Re: GC crashes

[Stefan Monnier]

> If the composition hash table is weak, GC can remove
> key-value pair from the table when a text that contains key
> as `composition' property is deleted (for instance by
> killing a buffer).

I guess strictly speaking, the :weak arg should not be t but `key' so
that only the key part is weak, but that does not explain the crash.

> The crash can be preproduced by this Emacs
>     GNU Emacs 21.3.50.77 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
> by doing this (of course by undoing my fix):

> C-u C-h t thai RET
> C-v (repeatedly until you reach the bottom)
> C-x k RET
> M-x garbage-collect RET
> C-u C-h t thai RET
> C-v (repeatedly)

> You'll encounter segfault before you reach the bottom.

I don't get the crash (with an Emacs checked out two weeks ago from CVS).
Maybe it's because I don't have the relevant fonts ?

> This segfault always happens while marking a buffer that
> contains `composition' property (in the above case, it's
> TUTORIAL.th).  So, I doubted the composition hash table and
> made it strong, then the segfault disappeared.

I suspect your fix just hides the underlying problem.


        Stefan