db_text: fix computing absolute path to db using cfg dir

- reported by GH #1224

src/modules/db_text/dbt_base.c

@@ -52,6 +52,7 @@ db1_con_t* dbt_init(const str* _sqlurl)
 		LM_ERR("invalid parameter value\n");
 		return NULL;
 	}
+	LM_DBG("initializing for db url: [%.*s]\n", _sqlurl->len, _sqlurl->s);
 	_s.s = _sqlurl->s;
 	_s.len = _sqlurl->len;
 	if(_s.len <= DBT_ID_LEN || strncmp(_s.s, DBT_ID, DBT_ID_LEN)!=0)
@@ -68,16 +69,22 @@ db1_con_t* dbt_init(const str* _sqlurl)
 	_s.len -= DBT_ID_LEN;
 	if(_s.s[0]!='/')
 	{
-		if(sizeof(CFG_DIR)+_s.len+2 > DBT_PATH_LEN)
+		if(sizeof(CFG_DIR)+_s.len+2 >= DBT_PATH_LEN)
 		{
 			LM_ERR("path to database is too long\n");
 			return NULL;
 		}
 		strcpy(dbt_path, CFG_DIR);
-		dbt_path[sizeof(CFG_DIR)] = '/';
-		strncpy(&dbt_path[sizeof(CFG_DIR)+1], _s.s, _s.len);
-		_s.len += sizeof(CFG_DIR);
+		if(dbt_path[sizeof(CFG_DIR)-2]!='/') {
+			dbt_path[sizeof(CFG_DIR)-1] = '/';
+			strncpy(&dbt_path[sizeof(CFG_DIR)], _s.s, _s.len);
+			_s.len += sizeof(CFG_DIR);
+		} else {
+			strncpy(&dbt_path[sizeof(CFG_DIR)-1], _s.s, _s.len);
+			_s.len += sizeof(CFG_DIR) - 1;
+		}
 		_s.s = dbt_path;
+		LM_DBG("updated db url: [%.*s]\n", _s.len, _s.s);
 	}
 
 	_res = pkg_malloc(sizeof(db1_con_t)+sizeof(dbt_con_t));

src/modules/db_text/dbt_file.c

@@ -94,14 +94,15 @@ dbt_table_p dbt_load_file(const str *tbn, const str *dbn)
 
 	enum {DBT_FLINE_ST, DBT_NLINE_ST, DBT_DATA_ST} state;
 
-	LM_DBG("request for table [%.*s]\n", tbn->len, tbn->s);
-
 	if(!tbn || !tbn->s || tbn->len<=0 || tbn->len>=255)
 		return NULL;
+
+	LM_DBG("request for table [%.*s] (len: %d)\n", tbn->len, tbn->s, tbn->len);
+
 	path[0] = 0;
 	if(dbn && dbn->s && dbn->len>0)
 	{
-		LM_DBG("db is [%.*s]\n", dbn->len, dbn->s);
+		LM_DBG("db is [%.*s] (len: %d)\n", dbn->len, dbn->s, dbn->len);
 		if(dbn->len+tbn->len<511)
 		{
 			strncpy(path, dbn->s, dbn->len);
@@ -118,8 +119,10 @@ dbt_table_p dbt_load_file(const str *tbn, const str *dbn)
 
 	LM_DBG("loading file [%s]\n", path);
 	fin = fopen(path, "rt");
-	if(!fin)
+	if(!fin) {
+		LM_ERR("failed to open file [%s]\n", path);
 		return NULL;
+	}
 
 	buf = pkg_malloc(_db_text_read_buffer_size);
 	if(!buf) {