Passing nullptr as the second argument of memcpy/memmove
constitutes undefined behavior, even if the length argument
is zero at the same time.
Fix by protecting mem{cpy,move,chr} from nullptrs.
Found by UBSan:
qtbase/src/corelib/io/qiodevice_p.h:105:33: runtime error: null pointer passed as argument 2, which is declared to never be null
qtbase/src/corelib/io/qiodevice_p.h:175:53: runtime error: null pointer passed as argument 2, which is declared to never be null
Change-Id: I979158b0a74169ca4eb459928398ebc40f77dfb5
Reviewed-by: Alex Trotsenko <alex1973tr@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
61169b72c2