known to really NEED it as another system that doesn't have it came up:
very old Linux libc5-based systems (as addition to all HPUX versions).

The only known system at this point is AIX.

defines in the public external header files

make an adjustment to catch this.

disables the host name check in the FOLLOWLOCATION code. With that option
set, libcurl will send user+password to all hosts.

AIX when this fix is applied and I cannot see how this will break any
systems.

the design draft mentioned and what I think is fit

decreased the write buffer size to 16KB to perform a lot better on Windows(!)

for storage and retrieval of private data in the curl handle.

CURLE_OPERATION_TIMEOUTED

too, as Emiliano Ida has confirmed it to work