// PTAL. Pretty sure I reported that already, but couldn't find it now. Repros with fullcode/default - crankshaft issue? Minimized:

function foo(a, i) {
  var v = [0.5,,][i];
  if (i == 0) {
    v = 2;
  }
  a[v] = 1;
}

a = new Int32Array(2);
foo(a, 0);
%OptimizeFunctionOnNextCall(foo);
foo(a, 1);
print(a[undefined]);

//Output:
# Compared x64,fullcode with x64,default
#
# Flags of x64,fullcode:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --random-seed 1474417455 --nocrankshaft --turbo-filter=~ --validate-asm
# Flags of x64,default:
--abort_on_stack_overflow --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --random-seed 1474417455 --validate-asm
#
# Difference:
- 1
+ undefined
#
# Source file:
none
#
### Start of configuration x64,fullcode:
1

### End of configuration x64,fullcode
#
### Start of configuration x64,default:
undefined

### End of configuration x64,default

Looks like a Crankshaft issue.

ClusterFuzz has detected this issue as fixed in range 43683:43684.

Detailed report: https://clusterfuzz.com/testcase?key=5307106610905088

Fuzzer: foozzie_js_mutation
Job Type: foozzie_ignition_staging
Platform Id: linux

Crash Type: V8 correctness failure
Crash Address: 
Crash State:
  configs: x64,fullcode:x64,ignition_staging
  sources: 5fb
  
Sanitizer: address (ASAN)

Regressed: V8: 42370:42371
Fixed: V8: 43683:43684

Reproducer Testcase: https://clusterfuzz.com/download/AMIfv97Dau_42w6znBLBdj6_Kj9YZN08UuEdQXZ8bLKQHkR92rXW_ANELYKkeAKxcfq1gvJJE4PGt7KOt9JObsS8ogKGevW8oMOX6E-z82pSXsz5MAVqGElYnCeDTzg3FGXaQ9TU25mOieLYymsa8feHTEiQyUOUfa2TBtg7HyfLteE-7ZELpLeLPqHozxL3ZEj0uxhuhlZsAKT9U1RgXZ-GcULWrlXwT1-g2Wd28T_JW5-qc9fpMYDa3NLVRpSMtet-7m8HKFJomiyin8PGtwSKixxOSYDPD2XtFa5sMs0XNJvlIbNddryCBfgTazY4fPCPH2snnv7tPBZDNE7Ql8JXrM9oeX1k8jZCXiY9lxNZvt5Mx5rJbYY?testcase_id=5307106610905088


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.

ClusterFuzz testcase 5307106610905088 is verified as fixed, so closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.