doc: document sticky-EOF issue

[Paul Eggert]

I pushed this:

* doc/posix-functions/fgetc.texi (fgetc):
* doc/posix-functions/fgets.texi (fgets):
* doc/posix-functions/fread.texi (fread):
* doc/posix-functions/fscanf.texi (fscanf):
* doc/posix-functions/getc.texi (getc):
* doc/posix-functions/getchar.texi (getchar):
* doc/posix-functions/scanf.texi (scanf):
Mention that glibc and default Solaris do not conform to
C99 and POSIX-2001 or later, with respect to how getchar
etc. behave when feof reports nonzero.
diff --git a/doc/posix-functions/fgetc.texi b/doc/posix-functions/fgetc.texi
index acf7ad7..55033fa 100644
--- a/doc/posix-functions/fgetc.texi
+++ b/doc/posix-functions/fgetc.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @item
diff --git a/doc/posix-functions/fgets.texi b/doc/posix-functions/fgets.texi
index b14917e..2eb8aa2 100644
--- a/doc/posix-functions/fgets.texi
+++ b/doc/posix-functions/fgets.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @end itemize
diff --git a/doc/posix-functions/fread.texi b/doc/posix-functions/fread.texi
index 1d64249..626d61f 100644
--- a/doc/posix-functions/fread.texi
+++ b/doc/posix-functions/fread.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @item
diff --git a/doc/posix-functions/fscanf.texi b/doc/posix-functions/fscanf.texi
index fef2e51..cd3d6ec 100644
--- a/doc/posix-functions/fscanf.texi
+++ b/doc/posix-functions/fscanf.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @item
diff --git a/doc/posix-functions/getc.texi b/doc/posix-functions/getc.texi
index 514b0f7..2069cdc 100644
--- a/doc/posix-functions/getc.texi
+++ b/doc/posix-functions/getc.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @end itemize
diff --git a/doc/posix-functions/getchar.texi b/doc/posix-functions/getchar.texi
index 3acea34..37ee44b 100644
--- a/doc/posix-functions/getchar.texi
+++ b/doc/posix-functions/getchar.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @end itemize
diff --git a/doc/posix-functions/scanf.texi b/doc/posix-functions/scanf.texi
index 0c4e264..0948e5f 100644
--- a/doc/posix-functions/scanf.texi
+++ b/doc/posix-functions/scanf.texi
@@ -18,6 +18,13 @@ mingw, MSVC 9.
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+C99 and POSIX-2001 and later require end-of-file to be sticky, that
+is, they require this function to act as if it reads end-of-file if
address@hidden would return nonzero.  However, on some systems this
+function attempts to read from the underlying file descriptor even if
+the stream's end-of-file indicator is set.  These systems include
+glibc and default Solaris.
address@hidden
 On Windows platforms (excluding Cygwin), this function does not set 
@code{errno}
 upon failure.
 @item