Fix bug #60768 Output buffer not discarded

in php_output_handler_op():
  * if appending to buffer succeeds, just return HANDLER_NO_DATA
    and do nothing else
  * if a zero sized string or true is returned from the handler
    function, reset the context as well as the handler's buffer

main/output.c

@@ -885,7 +885,8 @@ static inline php_output_handler_status_t php_output_handler_op(php_output_handl
 
 	/* storable? */
 	if (php_output_handler_append(handler, &context->in TSRMLS_CC) && !context->op) {
-		status = PHP_OUTPUT_HANDLER_NO_DATA;
+		context->op = original_op;
+		return PHP_OUTPUT_HANDLER_NO_DATA;
 	} else {
 		/* need to start? */
 		if (!(handler->flags & PHP_OUTPUT_HANDLER_STARTED)) {
@@ -961,13 +962,13 @@ static inline php_output_handler_status_t php_output_handler_op(php_output_handl
 			handler->buffer.used = 0;
 			handler->buffer.size = 0;
 			break;
-		case PHP_OUTPUT_HANDLER_SUCCESS:
-			/* no more buffered data */
-			handler->buffer.used = 0;
-			break;
 		case PHP_OUTPUT_HANDLER_NO_DATA:
 			/* handler ate all */
 			php_output_context_reset(context);
+			/* no break */
+		case PHP_OUTPUT_HANDLER_SUCCESS:
+			/* no more buffered data */
+			handler->buffer.used = 0;
 			break;
 	}
 

tests/output/bug60768.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Bug #60768 Output buffer not discarded
+--FILE--
+<?php
+
+global $storage;
+
+ob_start(function($buffer) use (&$storage) { $storage .= $buffer; }, 20);
+
+echo str_repeat("0", 20); // fill in the buffer
+
+for($i = 0; $i < 10; $i++) {
+    echo str_pad($i, 9, ' ', STR_PAD_LEFT) . "\n"; // full buffer dumped every time
+}
+
+ob_end_flush();
+
+printf("Output size: %d, expected %d\n", strlen($storage), 20 + 10 * 10);
+
+?>
+DONE
+--EXPECT--
+Output size: 120, expected 120
+DONE
+