41864 - ECMA function call incompatibility

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Waldemar Horwat]

name='win';
obj1={name:'obj1'};
obj1.f=function(){alert(this.name)}
obj2={name:'obj2'};
(obj2.f=obj1.f)();

(replace 'alert' with 'print' in JSRef).

The code above should print 'win'.  It prints 'obj2'.
Another test case is:

(obj2.f,obj1.f)();

This should also print 'win'.  It prints 'obj1'.

The reason is as follows:

Step 3 of ECMA 11.13.1 calls GetValue, which turns a reference to a regular 
value.  That value is then returned in step 5.  A function call (section 11.2.3) 
looks to see if the function is a reference or a regular value.  If it's a 
reference then it extracts its base and assigns it to the "this" variable.  If 
it's a regular value, then the "this" variable becomes null (step 6 of 11.2.3).  
The [[call]] method then changes "this" to point to the global object (the last 
paragraph of 10.2.3).  That's why this.name should be 'win'.

Comment 1

[Brendan Eich [:brendan]]

Adding js1.5.  Patch coming up.

/be

Comment 2

[Brendan Eich [:brendan]]

Adding more JS1.5 buddies.

/be

Comment 3

[Brendan Eich [:brendan]]

Attachment: proposed fix

Comment 4

[Brendan Eich [:brendan]]

Fix checked in.  Thanks pschwartau for the thumbs-up regression testing.

/be