Partially fix bug #67167 - Wrong return value...

...from FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE

The remainer of the fix would require the filter functions to only
convert to string when it makes sense for that particular filter.

Author: morrisonlevi

ext/filter/filter.c

@@ -389,7 +389,12 @@ static void php_zval_filter(zval *value, zend_long filter, zend_long flags, zval
 		ce = Z_OBJCE_P(value);
 		if (!ce->__tostring) {
 			zval_ptr_dtor(value);
-			ZVAL_FALSE(value);
+			/* #67167: doesn't return null on failure for objects */
+			if (flags & FILTER_NULL_ON_FAILURE) {
+				ZVAL_NULL(value);
+			} else {
+				ZVAL_FALSE(value);
+			}
 			return;
 		}
 	}

ext/filter/tests/bug67167.01.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Bug #67167: object with VALIDATE_BOOLEAN and NULL_ON_FAILURE
+
+--SKIPIF--
+<?php if (!extension_loaded("filter")) die("skip"); ?>
+
+--FILE--
+<?php
+var_dump(filter_var(
+    new \StdClass(),
+    FILTER_VALIDATE_BOOLEAN,
+    FILTER_NULL_ON_FAILURE
+));
+
+--EXPECTF--
+NULL

ext/filter/tests/bug67167.02.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Bug #67167: filter_var(null,FILTER_VALIDATE_BOOLEAN,FILTER_NULL_ON_FAILURE) returns null
+
+--SKIPIF--
+<?php if (!extension_loaded("filter")) die("skip"); ?>
+
+--FILE--
+<?php
+var_dump(filter_var(
+    null,
+    FILTER_VALIDATE_BOOLEAN,
+    FILTER_NULL_ON_FAILURE
+));
+
+--XFAIL--
+Requires php_zval_filter to not use convert_to_string for all filters.
+
+--EXPECTF--
+NULL
+