From c254399aae1fb663ff9d3038aa4725213afc2cc3 Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Mon, 24 Apr 2023 19:48:47 +0200 Subject: ftell, ftello: Fix recognition of pipes on native Windows. * m4/lseek.m4 (gl_FUNC_LSEEK): Update comment. * m4/ftello.m4 (gl_FUNC_FTELLO): On native Windows, set REPLACE_FTELLO=1 always. * doc/posix-functions/ftello.texi: Mention the behaviour on pipes. * doc/posix-functions/ftell.texi: Likewise. * doc/posix-functions/fgetpos.texi: Likewise. --- m4/ftello.m4 | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'm4/ftello.m4') diff --git a/m4/ftello.m4 b/m4/ftello.m4 index 4901b16835..e13fcd93d2 100644 --- a/m4/ftello.m4 +++ b/m4/ftello.m4 @@ -1,4 +1,4 @@ -# ftello.m4 serial 14 +# ftello.m4 serial 15 dnl Copyright (C) 2007-2023 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -37,13 +37,24 @@ AC_DEFUN([gl_FUNC_FTELLO], if test $gl_cv_var_stdin_large_offset = no; then REPLACE_FTELLO=1 fi + AC_REQUIRE([AC_CANONICAL_HOST]) + if test $REPLACE_FTELLO = 0; then + dnl On native Windows, in some circumstances, ftell(), ftello(), + dnl fgetpos(), lseek(), _lseeki64() all succeed on devices of type + dnl FILE_TYPE_PIPE. However, to match POSIX behaviour, we want + dnl ftell(), ftello(), fgetpos(), lseek() to fail when the argument fd + dnl designates a pipe. See also + dnl https://github.com/python/cpython/issues/78961#issuecomment-1093800325 + case "$host_os" in + mingw*) REPLACE_FTELLO=1 ;; + esac + fi if test $REPLACE_FTELLO = 0; then dnl Detect bug on Solaris. dnl ftell and ftello produce incorrect results after putc that followed a dnl getc call that reached EOF on Solaris. This is because the _IOREAD dnl flag does not get cleared in this case, even though _IOWRT gets set, dnl and ftell and ftello look whether the _IOREAD flag is set. - AC_REQUIRE([AC_CANONICAL_HOST]) AC_CACHE_CHECK([whether ftello works], [gl_cv_func_ftello_works], [ -- cgit v1.2.1