On the 1.6.x-svn_fs_commit_txn branch, merge in r1053499 from trunk.

Follow up to r1051988 which had a copy-pasto that has a NULL
deferefence.

* subversion/libsvn_repos/commit.c
  (svn_repos__post_commit_error_str):
    If there is no post-commit hook error, then use the input error,
    not the NULL hook error.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.6.x-svn_fs_commit_txn@1053500 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/subversion/libsvn_repos/commit.c b/subversion/libsvn_repos/commit.c
index e3a3f0c..56bbabf 100644
--- a/subversion/libsvn_repos/commit.c
+++ b/subversion/libsvn_repos/commit.c
@@ -705,8 +705,8 @@
     {
       msg = apr_psprintf(pool,
                          _("post-commit FS processing had error '%s'."),
-                         hook_err2->message ? hook_err2->message
-                                            : _("(no error message)"));
+                         err->message ? err->message
+                                      : _("(no error message)"));
     }
 
   return msg;