isatty: Make it return true in Cygwin consoles on native Windows. * lib/isatty.c: Include <string.h>. (GetProcAddress): New macro. (GetNamedPipeClientProcessIdFuncType): New type. (GetNamedPipeClientProcessIdFunc): New variable. (QueryFullProcessImageNameFuncType): New type. (QueryFullProcessImageNameFunc): New variable. (initialized): New variable. (initialize): New function. (IsCygwinConsoleHandle): New function. (isatty): Invoke it. * doc/posix-functions/isatty.texi: Mention the issue.

Description:
Save and restore the working directory, possibly using a child process.

Files:
lib/savewd.h
lib/savewd.c
m4/savewd.m4

Depends-on:
assure
chdir
dosname
errno
extern-inline
fchdir
fcntl-safer
fcntl-h
raise
stdbool
stdlib
sys_wait
xalloc

configure.ac:
gl_SAVEWD

Makefile.am:
lib_SOURCES += savewd.h savewd.c

Include:
"savewd.h"

License:
GPL

Maintainer:
Paul Eggert, Jim Meyering