database_value_text returns NULL also in PostgreSQL implementation

Author: marcobambini

src/cloudsync.c

@@ -860,8 +860,10 @@ int table_add_stmts (cloudsync_table_context *table, int ncols) {
 cloudsync_table_context *table_lookup (cloudsync_context *data, const char *table_name) {
     DEBUG_DBFUNCTION("table_lookup %s", table_name);
 
-    for (int i=0; i<data->tables_count; ++i) {
-        if ((strcasecmp(data->tables[i]->name, table_name) == 0)) return data->tables[i];
+    if (table_name) {
+        for (int i=0; i<data->tables_count; ++i) {
+            if ((strcasecmp(data->tables[i]->name, table_name) == 0)) return data->tables[i];
+        }
     }
 
     return NULL;

src/dbutils.c

@@ -54,12 +54,18 @@ int dbutils_value_compare (dbvalue_t *lvalue, dbvalue_t *rvalue) {
         case DBTYPE_TEXT: {
             const char *l_text = database_value_text(lvalue);
             const char *r_text = database_value_text(rvalue);
+            if (l_text == NULL && r_text == NULL) return 0;
+            if (l_text == NULL && r_text != NULL) return -1;
+            if (l_text != NULL && r_text == NULL) return 1;
             return strcmp((const char *)l_text, (const char *)r_text);
         } break;
 
         case DBTYPE_BLOB: {
             const void *l_blob = database_value_blob(lvalue);
             const void *r_blob = database_value_blob(rvalue);
+            if (l_blob == NULL && r_blob == NULL) return 0;
+            if (l_blob == NULL && r_blob != NULL) return -1;
+            if (l_blob != NULL && r_blob == NULL) return 1;
             int l_size = database_value_bytes(lvalue);
             int r_size = database_value_bytes(rvalue);
             int cmp = memcmp(l_blob, r_blob, (l_size < r_size) ? l_size : r_size);

src/postgresql/database_postgresql.c

@@ -2203,7 +2203,7 @@ int64_t database_value_int (dbvalue_t *value) {
 
 const char *database_value_text (dbvalue_t *value) {
     pgvalue_t *v = (pgvalue_t *)value;
-    if (!v || v->isnull) return "";
+    if (!v || v->isnull) return NULL;
 
     if (!v->cstring) {
         PG_TRY();

src/sqlite/cloudsync_sqlite.c

@@ -199,6 +199,10 @@ void dbsync_col_value (sqlite3_context *context, int argc, sqlite3_value **argv)
 
     // retrieve column name
     const char *col_name = (const char *)database_value_text(argv[1]);
+    if (!col_name) {
+        dbsync_set_error(context, "Column name cannot be NULL");
+        return;
+    }
 
     // check for special tombstone value
     if (strcmp(col_name, CLOUDSYNC_TOMBSTONE_VALUE) == 0) {