On Sat, Mar 20, 2021 at 10:27:28AM +0100, pierre.labastie@neuf.fr wrote:

From: Pierre Labastie <redacted>

Autoheader uses the AC_DEFINE macros (and a few others) to populate
the config.h.in file. The autotools documentation does not tell
what happens if AC_DEFINE is used twice for the same identifier.

This patch prevents using AC_DEFINE twice for
HAVE_OWN_FIEMAP_EXTENT_DEFINE, preserving the logic (using the
fact that an undefined identifier in a preprocessor directive is
taken as zero).

Signed-off-by: Pierre Labastie <redacted>

Added to devel, thanks.