[PATCH Libgpg-error] m4: Fix detection of gpgrt's libdir.

[Damien Goutte-Gattat]

* src/gpg-error.m4 (GPGRT_CONFIG): Handle the case where none of the
system lib directories contain a pkgconfig subdirectory.
--

When we look for gpgrt_libdir, there's a corner case if we had been able
to obtain system libdirs (using `cc -print-search-dirs`) *but* none of
those system libdirs happen to contain a valid pkgconfig subdirectory
(which may be unlikely but can and does happen when cross-compiling).

We do test for the case where we have not obtained any system libdir at
all, in which case we fallback to `${gpgrt_prefix}/lib`
(`possible_libdir1`), but we do not test if the list of libdir
candidates is reduced to nothing after we have eliminated all the
libdirs that do not contain a pkgconfig subdirectory.

This patch adds a test for this precise case.

Signed-off-by: Damien Goutte-Gattat <dgouttegattat at incenp.org>
---
 src/gpg-error.m4 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/gpg-error.m4 b/src/gpg-error.m4
index 4b5cd40..a9b96af 100644
--- a/src/gpg-error.m4
+++ b/src/gpg-error.m4
@@ -120,6 +120,10 @@ AC_DEFUN([AM_PATH_GPG_ERROR],
         fi
         if test -n "$gpgrt_libdir"; then break; fi
       done
+      if test -z "$libdir_candidates"; then
+        # No valid pkgconfig dir in any of the system directories, fallback
+        gpgrt_libdir=${possible_libdir1}
+      fi
     else
       # When we cannot determine system libdir-format, use this:
       gpgrt_libdir=${possible_libdir1}
-- 
2.35.3