MapArrayTypeName would copy up to NAMEDATALEN-1 bytes of the base type
name, which of course is wrong: after prepending '_' there is only room for
NAMEDATALEN-2 bytes. Aside from being the wrong result, this case would
lead to overrunning the statically allocated work buffer. This would be a
security bug if the function were ever used outside bootstrap mode, but it
isn't, at least not in any currently supported branches.
Aside from fixing the off-by-one loop logic, this patch gets rid of the
static work buffer by having MapArrayTypeName pstrdup its result; the sole
caller was already doing that, so this just requires moving the pstrdup
call. This saves a few bytes but mainly it makes the API a lot cleaner.
Back-patch on the off chance that there is some third-party code using
MapArrayTypeName with less-secure input. Pushing pstrdup into the function
should not cause any serious problems for such hypothetical code; at worst
there might be a short term memory leak.
Per Coverity scanning.
5c784d96ae