[SR-5810] Mutating a Data slice mutates it in a "nuclear fallout" sort of way #3811

CharlesJS · 2017-08-31T23:31:55Z

Environment

Swift version 4.1-dev (LLVM 4b4874ae4e, Clang c57d5b1d41, Swift 4264174392)
Target: x86_64-apple-darwin16.7.0

Additional Detail from JIRA

md5: 09ac1fae4a36088c7c7a7c59395e05ec

Issue Description:

Suppose I have this function. It takes a Data object, makes a mutable copy, appends a byte to the beginning of the copy, and logs the result.

belkadan · 2017-09-01T00:58:33Z

Yikes. Thanks for tracking this down, Charles.

CharlesJS · 2017-09-01T01:28:33Z

I hope my snark wasn't too obnoxious. ;-) I had a bit of fun writing this one.

swift-ci · 2017-09-05T23:14:18Z

Comment by Alexander Belonogov (JIRA)

I submitted a PR with a potential solution to this issue:

CharlesJS · 2017-09-12T20:59:54Z

The bug still seems to occur with the Xcode 9 GM seed (9A235). Please tell me Xcode 9 isn't actually going to ship with this bug in it. :-/

belkadan · 2017-10-12T19:38:45Z

Fixed in apple/swift#11939 also cherry-picked to the swift-4.0-branch.

swift-ci transferred this issue from apple/swift-issues Apr 25, 2022

shahmishal transferred this issue from apple/swift May 5, 2022

This issue was closed.

Provide feedback