From d5bc673e319dee589049e374c395e32f50044809 Mon Sep 17 00:00:00 2001
From: Nicolas Williams <nico@twosigma.com>
Date: Sun, 28 Feb 2016 17:54:56 -0600
Subject: [PATCH] Fix HDB two-phase commit for /dev/null log

---
 lib/kadm5/log.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/lib/kadm5/log.c b/lib/kadm5/log.c
index 8a0fcc0b3..31127d413 100644
--- a/lib/kadm5/log.c
+++ b/lib/kadm5/log.c
@@ -897,6 +897,13 @@ kadm5_log_create(kadm5_server_context *context, hdb_entry *entry)
     ent.free_entry = 0;
     ent.entry = *entry;
 
+    /*
+     * If we're not logging then we can't recover-to-perform, so just
+     * perform.
+     */
+    if (strcmp(log_context->log_file, "/dev/null") == 0)
+        return context->db->hdb_store(context->context, context->db, 0, &ent);
+
     /*
      * Test for any conflicting entries before writing the log.  If we commit
      * to the log we'll end-up rolling forward on recovery, but that would be
@@ -982,6 +989,9 @@ kadm5_log_delete(kadm5_server_context *context,
     off_t end_off = 0;  /* Ditto; this allows de-indentation by two levels */
     off_t off;
 
+    if (strcmp(log_context->log_file, "/dev/null") == 0)
+        return context->db->hdb_remove(context->context, context->db, 0,
+                                       princ);
     ret = context->db->hdb_remove(context->context, context->db,
                                   HDB_F_PRECHECK, princ);
     if (ret)
@@ -1088,6 +1098,14 @@ kadm5_log_rename(kadm5_server_context *context,
     ent.free_entry = 0;
     ent.entry = *entry;
 
+    if (strcmp(log_context->log_file, "/dev/null") == 0) {
+        ret = context->db->hdb_store(context->context, context->db, 0, &ent);
+        if (ret == 0)
+            return context->db->hdb_remove(context->context, context->db, 0,
+                                           source);
+        return ret;
+    }
+
     /*
      * Pre-check that the transaction will succeed.
      *
@@ -1243,6 +1261,10 @@ kadm5_log_modify(kadm5_server_context *context,
     ent.free_entry = 0;
     ent.entry = *entry;
 
+    if (strcmp(log_context->log_file, "/dev/null") == 0)
+        return context->db->hdb_store(context->context, context->db,
+                                      HDB_F_REPLACE, &ent);
+
     ret = context->db->hdb_store(context->context, context->db,
                                  HDB_F_PRECHECK | HDB_F_REPLACE, &ent);
     if (ret)
@@ -1598,6 +1620,9 @@ kadm5_log_nop(kadm5_server_context *context, enum kadm_nop_type nop_type)
     kadm5_log_context *log_context = &context->log_context;
     off_t off;
 
+    if (strcmp(log_context->log_file, "/dev/null") == 0)
+        return 0;
+
     off = lseek(log_context->log_fd, 0, SEEK_CUR);
     if (off == -1)
         return errno;