// PTAL. Looks like a turbofan bug:

function baz(name) {
  print(this[name]);
}
baz();
baz();
%OptimizeFunctionOnNextCall(baz)
Object.defineProperty(this, 'b', { value: 0 });
baz('b');

// Output:
# Compared x64,ignition with x64,ignition_turbo
#
# Flags of x64,ignition:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --random-seed 1234 --ignition --turbo-filter=~ --hydrogen-filter=~ --validate-asm --nocrankshaft
# Flags of x64,ignition_turbo:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --random-seed 1234 --ignition-staging --turbo --validate-asm
#
# Difference:
- 0
+ undefined
#
# Source file:
none
#
### Start of configuration x64,ignition:
undefined
undefined
0

### End of configuration x64,ignition
#
### Start of configuration x64,ignition_turbo:
undefined
undefined
undefined

### End of configuration x64,ignition_turbo

Interesting, I'll investigate ...

Thanks

Missing name check in {JSNativeContextSpecialization::ReduceNamedAccess} when targeting the global object. Cooking up a fix.

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/875ccb48fff41b6c41d3b5f193ddfdd87ec4bb6d

commit 875ccb48fff41b6c41d3b5f193ddfdd87ec4bb6d
Author: Michael Starzinger <mstarzinger@chromium.org>
Date: Tue Feb 21 14:51:07 2017

[turbofan] Fix missing name check for keyed global load.

This fixes a missing name check for keyed property loads targeting the
global object where the feedback was warmed up with a single name. This
affects {JSLoadProperty} nodes only, syntactic global property loads via
the {JSLoadGlobal} operator are not affected.

R=bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-694416
BUG= chromium:694416 

Change-Id: I54aa3f27eaa72630539f02602ec7642b04835b27
Reviewed-on: https://chromium-review.googlesource.com/445224
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43344}
[modify] https://crrev.com/875ccb48fff41b6c41d3b5f193ddfdd87ec4bb6d/src/compiler/js-native-context-specialization.cc
[modify] https://crrev.com/875ccb48fff41b6c41d3b5f193ddfdd87ec4bb6d/src/compiler/js-native-context-specialization.h
[add] https://crrev.com/875ccb48fff41b6c41d3b5f193ddfdd87ec4bb6d/test/mjsunit/regress/regress-crbug-694416.js

 Issue 687448  has been merged into this issue.

ClusterFuzz has detected this issue as fixed in range 43343:43344.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=6715522436825088

Fuzzer: foozzie_js_mutation
Job Type: v8_foozzie
Platform Id: linux

Crash Type: V8 correctness failure
Crash Address: 
Crash State:
  configs: x64,ignition:x64,ignition_turbo_opt
  sources: 9d9
  
Sanitizer: address (ASAN)

Fixed: V8: 43343:43344

Reproducer Testcase: https://cluster-fuzz.appspot.com/download/AMIfv94k9d8eL4ztLd0VzpMeiHsrPmcFIUtrWkn43p9Z5Rjo2OqLAN5iiqV7UcH2d6lYOXgxVLxCY9l28EIUZiKnkHCuK2M8NRgh965n3cuhGdBX2yUpH3WatIYwfKRH5fcIN05igR8uNV6Dhv3eyFIQoApc0sQwy965f5Ph7wNuEanV5Me7HVDQPcbED09_xt1rkjm47p5hPNHPQ7ugOeF6kMgmLc7OiXp8GZLXGMqpfJWXeediMSk_ku2FANO_cSSLgaiTZCvwURU8DQdImoaqzfKYSuwCZF4VGia4mReBBNfD7NUB6Cn2eye70m0WqaVuWuLSarQRzXZhVJfoIYf71mJ_nAHFczmzFfHUOFS0V9VG5JDz3QoZuz64kqPj4otRg-7tOUsX75BzSlmhflOk1hjBW17ksg?testcase_id=6715522436825088


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.