114961 - assertion when looking up OS native mime types

Status: VERIFIED FIXED

(Core Graveyard :: File Handling, defect)

Description

[Scott MacGregor]

I'm getting a lot of assertions in todays build whenever we try to look up the
content type for a file extension which is defined in the OS (and not in our
data source). 

The problem is coming from:
nsExternalHelperAppService::GetMIMEInfoForExtensionFromDS. It calls
mOverRideDataSource->GetSource which returns NS_RDF_NO_VALUE. However apparently
this does not qualify as an error code. So the subsequent if (NS_SUCCEEDED(rv))
gets executed. So we end up asserting in FillLiteralValueFromTarget because we
have a null resource node.

we might want to expand the if check to include a null check for
contentTypeNodeResource

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: proposed patch

Comment 2

[Boris Zbarsky [:bzbarsky]]

Attachment: Same as diff -uw

Comment 3

[Boris Zbarsky [:bzbarsky]]

To law for now; by the time the tree opens I will be able to neither build nor
check in, since my computer will be off and I'll be 400 miles from it (till
early January).

Comment 4

[Scott MacGregor]

Comment on attachment 61530 [details] [diff] [review]
Same as diff -uw

sr=mscott

but we should probably make sure *aMIMEInfo is initialized to null at the top
of the routine too.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Attachment: Same but set *aMimeInfo to null

Comment 6

[Scott MacGregor]

Comment on attachment 61532 [details] [diff] [review]
Same but set *aMimeInfo to null

sr=mscott

I'm already running with this patch. If Bill doesn't mind I'm going to check it
in today.

Comment 7

[Scott MacGregor]

I just checked this in so we can stop getting these assertions. 

Comment 8

[sairuh (rarely reading bugmail)]

mscott, did you see this only debug builds, or was it also cropping up in verif
builds?

Comment 9

[Scott MacGregor]

this was debug only. I'll go ahead and mark it verified for ya.