Small warning, automake 1.10 incompatible change in DEFAULT_INCLUDES

[Kent Boortz]

Hi,

Just something that I had to do a work around for in our build,
that others might be hit by as well.

In case you have several headers with the same name in your source
tree you might get problems from that in automake 1.10 the default
header search order will differ a bit if doing a build inside the
source tree, or from a separate directory. I.e. if you do a builds
where $(srcdir) is the same as $(builddir)

  % cd <top of source>; ./configure; make

or where they differ

  % mkdir build; cd build; <top of source>/configure; make

The problem is the automatically generated variable DEFAULT_INCLUDES,
that is filled in by automake with the path to the directory where it
will put the generated "config.h", and the paths to the "current
source directory". Earlier it was set like

  DEFAULT_INCLUDES = -I. -I$(srcdir) -I$(top_builddir)/include

ensuring that your "current source directory", independent on if one
or the other of the build methods above, would come first. Now in
automake 1.10 it is like

  DEFAULT_INCLUDES = -I. -I$(top_builddir)/include -I$(srcdir)

that in the case that you build outside the source directory, will
search for include files first in the current build directory, then
another location, and last the current source directory.

I'm sure the risk of having problems caused by this is small, why name
headers the same to begin with?!

But just wanted you to know,

kent

Ref: http://bugs.mysql.com/bug.php?id=24809

-- 
Kent Boortz, Senior Production Engineer
MySQL AB, www.mysql.com
Office: +46 18 174400 ext. 4450 (VoIP)
Office: +46 19 182931
Mobile: +46 70 2791171