include/freetype/internal/ftmemory.h, src/base/ftdbgmem.c,
src/base/ftutil.c: udpating the memory management functions and
macros to safely deal with array size buffer overflows, this
corresponds to attemps to allocate arrays that are too large. For
an example, consider the following code:
count = read_uint32_from_file();
array = malloc( sizeof(Item) * count );
for ( nn = 0; nn < count; nn++ )
array[nn] = read_item_from_file();
if 'count' is larger than FT_UINT_MAX/sizeof(Item), the multiplication
will overflow and the array allocated will be smaller than the data
read from the file. In this case, the heap will be trashed, and this
can be used as a denial-of-service, or make the engine crash later.
the FT_ARRAY_NEW and FT_ARRAY_RENEW macro now check that the new
count is no more than FT_INT_MAX/item_size, otherwise, a new error,
named 'FT_Err_Array_Too_Large' will be returned.
note that the memory debugger now works again when FT_DEBUG_MEMORY
is defined, and FT_STRICT_ALIASING has disappeared, the corresponding
code being now the default.
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