We no longer have undo history directly in globals.
Z6HI3K55DX3BK25SGJ5B5KYGNRPV6WH65QLN65BFPWD7L6WB7IHQC
LF7BWEG4DKQI7NMXMZC4LC2BE5PB42HK5PD6OYBNIDMAZBJASOKQC
YT5P6TO64XSMCZGTT4SVNFOWUN5ECNXTWCMFXN3YCDZUNH4H3IFAC
73OCE2MCBJJZZMN2KYPJTBOUCKBZAOQ2QIAMTGCNOOJ2AJAXFT2AC
OTIBCAUJ3KDQJLVDN3A536DLZGNRYMGJLORZVR3WLCGXGO6UGO6AC
AVTNUQYRBW7IX2YQ3KDLVQ23RGW3BAKTAE7P73ASBYNKOHMQMH5AC
App.initialize_globals() -- in particular, forget all undo history
App.initialize_globals()