Merge branch '81135'

* 81135:
  Fix #81135 unknown help topic in phpdbg fails assertion

Author: krakjoe

NEWS

@@ -8,6 +8,9 @@ PHP                                                                        NEWS
 - PDO OCI:
   . Fixed bug #77120 (Support 'success with info' at connection).
     (Sergei Morozov)
+    
+- phpdbg:
+  . Fixed bug #81135 (unknown help topic causes assertion failure). (krakjoe)
 
 10 Jun 2021, PHP 8.1.0alpha1
 

sapi/phpdbg/phpdbg_help.c

@@ -263,6 +263,8 @@ PHPDBG_COMMAND(help) /* {{{ */
 					pretty_print(get_help(cmd->name));
 					return SUCCESS;
 				}
+			} else {
+			    phpdbg_error("No help topic found for %s", param->str);
 			}
 		}
 	}

sapi/phpdbg/phpdbg_prompt.c

@@ -1558,7 +1558,9 @@ int phpdbg_interactive(bool allow_async_unsafe, char *input) /* {{{ */
 				case FAILURE:
 					if (!(PHPDBG_G(flags) & PHPDBG_IS_STOPPING)) {
 						if (!allow_async_unsafe || phpdbg_call_register(&stack) == FAILURE) {
-							phpdbg_output_err_buf("%b");
+							if (PHPDBG_G(err_buf).active) {
+							    phpdbg_output_err_buf("%b");
+							}
 						}
 					}
 				break;

sapi/phpdbg/tests/bug81135.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Bug #81135: unknown help topic fails assertion
+--PHPDBG--
+help unknown
+q
+--FILE--
+<?php
+
+?>
+--EXPECTF--
+[Successful compilation of %sbug81135.php]
+prompt> [No help topic found for unknown]
+prompt>