The array_product() function is completely broken. I've filed a bug at
http://bugs.php.net/bug.php?id=35014 describing the problem, but to summarise
it returns 0 for all valid input and when the input is an empty array.

I've also posted a patch, which fixes everything for me. I would appreciate
any feedback, especially since this is my first patch :)

Thanks,
Arpad Ray

Index: ext/standard/array.c

RCS file: /repository/php-src/ext/standard/array.c,v
retrieving revision 1.308.2.10
diff -u -u -b -B -r1.308.2.10 array.c
--- ext/standard/array.c 28 Oct 2005 09:57:35 -0000 1.308.2.10
+++ ext/standard/array.c 29 Oct 2005 06:04:22 -0000
@@ -3997,7 +3997,12 @@
return;
}

•   ZVAL_LONG(return_value, 0);
  

•   if (zend_hash_num_elements(Z_ARRVAL_PP(input)) == 0) {
  

•           php_error_docref(NULL TSRMLS_CC, E_WARNING, "Array must 
  

contain at least one element");

•           return;
  

•   }
  

•   ZVAL_LONG(return_value, 1);
  
    for (zend_hash_internal_pointer_reset_ex(Z_ARRVAL_PP(input), &pos);
             zend_hash_get_current_data_ex(Z_ARRVAL_PP(input), (void 
  

**)&entry, &pos) == SUCCESS;