--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+2012-04-22  Bruno Haible  <bruno@clisp.org>
+
+	doc: Mention reason for replacement on glibc/Linux systems.
+	* doc/posix-functions/dprintf.texi: Mention the problem with special
+	'long double' values.
+	* doc/posix-functions/fprintf.texi: Likewise.
+	* doc/posix-functions/printf.texi: Likewise.
+	* doc/posix-functions/snprintf.texi: Likewise.
+	* doc/posix-functions/sprintf.texi: Likewise.
+	* doc/posix-functions/vdprintf.texi: Likewise.
+	* doc/posix-functions/vfprintf.texi: Likewise.
+	* doc/posix-functions/vprintf.texi: Likewise.
+	* doc/posix-functions/vsnprintf.texi: Likewise.
+	* doc/posix-functions/vsprintf.texi: Likewise.
+	* doc/posix-functions/fcntl.texi: Add glibc/Linux to the list of
+	platforms with F_DUPFD_CLOEXEC problems.
+	* doc/posix-functions/glob.texi: Mention which platforms are affected
+	by the problem with symbolic links.
+	* doc/posix-functions/linkat.texi: Mention the problem with
+	AT_SYMLINK_FOLLOW on Linux.
+
 2012-04-22  Bruno Haible  <bruno@clisp.org>
 
 	pwrite: Don't replace on all platforms.

--- a/doc/posix-functions/dprintf.texi
+++ b/doc/posix-functions/dprintf.texi
@@ -17,6 +17,10 @@
 Portability problems fixed by Gnulib module @code{dprintf-posix}:
 @itemize
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6.

--- a/doc/posix-functions/fcntl.texi
+++ b/doc/posix-functions/fcntl.texi
@@ -15,6 +15,7 @@
 @item
 This function does not support @code{F_DUPFD_CLOEXEC} on some
 platforms:
+glibc with Linux kernels before 2.6.24,
 MacOS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, HP-UX 11,
 IRIX 6.5, OSF/1 5.1, Solaris 11 2010-11, Cygwin 1.7.1, Interix 3.5,
 BeOS.

--- a/doc/posix-functions/fprintf.texi
+++ b/doc/posix-functions/fprintf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/glob.texi
+++ b/doc/posix-functions/glob.texi
@@ -12,8 +12,9 @@
 This function is missing on some platforms:
 IRIX 5.3, mingw, MSVC 9, BeOS.
 @item
-This function may list symbolic links to nonexistent files among the results,
-on some platforms.
+This function does not list symbolic links to nonexistent files among the results,
+on some platforms:
+glibc 2.14, AIX 7.1, HP-UX 11, Solaris 11 2011-11.
 @item
 On platforms where @code{off_t} is a 32-bit type, this function may not
 work correctly on huge directories larger than 2 GB.

--- a/doc/posix-functions/linkat.texi
+++ b/doc/posix-functions/linkat.texi
@@ -17,6 +17,9 @@
 This function fails to reject trailing slashes on non-directories on
 some platforms:
 AIX 7.1, Solaris 11 2011-11.
+@item
+This functions does not support @code{AT_SYMLINK_FOLLOW} on some platforms:
+Linux kernel 2.6.17.
 @end itemize
 
 Portability problems not fixed by Gnulib:

--- a/doc/posix-functions/printf.texi
+++ b/doc/posix-functions/printf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/snprintf.texi
+++ b/doc/posix-functions/snprintf.texi
@@ -39,6 +39,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/sprintf.texi
+++ b/doc/posix-functions/sprintf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/vdprintf.texi
+++ b/doc/posix-functions/vdprintf.texi
@@ -24,6 +24,10 @@
 printf of @samp{long double} numbers is unsupported on some platforms:
 BeOS.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, BeOS.

--- a/doc/posix-functions/vfprintf.texi
+++ b/doc/posix-functions/vfprintf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/vprintf.texi
+++ b/doc/posix-functions/vprintf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/vsnprintf.texi
+++ b/doc/posix-functions/vsnprintf.texi
@@ -39,6 +39,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,

--- a/doc/posix-functions/vsprintf.texi
+++ b/doc/posix-functions/vsprintf.texi
@@ -20,6 +20,10 @@
 incorrect result on some platforms:
 AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
 @item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
 This function does not support the @samp{a} and @samp{A} directives on some
 platforms:
 glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,