For the tests I've compiled "rsync" from the latest GIT repository sources.
This happens only when SRC is an SSH remote location. Example:
famzah@vbox:~$ rsync email@example.com:/boot/initrd.img-3.2.0-36-generic-pae /tmp/test ; echo "Exit code: $?"
rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at rsync.c(610) [sender=3.1.0dev]
Exit code: 0
Here is how the process list looks like:
famzah@vbox:~$ ps xfww -o pid,user,tty,command
PID USER TT COMMAND
5076 famzah ? sshd: famzah@notty
5077 famzah ? \_ rsync --server --sender -e.Lsf . /boot/initrd.img-3.2.0-36-generic-pae
2996 famzah pts/1 \_ /bin/bash
4960 famzah pts/1 | \_ rsync firstname.lastname@example.org:/boot/initrd.img-3.2.0-36-generic-pae /tmp/test
4961 famzah pts/1 | \_ ssh -l famzah 127.0.0.1 rsync --server --sender -e.Lsf . /boot/initrd.img-3.2.
5078 famzah pts/1 | \_ rsync email@example.com:/boot/initrd.img-3.2.0-36-generic-pae /tmp/test
I have killed the "rsync" sender process at the _remote_ location with SIGTERM (PID=5077 in the example above).
Rsync properly indicates that the problem occurred in [sender=3.1.0dev] and also displays that exit code should be 20. But in the end, the rsync process terminates with exit code 0 which is incorrect (Success).
While trying this a few times, I noticed that sometimes "rsync" terminates with a proper exit code if the error occurs in the local "receiver" or "generator" processes. I get "error in rsync protocol data stream (code 12) at io.c" then and the final exit code of "rsync" is 12, as expected.
I also tried all other combinations:
* sync between local SRC and local DST
* sync between local SRC and remote DST over SSH
* killing any of the "rsync" processes (receiver, generator, sender, or SSH tunnel)
The only problem I got with the incorrect final exit code is when I transfer with remote SRC over SSH and local DST, as demonstrated. Furthermore, the "sender" needs to be killed with SIGTERM, which seems to be propagated back to the "receiver" process by the rsync protocol. Killing the "sender" with SIGKILL causes immediate termination and therefore an rsync protocol error at the side of the "receiver", which exits properly with a non-zero exit code.
The exit code gets passed from the sender to the receiver, but the generator doesn't get notified about it, so it exits with the wrong code. I have checked in a fix for the issue into git. Thanks for the report!