--- /dev/null
+diff --git a/lib/fflush.c b/lib/fflush.c
+index 983ade0ff..5f617305a 100644
+--- a/lib/fflush.c
++++ b/lib/fflush.c
+@@ -32,8 +32,8 @@
+
+ #undef fflush
+
+-
+-#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++#define _IO_IN_BACKUP 0x100
++#if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+
+ /* Clear the stream's ungetc buffer, preserving the value of ftello (fp). */
+ static void
+@@ -72,7 +72,7 @@ clear_ungetc_buffer (FILE *fp)
+
+ #endif
+
+-#if ! (defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */)
++#if ! (defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */)
+
+ # if (defined __sferror || defined __DragonFly__ || defined __ANDROID__) && defined __SNPT
+ /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
+@@ -148,7 +148,7 @@ rpl_fflush (FILE *stream)
+ if (stream == NULL || ! freading (stream))
+ return fflush (stream);
+
+-#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++#if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+
+ clear_ungetc_buffer_preserving_position (stream);
+
--- /dev/null
+diff --git a/lib/fpurge.c b/lib/fpurge.c
+index b1d417c7a..75cf34ca2 100644
+--- a/lib/fpurge.c
++++ b/lib/fpurge.c
+@@ -62,7 +62,7 @@ fpurge (FILE *fp)
+ /* Most systems provide FILE as a struct and the necessary bitmask in
+ <stdio.h>, because they need it for implementing getc() and putc() as
+ fast macros. */
+-# if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++# if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+ fp->_IO_read_end = fp->_IO_read_ptr;
+ fp->_IO_write_ptr = fp->_IO_write_base;
+ /* Avoid memory leak when there is an active ungetc buffer. */
--- /dev/null
+diff --git a/lib/freading.c b/lib/freading.c
+index 73c28acdd..b1c397016 100644
+--- a/lib/freading.c
++++ b/lib/freading.c
+@@ -31,7 +31,7 @@ freading (FILE *fp)
+ /* Most systems provide FILE as a struct and the necessary bitmask in
+ <stdio.h>, because they need it for implementing getc() and putc() as
+ fast macros. */
+-# if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++# if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+ return ((fp->_flags & _IO_NO_WRITES) != 0
+ || ((fp->_flags & (_IO_NO_READS | _IO_CURRENTLY_PUTTING)) == 0
+ && fp->_IO_read_base != NULL));
--- /dev/null
+diff --git a/lib/fseeko.c b/lib/fseeko.c
+index 0101ab55f..542241bb2 100644
+--- a/lib/fseeko.c
++++ b/lib/fseeko.c
+@@ -47,7 +47,7 @@ fseeko (FILE *fp, off_t offset, int whence)
+ #endif
+
+ /* These tests are based on fpurge.c. */
+-#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++#if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+ if (fp->_IO_read_end == fp->_IO_read_ptr
+ && fp->_IO_write_ptr == fp->_IO_write_base
+ && fp->_IO_save_base == NULL)
+@@ -123,7 +123,7 @@ fseeko (FILE *fp, off_t offset, int whence)
+ return -1;
+ }
+
+-#if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
++#if defined _IO_ftrylockfile || __GNU_LIBRARY__ /* GNU libc, BeOS, Haiku, Linux libc5 */
+ fp->_flags &= ~_IO_EOF_SEEN;
+ fp->_offset = pos;
+ #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__