[SR-10333] Calendar.current.dateComponents([.weekday], from: Date()).weekday segfaults

[weissi]

Previous ID	SR-10333
Radar	None
Original Reporter	@weissi
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	2
Component/s	Foundation
Labels	Bug, 5.0Regression, RunTimeCrash
Assignee	@spevans
Priority	Medium

md5: cb89f104dfb391a44fefac5c708aff9f

Issue Description:

Thanks to mikeisaev (JIRA User) we were just able to reduce the crasher to something really basic. This simple Swift program

Calendar.current.dateComponents([.weekday], from: Date()).weekday

just crashes. The problem is that transitively CFLocaleGetIdentifier gets called with

  1> import Foundation
  2> Calendar.current.dateComponents([.weekday], from: Date()).weekday
Execution interrupted. Enter code to recover and continue.
Enter LLDB commands to investigate (type :help for assistance.)
Process 481 stopped
* thread #​1, name = 'repl_swift', stop reason = signal SIGSEGV: invalid address (fault address: 0x18)
    frame #​0: 0x00007ffff3df8c50 libFoundation.so`CFLocaleGetIdentifier
libFoundation.so`CFLocaleGetIdentifier:
->  0x7ffff3df8c50 <+0>: movq   0x18(%rdi), %rax
    0x7ffff3df8c54 <+4>: retq   
    0x7ffff3df8c55:      nopw   %cs:(%rax,%rax)
    0x7ffff3df8c5f:      nop    
Target 0: (repl_swift) stopped.

[weissi]

@millenomi/@spevans seen anything like this before?

[millenomi]

What version of Swift is this? What is the environment (eg. LANG)?

[swift-ci]

Comment by Mikhail Isaev (JIRA)

lldb version 7.0.0 (git@github.com:apple/swift-lldb.git revision 3d9fc38bfd8cbe56fa4ee3904e996c933566bb08)
Swift-5.0 (revision ba33f9e0b772015326bdecc0d597b2ac9fc61717)
clang revision 5c9d04dc0697297a47b5edb0c1a581b306a42bdb
llvm revision 3207a50965a98cdc2f42a934f158c38182be7257

[swift-ci]

Comment by Mikhail Isaev (JIRA)

Ubuntu 16.04 on DigitalOcean

[weissi]

LANG we saw this with en_US.UTF-8 and POSIX

[weissi]

Thanks @spevans ! #2067

[swift-ci]

Comment by Andrew Theis (JIRA)

To anyone who finds this bug, the workaround is to create your own Calendar instance.