If the type char is signed, then in the function
yylex_GetFloatMaskAndFloatLen(), *s can have a negative value and be converted
to a negative int32_t which is then used as an array index. It should be
converted to uint8_t instead to ensure that the value is in the bounds of the
tFloatingFirstChar, tFloatingSecondChar, and tFloatingChars arrays.
The createpatch() function was using a fixed-size buffer. I've changed it
to be dynamically allocated. I saw that the RPN format used in patches is
slightly different from the one used internally in the assembler, so I
added a new member to the Expression struct to track the patch size.
I've also limited the RPN expression length to 1MB. I realized that the
patch RPN expression could potentially be longer than the internal RPN
expression, so the internal expression would need a limit smaller than
UINT32_MAX. I thought 1MB would be a reasonable limit.
Standalone bracketed symbols like the following weren't being zero-terminated.
X EQUS {Y}
This doesn't apply to bracketed symbols that aren't standalone, but are
instead found in a string. For example, the following works even without this
fix.
X EQUS "{Y}"