As of PEAR 1.3.2, the second parameter is a new parameter $level. Any code that relies on $merge being the second parameter will break.
Static version of PEAR_ErrorStack::getErrors() , returns all errors from all singleton stacks.
Set to purge the error stack of existing errors
Level name to check for a particular severity. Use this to determine whether only a particular class of errors has occurred, such as whether any warnings have occurred (errors will be ignored)
Set to return a flat array, not organized by package
Function used to sort a merged array - default sorts by time, and should be good for most cases