nicer double formatting (merge from devbr6)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@33774 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/db/dbmi_base/valuefmt.c

@@ -58,7 +58,7 @@ db_convert_value_to_string(dbValue * value, int sqltype, dbString * string)
 	    sprintf(buf, "%d", db_get_value_int(value));
 	    break;
 	case DB_C_TYPE_DOUBLE:
-	    sprintf(buf, "%.14f", db_get_value_double(value));
+	    sprintf(buf, "%.15g", db_get_value_double(value));
 	    G_trim_decimal(buf);
 	    break;
 	case DB_C_TYPE_STRING: