Fix error messages

Author: kamil-tekiela

ext/mysqli/mysqli_nonapi.c

@@ -453,8 +453,8 @@ PHP_FUNCTION(mysqli_fetch_column)
 		zend_argument_value_error(ERROR_ARG_POS(2), "must be greater than or equal to 0");
 		RETURN_THROWS();
 	}
-	if(col_no >= result->field_count) {
-		zend_value_error("Invalid column index");
+	if (col_no >= mysql_num_fields(result)) {
+		zend_argument_value_error(ERROR_ARG_POS(2), "must be less than the number of fields for this result set");
 		RETURN_THROWS();
 	}
 

ext/mysqli/tests/mysqli_class_mysqli_result_interface.phpt

@@ -35,6 +35,7 @@ require_once('skipifconnectfailure.inc');
         'fetch_fields'          => true,
         'fetch_object'          => true,
         'fetch_row'             => true,
+        'fetch_column'          => true,
         'field_seek'            => true,
         'free'                  => true,
         'free_result'           => true,

ext/mysqli/tests/mysqli_fetch_column.phpt

@@ -121,7 +121,7 @@ int(1)
 [008]
 mysqli_fetch_column(): Argument #2 ($column) must be greater than or equal to 0
 [009]
-Invalid column index
+mysqli_fetch_column(): Argument #2 ($column) must be less than the number of fields for this result set
 mysqli_result object is already closed
 [010]
 int(1)