Re: double free error in gawk

[Andrew J. Schorr]

On Thu, Jul 02, 2020 at 02:17:24PM -0400, Andrew J. Schorr wrote:
> Thanks for finding and fixing it. I had concluded that the problem was in
> fields.c, but I hadn't yet found the time to nail it down.

And thanks for the new -I option. That works nicely in conjuction
with -D to help nail down the bug location:

valgrind ./gawk -D -IMf bug.awk
...
gawk> break 1
...
gawk> run
Starting program:
+ Op_rule
Stopping in BEGIN ...
Breakpoint 1, main() at `bug.awk':2
2               $0 = "a0 b"
gawk> step
...
5               $0 = ""
gawk> step
+ Op_push_i
+ Op_push_i
+ Op_store_field
==14998== Invalid free() / delete / delete[] / realloc()
==14998==    at 0x4C2B06D: free (vg_replace_malloc.c:540)
==14998==    by 0x45DC86: r_unref (node.c:509)
==14998==    by 0x447168: unref (awk.h:1937)
==14998==    by 0x447168: purge_record (field.c:367)
==14998==    by 0x448FDA: reset_record (field.c:342)
...

Regards,
Andy