Only actually needed servers should be listed and none is then implied
if no servers are listed.
Outputs a warning if "none" is still set as a server.
Closes#18466
`runtests.pl` defaults to `-` if a command is not set, since
c43ad0f972.
Also:
- drop a stray `</file>`.
- replace a `nothing` with a guaranteed invalid hostname.
Ref: 4334033b43
- replace unused URLs with `-`.
Closes#18319
The idea here is to set limits per test how many allocations and maximum
amount of memory it is allowed to use. This is a means to make sure the
number and total size of allocations are kept in check and don't
mistakenly "blow up".
If runtests.pl detects that the given limits have been exceeded it fails
the test case with an error.
The `<verify>` part now supports `<limits>`, and in this section two
limits can be set for each test (verified in debug builds only):
Allocations: [number of allocation calls]
Maximum allocated: [maximum concurrent memory allocated]
Default limits (used if nothing is set in the test file):
Allocations: 1000
Maximum allocated: 1000000
Closes#17821
Due to someone being stupid, the resizing of the multi's transfer
table was actually shrinking it. Oh my.
Add test751 to reproduce, add code assertion.
Fixes#17473
Reported-by: Jeroen Ooms
Closes#17475
