Wrong order of operations results in the return code being 0/1.

If the plugin ever returns an error the variables weren't initialized so
when they were freed they could corrupt memory.

Bug 2790

>= 15.08 for some reports.

Prevents correct error handling by rc being 0/1 instead of the original
return code.

Also fix slurm_send_only_controller_msg and slurm_send_only_node_msg
although these only result in bad printed values in the debug message.

Bug 2120

This bug was introduced by commit 21c52d2f
which fixed a different problem tracking resources associated with suspended
jobs. There are subtle differences between jobs that are suspended by a
user/administrator and jobs suspended by gang scheduling which resulted in
undercounting allocated CPUs when a job suspended by gang scheduling
was active at the same time of a slurmctld reconfiguration request.
See bugs 2353 (original bug related to commit 21c52d2f
and bug 2765

accounts) no default account is printed, previously NULL was printed.

This is just not printing it, but whole function should probably be
revisited as the rigmarole can probably be avoided as we always know what
the default is going to be if none is specified (first off the list).

The problem with that though is if the user has been added to a cluster
already and they have a default, but then added to a new cluster where
they don't have a default.  In this case you want to keep the first
clusters default, but set the default for the second cluster.

Bug 2725

Add missing unlock before return. Coverity 44888.

Coverity 44891.

Coverity 44992.

Needs to unlock here, not re-lock the lock.

Prevent '--preserve' from being inadvertanly enabled by '-j'.

Still testing 16.05 on my NetBSD/amd64 workstation ...
Just encountered a crash with scancel(1).
njoly@lanfeust [~]> sbatch --wrap "sleep 3600"
Submitted batch job 4680
njoly@lanfeust [~]> scancel 4680
scancel: Error detected by libpthread: Invalid condition variable.
Detected by file "/local/src/NetBSD/src/lib/libpthread/pthread_cond.c", line 140, function "pthread_cond_timedwait".
See pthread(3) for information.
zsh: abort (core dumped)  scancel 4680
Checking the code show indeed that pthread_cond_wait() call from scancel.c:_signal_job_by_str() use an uninitialised condition variable "num_active_threads_cond"
The attached patch, which add the missing pthread_cond_init() seems to fix it.
bug 2753

and the slurmctld doesn't wait long enough for the response it would give
up leaving the connection open and create a situation where the next message
sent could receive the response of the first one.

Bug 2739

Bug #2713.

Correct description of the SLURMD_NODENAME environment variable
in the sbatch and srun man pages.

when in use.

The problem here is the polling threads in the various acct_gather codes
were detached and could possibly still be polling after the plugin had
been unloaded making a seg fault with a backtrace like this...

#0  0x00007fe7af008c00 in ?? ()
#1  0x00007fe7b1138479 in __nptl_deallocate_tsd () at pthread_create.c:175
#2  0x00007fe7b11398b0 in __nptl_deallocate_tsd () at pthread_create.c:326
#3  start_thread (arg=0x7fe7b1f12700) at pthread_create.c:346
#4  0x00007fe7b0e6fb5d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

The fix was to make the threads non-detached and join them before calling
a dlclose.

trying to verify the cluster name (which may try to /create/ files or
directories) *before* dropping privs results in a fatal error as
slurmctld tries to create items which ultimately fail.  Moving
this process until after the privs and uid have changed allows
the process to succeed.

Reported by Jon Nelson <jdnelson@dyn.com>

Bug 2728

make it to the slurmctld when using message aggregation.

make sure we handle it correctly when the database comes back up.