From 7649cd039c4ca73698403baf1bc6c3cad4af8301 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Sun, 5 Oct 2014 20:25:32 +0200
Subject: [PATCH] data: Added sdb_data_isnull().

The function determines if a datum pointer or a string or binary datum is
NULL.
---
 src/core/data.c         | 12 ++++++++++++
 src/include/core/data.h |  8 ++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/core/data.c b/src/core/data.c
index a57c8c6..eeead55 100644
--- a/src/core/data.c
+++ b/src/core/data.c
@@ -334,6 +334,18 @@ sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2)
 #undef CMP_NULL
 } /* sdb_data_cmp */
 
+_Bool
+sdb_data_isnull(const sdb_data_t *datum)
+{
+	if (! datum)
+		return 1;
+	if ((datum->type == SDB_TYPE_STRING) && (! datum->data.string))
+		return 1;
+	if ((datum->type == SDB_TYPE_BINARY) && (! datum->data.binary.datum))
+		return 1;
+	return 0;
+} /* sdb_data_isnull */
+
 int
 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
 		sdb_data_t *res)
diff --git a/src/include/core/data.h b/src/include/core/data.h
index 02f99c5..af4ae5a 100644
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
@@ -115,6 +115,14 @@ sdb_data_free_datum(sdb_data_t *datum);
 int
 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
 
+/*
+ * sdb_data_isnull:
+ * Determine whether a datum is NULL. A datum is considered to be NULL if
+ * either datum is NULL or if the string or binary datum is NULL.
+ */
+_Bool
+sdb_data_isnull(const sdb_data_t *datum);
+
 /*
  * Operators supported by sdb_data_eval_expr.
  */
-- 
2.30.2