External Libraries: Skip instanceof check when null in Text_Diff::_check().

On the first `foreach` loop in Text_Diff::_check()`, `$prevtype` is `null`. As `instanceof` requires the class name term to be an object or string, a fatal error is thrown:

>Fatal error: Uncaught Error: Class name must be a valid object or a string on line 279

This change:
* Adds a simple test for the `Text_Diff::_check()` method, which is how the bug was discovered as the test could never pass with the code as-is.

* Adds a defensive guard to protect against the fatal. It checks if `$prevtype` is not `null` as a pre-condition to for checking the instance. This bugfix also resolves the failing test.

Follow-up to [49194], [7747].

Props jrf, hellofromTonya.
See #62083.
Built from https://develop.svn.wordpress.org/trunk@59070


git-svn-id: http://core.svn.wordpress.org/trunk@58466 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
hellofromTonya 2024-09-19 20:22:15 +00:00
parent b58cc4d2b0
commit 4ab4b38ecd
2 changed files with 2 additions and 2 deletions

View File

@ -276,7 +276,7 @@ class Text_Diff {
$prevtype = null; $prevtype = null;
foreach ($this->_edits as $edit) { foreach ($this->_edits as $edit) {
if ($edit instanceof $prevtype) { if ($prevtype !== null && $edit instanceof $prevtype) {
trigger_error("Edit sequence is non-optimal", E_USER_ERROR); trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
} }
$prevtype = get_class($edit); $prevtype = get_class($edit);

View File

@ -16,7 +16,7 @@
* *
* @global string $wp_version * @global string $wp_version
*/ */
$wp_version = '6.7-alpha-59069'; $wp_version = '6.7-alpha-59070';
/** /**
* Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema. * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.