[vlc-devel] [PATCH 1/4] Fix check for plugin table size

[Rafaël Carré]

Le 31/12/2012 00:12, Cheng Sun a écrit :
> On 30/12/12 22:59, Rafaël Carré wrote:
>> Le 30/12/2012 21:51, Cheng Sun a écrit :
>>> ---
>>>  npapi/support/npunix.cpp | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/npapi/support/npunix.cpp b/npapi/support/npunix.cpp
>>> index 0f4baaf..1f3f778 100644
>>> --- a/npapi/support/npunix.cpp
>>> +++ b/npapi/support/npunix.cpp
>>> @@ -847,7 +847,7 @@ NP_Initialize(NPNetscapeFuncs* nsTable, NPPluginFuncs* pluginFuncs)
>>>              err = NPERR_INCOMPATIBLE_VERSION_ERROR;
>>>          if (nsTable->size < ((char *)&nsTable->posturlnotify - (char *)nsTable))
>>>              err = NPERR_INVALID_FUNCTABLE_ERROR;
>>> -        if (pluginFuncs->size < sizeof(NPPluginFuncs))
>>> +        if (pluginFuncs->size < (char *)&pluginFuncs->setvalue - (char *)pluginFuncs)
>>>              err = NPERR_INVALID_FUNCTABLE_ERROR;
>>>      }
>>
>> What does it fix exactly?
> 
> The NPAPI library version that we've been compiled with might be *more
> recent* than the NPAPI header version of the browser. Which means that
> the pluginFuncs table that we have has more entries in it than the
> browser is expecting. However, NPAPI was designed with
> backwards-compatibility in mind, and when the plugin table is revised by
> Mozilla, new entries are added to the end of the table.
> 
> Before we were asserting that the plugin table that the browser gives us
> to fill in is big enough for the entire table that we've been compiled
> with, but now we check whether the table is just big enough for the
> entries that we actually use.

Thanks,

I think this paragraph definitely has its place in the commit log, don't
be afraid to be too verbose!

(I will let NPAPI experts handle this change though)