[PATCH 7/8] mshtml: Check for valid XML Content-Type for responseXML in IE10+ modes.

[Gabriel Ivăncescu]

On 07/06/2022 20:16, Jacek Caban wrote:
> On 6/6/22 20:21, Gabriel Ivăncescu wrote:
>> On 06/06/2022 20:40, Jacek Caban wrote:
>>> On 6/6/22 14:24, Gabriel Ivăncescu wrote:
>>>> For some reason, Gecko returns an XML document here, but native follows
>>>> the spec.
>>>
>>>
>>> That doesn't really make sense, Gecko is not involved because we 
>>> currently use msxml instead of Gecko here. I guess you're referring 
>>> to your future patches, in which case the question is what's "some 
>>> reason"? Looking at Gecko sources, it returns XML document only for 
>>> XML_HTTP_RESPONSE_TYPE_DEFAULT and XML_HTTP_RESPONSE_TYPE_DOCUMENT 
>>> response type. What's wrong with that?
>>>
>>>
>>> Similar question applies to overrideMimeType, why can't we let Gecko 
>>> handle that?
>>>
>>>
>>> Jacek
>>>
>>
>> I meant if we use Gecko's responseXML to check whether it's NULL or 
>> not. For "default" case (no override), Gecko returns a non-NULL xml 
>> doc, even if Content-Type is not valid the way IE treats it. So we 
>> can't use it to check this (I tried it first since it's simpler).
>>
>> It does do the right thing with overrideMimeType, but if we use it, 
>> we'll override *any* content type, which is not good either. Well at 
>> least not good enough to match native IE. 
> 
> 
> The whole thing seems to me like working around a problem somewhere 
> else. My guess would be nsio.c, which has hacks for things like 
> GetContentType(), but it's hard to tell without looking deeper.  Did you 
> rule that out somehow?
> 
> 
> Jacek
> 

I haven't looked into that, I wasn't aware it affects XMLHttpRequests. 
Skimming through it, it doesn't look like it would affect it (text/html 
is invalid in IE, not sure if Gecko treats it as valid XML to parse), 
but I'll investigate it more tomorrow.