Fix GH-19300: Nested array_multisort invocations break

ext/standard/array.c

@@ -5911,7 +5911,7 @@ PHP_FUNCTION(array_multisort)
 	for (i = 0; i < MULTISORT_LAST; i++) {
 		parse_state[i] = 0;
 	}
-	func = ARRAYG(multisort_func) = ecalloc(argc, sizeof(bucket_compare_func_t));
+	func = ecalloc(argc, sizeof(bucket_compare_func_t));
 
 	/* Here we go through the input arguments and parse them. Each one can
 	 * be either an array or a sort flag which follows an array. If not
@@ -5927,7 +5927,7 @@ PHP_FUNCTION(array_multisort)
 			/* We see the next array, so we update the sort flags of
 			 * the previous array and reset the sort flags. */
 			if (i > 0) {
-				ARRAYG(multisort_func)[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
+				func[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
 				sort_order = PHP_SORT_ASC;
 				sort_type = PHP_SORT_REGULAR;
 			}
@@ -5979,8 +5979,6 @@ PHP_FUNCTION(array_multisort)
 			MULTISORT_ABORT;
 		}
 	}
-	/* Take care of the last array sort flags. */
-	ARRAYG(multisort_func)[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
 
 	/* Make sure the arrays are of the same size. */
 	array_size = zend_hash_num_elements(Z_ARRVAL_P(arrays[0]));
@@ -5998,6 +5996,11 @@ PHP_FUNCTION(array_multisort)
 		RETURN_TRUE;
 	}
 
+	/* Take care of the last array sort flags. */
+	func[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
+	bucket_compare_func_t *old_multisort_func = ARRAYG(multisort_func);
+	ARRAYG(multisort_func) = func;
+
 	/* Create the indirection array. This array is of size MxN, where
 	 * M is the number of entries in each input array and N is the number
 	 * of the input arrays + 1. The last column is UNDEF to indicate the end
@@ -6074,6 +6077,7 @@ PHP_FUNCTION(array_multisort)
 	efree(indirect);
 	efree(func);
 	efree(arrays);
+	ARRAYG(multisort_func) = old_multisort_func;
 }
 /* }}} */
 

ext/standard/tests/array/gh19300_1.phpt

@@ -0,0 +1,40 @@
+--TEST--
+GH-19300 (Nested array_multisort invocation with error breaks) - correct invocation variation
+--FILE--
+<?php
+class MyStringable {
+    public function __construct(private string $data) {}
+    public function __tostring() {
+        array_multisort([]); // Trigger update of array sort globals in happy path
+        return $this->data;
+    }
+}
+
+$inputs = [
+    new MyStringable('3'),
+    new MyStringable('1'),
+    new MyStringable('2'),
+];
+
+var_dump(array_multisort($inputs, SORT_STRING));
+var_dump($inputs);
+?>
+--EXPECT--
+bool(true)
+array(3) {
+  [0]=>
+  object(MyStringable)#2 (1) {
+    ["data":"MyStringable":private]=>
+    string(1) "1"
+  }
+  [1]=>
+  object(MyStringable)#3 (1) {
+    ["data":"MyStringable":private]=>
+    string(1) "2"
+  }
+  [2]=>
+  object(MyStringable)#1 (1) {
+    ["data":"MyStringable":private]=>
+    string(1) "3"
+  }
+}

ext/standard/tests/array/gh19300_2.phpt

@@ -0,0 +1,40 @@
+--TEST--
+GH-19300 (Nested array_multisort invocation with error breaks) - error variation
+--FILE--
+<?php
+
+function error_handle($level, $message, $file = '', $line = 0){
+    try {
+        array_multisort($a, SORT_ASC); // Trigger multisort abort
+    } catch (TypeError $e) {
+        echo $e->getMessage(), "\n";
+    }
+}
+set_error_handler('error_handle');
+
+$inputs = [
+    new stdClass,
+    new stdClass,
+    new stdClass,
+];
+
+var_dump(array_multisort($inputs, SORT_NUMERIC));
+var_dump($inputs);
+?>
+--EXPECT--
+array_multisort(): Argument #1 ($array) must be an array or a sort flag
+array_multisort(): Argument #1 ($array) must be an array or a sort flag
+array_multisort(): Argument #1 ($array) must be an array or a sort flag
+array_multisort(): Argument #1 ($array) must be an array or a sort flag
+bool(true)
+array(3) {
+  [0]=>
+  object(stdClass)#1 (0) {
+  }
+  [1]=>
+  object(stdClass)#2 (0) {
+  }
+  [2]=>
+  object(stdClass)#3 (0) {
+  }
+}