The ornamental design for a pattern for handbag, as shown and described.
FIG. 1 is a front perspective view of my new pattern design;
FIG. 2 is a side view of the pattern design shown in FIG. 1, the other side being a mirror image thereof; and,
FIG. 3 is a front view of the pattern design shown in FIG. 1, the back being a mirror image thereof.
The broken line showing of the overall handbag structure, handles, handle tabs, clasp pieces, outline trim, and cutouts in the material is for illustrative purposes only and forms no part of the claimed design.