data: Added explicit NULL values.

[sysdb.git] / src / core / data.c

diff --git a/src/core/data.c b/src/core/data.c
index 4840736896f55a03b4cf0716e18e3dec7cb9baec..f489367a42218e35a94bbf64afbff7d6255442fb 100644 (file)
--- a/src/core/data.c
+++ b/src/core/data.c
@@ -34,6 +34,8 @@
 #include "core/data.h"
 #include "utils/error.h"
 
+#include <assert.h>
+
 #include <errno.h>
 
 #include <inttypes.h>
@@ -200,21 +202,17 @@ data_concat(const sdb_data_t *d1, const sdb_data_t *d2, sdb_data_t *res)
        else
                return -1;
 
-       if (s1 && s2) {
-               new = malloc(len1 + len2 + 1);
-               if (! new)
-                       return -1;
+       assert(s1 && s2);
 
-               if (len1)
-                       memcpy(new, s1, len1);
-               if (len2)
-                       memcpy(new + len1, s2, len2);
-               new[len1 + len2] = '\0';
-       }
-       else {
-               len1 = len2 = 0;
-               new = NULL;
-       }
+       new = malloc(len1 + len2 + 1);
+       if (! new)
+               return -1;
+
+       if (len1)
+               memcpy(new, s1, len1);
+       if (len2)
+               memcpy(new + len1, s2, len2);
+       new[len1 + len2] = '\0';
 
        res->type = d1->type;
        if (res->type == SDB_TYPE_STRING) {
@@ -231,6 +229,8 @@ data_concat(const sdb_data_t *d1, const sdb_data_t *d2, sdb_data_t *res)
  * public API
  */
 
+const sdb_data_t SDB_DATA_NULL = SDB_DATA_INIT;
+
 int
 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src)
 {
@@ -391,6 +391,8 @@ sdb_data_isnull(const sdb_data_t *datum)
 {
        if (! datum)
                return 1;
+       if (datum->type == SDB_TYPE_NULL)
+               return 1;
        if ((datum->type == SDB_TYPE_STRING) && (! datum->data.string))
                return 1;
        if ((datum->type == SDB_TYPE_BINARY) && (! datum->data.binary.datum))
@@ -424,6 +426,10 @@ sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
 {
        if ((! d1) || (! d2) || (! res))
                return -1;
+       if (sdb_data_isnull(d1) || sdb_data_isnull(d2)) {
+               *res = SDB_DATA_NULL;
+               return 0;
+       }
        switch (op) {
                case SDB_DATA_CONCAT:
                        return data_concat(d1, d2, res);