* pointer would get broken if the savestack is moved on reallocation.
* SSNEWa() works like SSNEW(), but also aligns the data to the specified
* number of bytes. MEM_ALIGNBYTES is perhaps the most useful. The
- * alignment will be preserved therough savestack reallocation *only* if
+ * alignment will be preserved through savestack reallocation *only* if
* realloc returns data aligned to a size divisible by "align"!
*
* SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.