Fixes parsing of comma-separated seed lists in "init.cc" and "cql_test_env.cc" to use the standard `split_comma_separated_list` utility, avoiding manual `npos` arithmetic. The previous code relied on `npos` being `uint32_t(-1)`, which would not overflow in `uint64_t` target and exit the loop as expected. With Seastar's upcoming change to make `npos` `size_t(-1)`, this would wrap around to zero and cause an infinite loop.
Switch to `split_comma_separated_list` standardized way of tokenization that is also used in other places in the code. Empty tokens are handled as before. This prevents startup hangs and test failures when Seastar is updated.
The other commit also removes the unnecessary creation of temporary `gms::inet_address()` objects when calling `std::set<gms::inet_address>::emplace()`.
Refs: https://github.com/scylladb/seastar/pull/3236
No backport: The problem will only appear in master after the Seastar will be upgraded. The old code works with the Seastar before https://github.com/scylladb/seastar/pull/3236 (although by accident because of different integer bitsizes).
Closesscylladb/scylladb#28573
* github.com:scylladb/scylladb:
init: fix infinite loop on npos wrap with updated Seastar
init: remove unnecessary object creation in emplace calls
b01adf643c