,51 +142,77 @@ foreach_selected_normal(
         end_col = max(start->col, end->col);
     }
 
-    for (int r = start_row; r <= end_row; r++) {
+    start_row &= (grid_rows - 1);
-        size_t real_r = r & (term->grid->num_rows - 1);
+    end_row &= (grid_rows - 1);
-        struct row *row = term->grid->rows[real_r];
+
+    for (int r = start_row; r != end_row; r = (r + 1) & (grid_rows - 1)) {
+        struct row *row = term->grid->rows[r];
         xassert(row != NULL);
 
-        for (int c = start_col;
+        for (int c = start_col; c <= term->cols - 1; c++) {
-             c <= (r == end_row ? end_col : term->cols - 1);
+            if (!cb(term, row, &row->cells[c], r, c, data))
-             c++)
-        {
-            if (!cb(term, row, &row->cells[c], real_r, c, data))
                 return;
         }
 
         start_col = 0;
     }
+
+    /* Last, partial row */
+    struct row *row = term->grid->rows[end_row];
+    xassert(row != NULL);
+
+    for (int c = start_col; c <= end_col; c++) {
+        if (!cb(term, row, &row->cells[c], end_row, c, data))
+            return;
+    }
 }
 
 static void
 foreach_selected_block(
     struct terminal *term, struct coord _start, struct coord _end,
-    bool (*cb)(struct terminal *term, struct row *row, struct cell *cell, int row_no, int col, void *data),
+    bool (*cb)(struct terminal *term, struct row *row, struct cell *cell,
+               int row_no, int col, void *data),
     void *data)
 {
     const struct coord *start = &_start;
     const struct coord *end = &_end;
 
+    const int scrollback_start = term->grid->offset + term->rows;
+    const int grid_rows = term->grid->num_rows;
+
+    /* Start/end rows, relative to the scrollback start */
+    const int rel_start_row =
+        (start->row - scrollback_start + grid_rows) & (grid_rows - 1);
+    const int rel_end_row =
+        (end->row - scrollback_start + grid_rows) & (grid_rows - 1);
+
     struct coord top_left = {
-        .row = min(start->row, end->row),
+        .row = (rel_start_row < rel_end_row
+                ? start->row : end->row) & (grid_rows - 1),
         .col = min(start->col, end->col),
     };
 
     struct coord bottom_right = {
-        .row = max(start->row, end->row),
+        .row = (rel_start_row > rel_end_row
+                ? start->row : end->row) & (grid_rows - 1),
         .col = max(start->col, end->col),
     };
 
-    for (int r = top_left.row; r <= bottom_right.row; r++) {
+    int r = top_left.row;
-        size_t real_r = r & (term->grid->num_rows - 1);
+    while (true) {
-        struct row *row = term->grid->rows[real_r];
+        struct row *row = term->grid->rows[r];
         xassert(row != NULL);
 
         for (int c = top_left.col; c <= bottom_right.col; c++) {
-            if (!cb(term, row, &row->cells[c], real_r, c, data))
+            if (!cb(term, row, &row->cells[c], r, c, data))
                 return;
         }
+
+        if (r == bottom_right.row)
+            break;
+
+        r++;
+        r &= grid_rows - 1;
     }
 }
 
@@ -1108,16 +1144,8 @@ selection_finalize(struct seat *seat, struct terminal *term, uint32_t serial)
     xassert(term->selection.start.row != -1);
     xassert(term->selection.end.row != -1);
 
-    if (term->selection.start.row > term->selection.end.row ||
+    term->selection.start.row &= (term->grid->num_rows - 1);
-        (term->selection.start.row == term->selection.end.row &&
+    term->selection.end.row &= (term->grid->num_rows - 1);
-         term->selection.start.col > term->selection.end.col))
-    {
-        struct coord tmp = term->selection.start;
-        term->selection.start = term->selection.end;
-        term->selection.end = tmp;
-    }
-
-    xassert(term->selection.start.row <= term->selection.end.row);
 
     switch (term->conf->selection_target) {
     case SELECTION_TARGET_NONE: