48464 - auto-generated |operator=| interfering with string usage

Status: VERIFIED FIXED

(Core :: XPCOM, defect, P3)

Description

[Scott Collins]

...we didn't notice this until vidur and jst started passing around readable and 
writable references.  We had already noticed this and fixed it (some time ago) in 
|ns[C]String| and subclasses.  The basic problem is that even if you supply 
_other_ |operator=|s, if you don't specifically declare the one that is the copy-
assignment operator, the compiler will auto-generate one for you.  
|nsAReadableString| shouldn't have one at all (since it's immutable).  The one 
that gets generated for |nsAWritableString| does nothing (since writable has no 
concrete state), but that's bad if this one gets picked for an assignment instead 
of one of the ones that does work ... which is what happened.

Comment 1

[Scott Collins]

Attachment: adding appropriate signatures, and commenting things better

Comment 2

[Scott Collins]

this builds and runs in my tests (adding new tests to account for the problem), 
just need r= and a=

Comment 3

[Scott Collins]

the code from the patch is fine, there are a couple of small changes I want to 
make to some of the comments though

Comment 4

[Scott Collins]

Attachment: fixes typos and respects the difference between 'default' and 'auto-generated'

Comment 5

[Scott Collins]

For a= purposes, in case I didn't mention: this bug blocks vidur and jst's work 
on converting the DOM APIs.

Comment 6

[Scott Collins]

fix checked in

Comment 7

[Tracy Walker [:tracy]]

please verify

Comment 8

[leger]

Marking Verified.  Please reopen if problem reoccurs.