Merge branch 'jk/no-sigpipe-during-network-transport'

On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX), the upload-pack that runs on the other end that hangs up after detecting an error could cause "git fetch" to die with a signal, which led to a flakey test. "git fetch" now ignores SIGPIPE during the network portion of its operation (this is not a problem as we check the return status from our write(2)s). * jk/no-sigpipe-during-network-transport: fetch: ignore SIGPIPE during network operation fetch: avoid calling write_or_die()