Fix crash in Bigint::New(....), read only digits field was being modified resulting in a crash.

Fix crash in Bigint::New(....), read only digits field was being modified resulting in a crash.

R=regis@google.com

Committed: https://github.com/dart-lang/sdk/commit/ea9e21cc10f0e3a540326fe45c617e011257e37c

[siva, 2016-02-11 23:32:15]

asiva@google.com changed reviewers:
+ regis@google.com

[regis, 2016-02-11 23:38:11]

LGTM with a comment

https://codereview.chromium.org/1685353003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/1685353003/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:17633: // Set leading zero for 64-bit processing of digit
pairs if not set.
I would add a comment explaining that we avoid a write access to a possibly
re-used digit array that could be marked read-only.

[siva, 2016-02-11 23:57:24]

https://codereview.chromium.org/1685353003/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/1685353003/diff/1/runtime/vm/object.cc#newcod...
runtime/vm/object.cc:17633: // Set leading zero for 64-bit processing of digit
pairs if not set.
On 2016/02/11 23:38:11, regis wrote:
> I would add a comment explaining that we avoid a write access to a possibly
> re-used digit array that could be marked read-only.

Done.

[siva, 2016-02-11 23:59:47]

Description was changed from

==========
Fix crash in Bigint::New(....), read only digits field was being modified
resulting in a crash.
==========

to

==========
Fix crash in Bigint::New(....), read only digits field was being modified
resulting in a crash.

R=regis@google.com

Committed:
https://github.com/dart-lang/sdk/commit/ea9e21cc10f0e3a540326fe45c617e011257e37c
==========

[siva, 2016-02-11 23:59:52]

Committed patchset #2 (id:20001) manually as
ea9e21cc10f0e3a540326fe45c617e011257e37c (presubmit successful).