273357 - [extension/java/xpcom] query interface does not discover interface

Status: RESOLVED FIXED

(Core Graveyard :: Java to XPCOM Bridge, defect)

Description

[Michal Ceresna]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041119 Firefox/1.0 (Debian package 1.0-3)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041119 Firefox/1.0 (Debian package 1.0-3)

This applies to the code in extenstion/java/xpcom

lets have a java-xpcom object implemeted by nsIDOMHTMLButtonElement_Stub.

The corresponding idl hierarchy is:
nsIDOMHTMLButtonElement -> nsIDOMHTMLElement -> nsIDOMNode -> nsISupports

then according to the code in XPCOM.queryInterface
QI to nsIDOMHTMLElement works, but QI to nsIDOMNode does not

because the Class.getInterfaces() returns only parent interfaces
and not all ancestors

Moreover, sometimes I've observed that the aIID parameter to the
XPCOM.queryInterface has the '{' prefix and '}' suffix


Reproducible: Always
Steps to Reproduce:
1.
2.
3.

Comment 1

[Michal Ceresna]

Attachment: proposed fix

Comment 2

[jhp (no longer active)]

Attachment: proposed fix

Newer patch from bug 275359.

Comment 3

[jhp (no longer active)]

Attachment: patch

This is the patch I put together.  The only major difference from your patch is
that I remove the ArrayList elements starting from the front;  this should
speed up the common case, where QI asks for one of the directly implemented
interfaces.

I also removed the code dealign with the brackets in the IID string.  The
string representation of an IID (nsID->ToString()) contains opening and closing
brackets.

The only problem I have with the loop is that the first run through the loop
will try to get the IID for given object, which is unnecessary.  We should just
start with its interfaces and superclass, and go from there.  Haven't found a
nice way to code that yet.

Comment 4

[jhp (no longer active)]

Patch checked into trunk. -> FIXED