terminal: dirty tracking on screen clone

src/terminal/PageList.zig

@@ -2962,6 +2962,11 @@ pub fn isDirty(self: *const PageList, pt: point.Point) bool {
     return self.getCell(pt).?.isDirty();
 }
 
+/// Mark a point as dirty, used for testing.
+fn markDirty(self: *PageList, pt: point.Point) void {
+    self.pin(pt).?.markDirty();
+}
+
 /// Represents an exact x/y coordinate within the screen. This is called
 /// a "pin" because it is a fixed point within the pagelist direct to
 /// a specific page pointer and memory offset. The benefit is that this
@@ -3020,8 +3025,12 @@ pub const Pin = struct {
         ).?.*;
     }
 
+    /// Check if this pin is dirty.
+    pub fn isDirty(self: Pin) bool {
+        return self.page.data.isRowDirty(self.y);
+    }
+
     /// Mark this pin location as dirty.
-    /// TODO: test
     pub fn markDirty(self: Pin) void {
         var set = self.page.data.dirtyBitSet();
         set.set(self.y);
@@ -4830,6 +4839,32 @@ test "PageList clone remap tracked pin not in cloned area" {
     try testing.expect(pin_remap.get(p) == null);
 }
 
+test "PageList clone full dirty" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    var s = try init(alloc, 80, 24, null);
+    defer s.deinit();
+    try testing.expectEqual(@as(usize, s.rows), s.totalRows());
+
+    // Mark a row as dirty
+    s.markDirty(.{ .active = .{ .x = 0, .y = 0 } });
+    s.markDirty(.{ .active = .{ .x = 0, .y = 12 } });
+    s.markDirty(.{ .active = .{ .x = 0, .y = 23 } });
+
+    var s2 = try s.clone(.{
+        .top = .{ .screen = .{} },
+        .memory = .{ .alloc = alloc },
+    });
+    defer s2.deinit();
+    try testing.expectEqual(@as(usize, s.rows), s2.totalRows());
+
+    // Should still be dirty
+    try testing.expect(s2.isDirty(.{ .active = .{ .x = 0, .y = 0 } }));
+    try testing.expect(s2.isDirty(.{ .active = .{ .x = 0, .y = 12 } }));
+    try testing.expect(s2.isDirty(.{ .active = .{ .x = 0, .y = 23 } }));
+}
+
 test "PageList resize (no reflow) more rows" {
     const testing = std.testing;
     const alloc = testing.allocator;

src/terminal/page.zig

@@ -500,11 +500,16 @@ pub const Page = struct {
 
         const other_rows = other.rows.ptr(other.memory)[y_start..y_end];
         const rows = self.rows.ptr(self.memory)[0 .. y_end - y_start];
-        for (rows, other_rows) |*dst_row, *src_row| try self.cloneRowFrom(
-            other,
-            dst_row,
-            src_row,
-        );
+        for (rows, other_rows) |*dst_row, *src_row| {
+            try self.cloneRowFrom(other, dst_row, src_row);
+        }
+
+        // Set our dirty range for all the rows we copied
+        var dirty_set = self.dirtyBitSet();
+        dirty_set.setRangeValue(.{
+            .start = 0,
+            .end = y_end - y_start,
+        }, true);
 
         // We should remain consistent
         self.assertIntegrity();