Diagnose incompatible OpenLDAP versions during build and test.

With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, PostgreSQL
backends can crash at exit.  Raise a warning during "configure" based on
the compile-time OpenLDAP version number, and test the crash scenario in
the dblink test suite.  Back-patch to 9.0 (all supported versions).

1 files changed, 52 insertions, 0 deletions

diff --git a/configure b/configure
index 7a97bdc2ce0..beb65ebffaa 100755
--- a/configure
+++ b/configure
@@ -9475,6 +9475,17 @@ fi
 
 fi
 
+# PGAC_LDAP_SAFE
+# --------------
+# PostgreSQL sometimes loads libldap_r and plain libldap into the same
+# process.  Check for OpenLDAP versions known not to tolerate doing so; assume
+# non-OpenLDAP implementations are safe.  The dblink test suite exercises the
+# hazardous interaction directly.
+
+
+
+
+
 if test "$with_ldap" = yes ; then
   if test "$PORTNAME" != "win32"; then
      for ac_header in ldap.h
@@ -9491,6 +9502,47 @@ fi
 
 done
 
+     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for compatible LDAP implementation" >&5
+$as_echo_n "checking for compatible LDAP implementation... " >&6; }
+if ${pgac_cv_ldap_safe+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ldap.h>
+#if !defined(LDAP_VENDOR_VERSION) || \
+     (defined(LDAP_API_FEATURE_X_OPENLDAP) && \
+      LDAP_VENDOR_VERSION >= 20424 && LDAP_VENDOR_VERSION <= 20431)
+choke me
+#endif
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_ldap_safe=yes
+else
+  pgac_cv_ldap_safe=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_ldap_safe" >&5
+$as_echo "$pgac_cv_ldap_safe" >&6; }
+
+if test "$pgac_cv_ldap_safe" != yes; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING:
+*** With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, each backend
+*** process that loads libpq (via WAL receiver, dblink, or postgres_fdw) and
+*** also uses LDAP will crash on exit." >&5
+$as_echo "$as_me: WARNING:
+*** With OpenLDAP versions 2.4.24 through 2.4.31, inclusive, each backend
+*** process that loads libpq (via WAL receiver, dblink, or postgres_fdw) and
+*** also uses LDAP will crash on exit." >&2;}
+fi
   else
      for ac_header in winldap.h
 do :