From 8c7900c40bc5e1607277a2573c5b29fb8d5bc5be Mon Sep 17 00:00:00 2001
From: Nicolas Williams <nico@twosigma.com>
Date: Fri, 2 Oct 2020 19:49:19 -0500
Subject: [PATCH] hdb: Use db type preference from ./configure

Use the HDB backend type from the --with-db-type-preference=... option
to ./configure to make the default HDB backend more stable.
---
 lib/hdb/Makefile.am |  1 +
 lib/hdb/hdb.c       | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/lib/hdb/Makefile.am b/lib/hdb/Makefile.am
index 692242323..7ebd4dd08 100644
--- a/lib/hdb/Makefile.am
+++ b/lib/hdb/Makefile.am
@@ -7,6 +7,7 @@ AM_CPPFLAGS += $(INCLUDE_openldap) -DHDB_DB_DIR=\"$(DIR_hdbdir)\"
 AM_CPPFLAGS += -I$(srcdir)/../krb5
 AM_CPPFLAGS += $(INCLUDE_sqlite3)
 AM_CPPFLAGS += $(INCLUDE_libintl)
+AM_CPPFLAGS += -DHDB_DEFAULT_DB_TYPE=\"$(db_type):\"
 if HAVE_DBHEADER
 AM_CPPFLAGS += -I$(DBHEADER)
 endif
diff --git a/lib/hdb/hdb.c b/lib/hdb/hdb.c
index 4934cb1c7..e89c64aa1 100644
--- a/lib/hdb/hdb.c
+++ b/lib/hdb/hdb.c
@@ -802,7 +802,19 @@ hdb_create(krb5_context context, HDB **db, const char *filename)
             *db = NULL;
         }
     }
+#ifdef HDB_DEFAULT_DB_TYPE
+    if (cb_ctx.h == NULL || cb_ctx.h->prefix == NULL) {
+        /*
+         * If still we've not picked a backend, use a build configuration time
+         * default.
+         */
+        for (cb_ctx.h = methods; cb_ctx.h->prefix != NULL; cb_ctx.h++)
+            if (strcmp(cb_ctx.h->prefix, HDB_DEFAULT_DB_TYPE) == 0)
+                break;
+    }
+#endif
     if (cb_ctx.h == NULL || cb_ctx.h->prefix == NULL)
+        /* Last resort default */
         cb_ctx.h = &default_dbmethod;
     if (cb_ctx.h == NULL || cb_ctx.h->prefix == NULL) {
         krb5_set_error_message(context, ENOTSUP,