Support non-blocking pipe I/O in write() on native Windows.

* lib/unistd.in.h (write): Enable replacement also if
GNULIB_UNISTD_H_NONBLOCKING is 1.
* lib/write.c: Enable replacement also if GNULIB_NONBLOCKING.
(rpl_write): When failing to write on a non-blocking pipe, change
errno from ENOSPC to EAGAIN.
* lib/stdio.in.h (fprintf, fputc, fputs, fwrite, printf, putc,
putchar, puts, vfprintf, vprintf): Enable replacement also if
GNULIB_STDIO_H_NONBLOCKING is 1.
* lib/stdio-write.c: Enable replacements also if GNULIB_NONBLOCKING.
(CLEAR_ERRNO, HANDLE_ENOSPC): New macros.
(CLEAR_LastError, HANDLE_ERROR_NO_DATA): New macros, extracted from
CALL_WITH_SIGPIPE_EMULATION.
(CALL_WITH_SIGPIPE_EMULATION): Use them.
* m4/nonblocking.m4: New file.
* m4/write.m4 (gl_FUNC_WRITE): Enable REPLACE_WRITE also if required
for non-blocking I/O support.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize
GNULIB_UNISTD_H_NONBLOCKING.
* m4/stdio_h.m4 (gl_STDIO_H): Enable REPLACE_STDIO_WRITE_FUNCS also if
required for non-blocking I/O support.
(gl_STDIO_H_DEFAULTS): Initialize GNULIB_STDIO_H_NONBLOCKING.
* modules/nonblocking (Files): Add m4/nonblocking.m4,
lib/stdio-write.c, m4/asm-underscore.m4.
(Depends-on): Add stdio, unistd.
(configure.ac): Invoke gl_NONBLOCKING_IO. Define GNULIB_NONBLOCKING.
Set GNULIB_STDIO_H_NONBLOCKING, GNULIB_UNISTD_H_NONBLOCKING.
* modules/unistd (Makefile.am): Substitute GNULIB_UNISTD_H_NONBLOCKING.
* modules/stdio (Makefile.am): Substitute GNULIB_STDIO_H_NONBLOCKING.
* doc/posix-functions/fprintf.texi: Mention 'nonblocking' module and
problem with non-blocking pipes.
* doc/posix-functions/fputc.texi: Likewise.
* doc/posix-functions/fputs.texi: Likewise.
* doc/posix-functions/fwrite.texi: Likewise.
* doc/posix-functions/printf.texi: Likewise.
* doc/posix-functions/putc.texi: Likewise.
* doc/posix-functions/putchar.texi: Likewise.
* doc/posix-functions/puts.texi: Likewise.
* doc/posix-functions/vfprintf.texi: Likewise.
* doc/posix-functions/vprintf.texi: Likewise.
* doc/posix-functions/write.texi: Likewise.

11 files changed, 117 insertions, 18 deletions

diff --git a/doc/posix-functions/fprintf.texi b/doc/posix-functions/fprintf.texi
index e922e85e08..04c4c72cae 100644
--- a/doc/posix-functions/fprintf.texi
+++ b/doc/posix-functions/fprintf.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fprintf.html}
 
-Gnulib module: fprintf-posix or stdio, sigpipe
+Gnulib module: fprintf-posix or stdio, nonblocking, sigpipe
 
 Portability problems fixed by Gnulib module @code{fprintf-posix}:
 @itemize
@@ -64,6 +64,15 @@ This function can crash in out-of-memory conditions on some platforms:
 MacOS X 10.3, FreeBSD 6.0, NetBSD 5.0.
 @end itemize
 
+Portability problems fixed by Gnulib module @code{stdio} or @code{fprintf-posix}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
 Portability problems fixed by Gnulib module @code{stdio} or @code{fprintf-posix}, together with module @code{sigpipe}:
 @itemize
 @item
diff --git a/doc/posix-functions/fputc.texi b/doc/posix-functions/fputc.texi
index 2f09a8a98f..9d6c9fd29c 100644
--- a/doc/posix-functions/fputc.texi
+++ b/doc/posix-functions/fputc.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fputc.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/fputs.texi b/doc/posix-functions/fputs.texi
index d2c46ef8bd..7fc4bf5311 100644
--- a/doc/posix-functions/fputs.texi
+++ b/doc/posix-functions/fputs.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fputs.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/fwrite.texi b/doc/posix-functions/fwrite.texi
index d9defec9c8..20f7fb8100 100644
--- a/doc/posix-functions/fwrite.texi
+++ b/doc/posix-functions/fwrite.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fwrite.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/printf.texi b/doc/posix-functions/printf.texi
index eaee96a753..df7813f6a4 100644
--- a/doc/posix-functions/printf.texi
+++ b/doc/posix-functions/printf.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/printf.html}
 
-Gnulib module: printf-posix or stdio, sigpipe
+Gnulib module: printf-posix or stdio, nonblocking, sigpipe
 
 Portability problems fixed by Gnulib module @code{printf-posix}:
 @itemize
@@ -64,6 +64,15 @@ This function can crash in out-of-memory conditions on some platforms:
 MacOS X 10.3, FreeBSD 6.0, NetBSD 5.0.
 @end itemize
 
+Portability problems fixed by Gnulib module @code{stdio} or @code{printf-posix}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
 Portability problems fixed by Gnulib module @code{stdio} or @code{printf-posix}, together with module @code{sigpipe}:
 @itemize
 @item
diff --git a/doc/posix-functions/putc.texi b/doc/posix-functions/putc.texi
index b7011a01be..d156461ace 100644
--- a/doc/posix-functions/putc.texi
+++ b/doc/posix-functions/putc.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/putc.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/putchar.texi b/doc/posix-functions/putchar.texi
index d89ab7189f..aeb6b4307c 100644
--- a/doc/posix-functions/putchar.texi
+++ b/doc/posix-functions/putchar.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/putchar.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/puts.texi b/doc/posix-functions/puts.texi
index 69ee72e3de..ef350ac1b1 100644
--- a/doc/posix-functions/puts.texi
+++ b/doc/posix-functions/puts.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/puts.html}
 
-Gnulib module: stdio, sigpipe
+Gnulib module: stdio, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails, instead of
diff --git a/doc/posix-functions/vfprintf.texi b/doc/posix-functions/vfprintf.texi
index 7e502347de..b40a334167 100644
--- a/doc/posix-functions/vfprintf.texi
+++ b/doc/posix-functions/vfprintf.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/vfprintf.html}
 
-Gnulib module: vfprintf-posix or stdio, sigpipe
+Gnulib module: vfprintf-posix or stdio, nonblocking, sigpipe
 
 Portability problems fixed by Gnulib module @code{vfprintf-posix}:
 @itemize
@@ -64,6 +64,15 @@ This function can crash in out-of-memory conditions on some platforms:
 MacOS X 10.3, FreeBSD 6.0, NetBSD 5.0.
 @end itemize
 
+Portability problems fixed by Gnulib module @code{stdio} or @code{vfprintf-posix}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
 Portability problems fixed by Gnulib module @code{stdio} or @code{vfprintf-posix}, together with module @code{sigpipe}:
 @itemize
 @item
diff --git a/doc/posix-functions/vprintf.texi b/doc/posix-functions/vprintf.texi
index 526070e22d..342d182c64 100644
--- a/doc/posix-functions/vprintf.texi
+++ b/doc/posix-functions/vprintf.texi
@@ -4,7 +4,7 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/vprintf.html}
 
-Gnulib module: vprintf-posix or stdio, sigpipe
+Gnulib module: vprintf-posix or stdio, nonblocking, sigpipe
 
 Portability problems fixed by Gnulib module @code{vprintf-posix}:
 @itemize
@@ -64,6 +64,15 @@ This function can crash in out-of-memory conditions on some platforms:
 MacOS X 10.3, FreeBSD 6.0, NetBSD 5.0.
 @end itemize
 
+Portability problems fixed by Gnulib module @code{stdio} or @code{vprintf-posix}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
 Portability problems fixed by Gnulib module @code{stdio} or @code{vprintf-posix}, together with module @code{sigpipe}:
 @itemize
 @item
diff --git a/doc/posix-functions/write.texi b/doc/posix-functions/write.texi
index 826151c9ee..7587fbb9d9 100644
--- a/doc/posix-functions/write.texi
+++ b/doc/posix-functions/write.texi
@@ -4,9 +4,18 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/write.html}
 
-Gnulib module: write, sigpipe
+Gnulib module: write, nonblocking, sigpipe
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{nonblocking}:
+@itemize
+@item
+When writing to a non-blocking pipe whose buffer is full, this function fails
+with @code{errno} being set to @code{ENOSPC} instead of @code{EAGAIN} on some
+platforms:
+mingw.
+@end itemize
+
+Portability problems fixed by Gnulib module @code{stdio}, together with module @code{sigpipe}:
 @itemize
 @item
 When writing to a pipe with no readers, this function fails with error