This test is verifying that setting or unsetting an environment
variable in Go via the "os" package makes that change visible to the C
getenv function. The test has been failing on Windows since CL 304569;
it isn't clear to me whether it was running at all before that point.
On Windows the getenv and _putenv C functions are not thread-safe,
so Go's os.Setenv and os.Getenv use the SetEnvironmentVariable and
GetEnvironmentVariable system calls instead. That seems to work fine
in practice; however, changes via SetEnvironmentVariable are
empirically not visible to the C getenv function on certain versions
of Windows.
The MSDN getenv documentation¹ states that ‘getenv operates only on
the data structures accessible to the run-time library and not on the
environment “segment” created for the process by the operating system.
Therefore, programs that use the envp argument to main or wmain may
retrieve invalid information.’ That may be related to what we're
seeing here.
(https://github.com/curl/curl/issues/4774 describes this same behavior
observed in the curl project.)
¹https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/getenv-wgetenv?view=msvc-160#remarks
Updates #36705
Change-Id: I222792f75c650f32c5025b0fa3edab232ff66353
Reviewed-on: https://go-review.googlesource.com/c/go/+/304669
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
This requires us to add a fake argument to issue36705.go so that the
test driver will build it with "go run" rather than "go tool compile".
Change-Id: Id08b97d898ee3e9d6c1fbb072a0a9317ed9faedd
Reviewed-on: https://go-review.googlesource.com/c/go/+/304569
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The wrapper takes a pointer to the argument, not the argument itself.
Fixes#36705
Change-Id: I566d4457d00bf5b84e4a8315a26516975f0d7e10
Reviewed-on: https://go-review.googlesource.com/c/go/+/215942
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
