* linux-low.c (linux_wait_for_event): Don't clear the `stepping'
flag.
(wait_for_sigstop): Don't leave a finished single-step SIGTRAP
pending.
(linux_continue_one_thread): Only preserve the stepping flag if
there's a pending breakpoint.
gdb/testsuite/
* gdb.threads/pending-step.c, gdb.threads/pending-step.exp: New.
