* fork.cc (fork): Use above defines instead of numerical constants.
* shared.cc (sec_user): Ditto.
* shared.h (class pinfo): Ditto.
* syscall.cc (seteuid): Ditto.
* spawn.cc (_spawnve): Ditto. Eliminate conditional.
(spawn_guts): Set child->uid = USHRT_MAX when user context will be
changed in child process.
* uinfo.cc (uinfo_init): Check for myself->uid instead of myself->psid
to avoid reloading of /etc/passwd on process startup if ntsec is off.
Use above defines instead of numerical constants.
* security.cc: Move define for MAX_SID_LEN to winsup.h.
* spawn.cc (_spawnve): Ditto.
* passwd.cc: Remove static from `passwd_in_memory_p'.
(read_etc_passwd): Remove static.
* uinfo.cc: Move global declaration of `read_etc_group' and
`group_in_memory_p' into `uinfo_init'.
(internal_getlogin): Try to get SID from current process first.
(uinfo_init): Don't set uid and gid if `myself' has a valid SID.
Only load /etc/passwd and /etc/group in that case.
`cygwin_set_impersonation_token'.
* dcrt0.cc (dll_crt0_1): Eliminate superfluous conditional
statements.
Add load statements for `ImpersonateLoggedOnUser', `LogonUserA'
and `RevertToSelf'.
* fork.cc (fork): Care for correct impersonation of parent
and child process.
* security.cc (cygwin_set_impersonation_token): New function.
(cygwin_logon_user): Ditto.
shared.h (class pinfo): New members `orig_uid', `orig_gid',
`real_uid' nad `real_gid'.
spawn.cc (spawn_guts): Care for impersonation when starting
child process in a different user context.
* syscalls.cc (setgid): Call `setegid' now. Set real_gid.
(setuid): Call `seteuid' now. Set real_uid.
(seteuid): Functionality moved from setuid to here. Care for
correct impersonation.
(setegid): Functionality moved from setgid to here.
* uinfo.cc (uinfo_init): Initialization of additional pinfo
members.
(getuid): Return real uid.
(getgid): Return real gid.
(geteuid): Return effective uid.
(getegid): Return effective gid.
include/sys/cygwin.h: Add prototypes for `cygwin_logon_user' and
`cygwin_set_impersonation_token'.
include/cygwin/version.h: Bumb API minor version to 22.
in forked process.
(interruptible): Flag as interruptible when running in main process module.
(interrupt_setup): Save return address and address of return address.
(signal_fixup_after_fork): New function. Uses above two values to restore
proper behavior to forked process.
(interrupt_on_return): Pass return address address to interupt_setup.
(interrupt_now): Pass NULL for return address address to interrupt_setup.
* fork.cc (fork): Call signal_fixup_after_fork.
* shared.h: Lint cleanups.
* winsup.h: Ditto.
interruptible.
(call_handler): Avoid suspending a thread if it owns a mutex. Only set
signal_arrived if the thread was actually interrupted.
(events_init): Initialize module information needed by interruptible().
(sigdelayed): Don't call sig_dispatch_pending since it could screw up
* init.cc (dll_entry): Record module handle of main for use by interruptible().
(proc_subproc): Reorganize handling of terminated child so that the bulk of the
processing comes from the signal thread.
(wait_sig): Force processing of waiting threads if SIGCHLD is not processed.
* sync.cc (muto::release): Set tid == 0 after lock is released or signal
processor will be confused.