runtime: fix TestFixedGOROOT to properly restore the GOROOT env var after test

Otherwise subsequent tests won't see any modified GOROOT.

With this CL I can move my GOROOT, set GOROOT to the new location, and
the runtime tests pass. Previously the crash_tests would instead look
for the GOROOT baked into the binary, instead of the env var:

--- FAIL: TestGcSys (0.01s)
        crash_test.go:92: building source: exit status 2
                go: cannot find GOROOT directory: /home/bradfitz/go
--- FAIL: TestGCFairness (0.01s)
        crash_test.go:92: building source: exit status 2
                go: cannot find GOROOT directory: /home/bradfitz/go
--- FAIL: TestGdbPython (0.07s)
        runtime-gdb_test.go:64: building source exit status 2
                go: cannot find GOROOT directory: /home/bradfitz/go
--- FAIL: TestLargeStringConcat (0.01s)
        crash_test.go:92: building source: exit status 2
                go: cannot find GOROOT directory: /home/bradfitz/go

Update #10029

Change-Id: If91be0f04d3acdcf39a9e773a4e7905a446bc477
Reviewed-on: https://go-review.googlesource.com/10685
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/runtime/env_test.go b/src/runtime/env_test.go
index 203f38065d5f6d4fb8b0ff16d4e2ca96ccf50df8..2399e46faa91e8bc850aa5e303687d7128ca0f35 100644 (file)
--- a/src/runtime/env_test.go
+++ b/src/runtime/env_test.go
@@ -15,6 +15,12 @@ func TestFixedGOROOT(t *testing.T) {
                t.Skipf("skipping plan9, it is inconsistent by allowing GOROOT to be updated by Setenv")
        }
 
+       // Restore both the real GOROOT environment variable, and runtime's copies:
+       if orig, ok := syscall.Getenv("GOROOT"); ok {
+               defer syscall.Setenv("GOROOT", orig)
+       } else {
+               defer syscall.Unsetenv("GOROOT")
+       }
        envs := runtime.Envs()
        oldenvs := append([]string{}, envs...)
        defer runtime.SetEnvs(oldenvs)