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author | Bryan C. Mills <bcmills@google.com> | 2022-04-20 17:07:14 -0400 |
---|---|---|
committer | Gopher Robot <gobot@golang.org> | 2022-04-21 17:37:05 +0000 |
commit | b34838913da606087b0f3141891f7d0fb2254eef (patch) | |
tree | e82ffa5fd4b077814e4d2fe55ca399325f6b81ff /src/os/exec/exec_posix_test.go | |
parent | 115852077f45141b293727558e61c0804661d328 (diff) | |
download | go-b34838913da606087b0f3141891f7d0fb2254eef.tar.gz go-b34838913da606087b0f3141891f7d0fb2254eef.zip |
os/exec: set PWD implicitly if Dir is non-empty and Env is nil
Fixes #50599.
Change-Id: I4e5dbb3972cdf21ede049567bfb98f2c992c5849
Reviewed-on: https://go-review.googlesource.com/c/go/+/401340
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Diffstat (limited to 'src/os/exec/exec_posix_test.go')
-rw-r--r-- | src/os/exec/exec_posix_test.go | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/os/exec/exec_posix_test.go b/src/os/exec/exec_posix_test.go index ce83a9e4b3..a0880c43ed 100644 --- a/src/os/exec/exec_posix_test.go +++ b/src/os/exec/exec_posix_test.go @@ -7,9 +7,15 @@ package exec_test import ( + "internal/testenv" + "os" + "os/exec" "os/user" + "path/filepath" + "reflect" "runtime" "strconv" + "strings" "syscall" "testing" "time" @@ -86,3 +92,146 @@ func TestWaitid(t *testing.T) { <-ch } + +// https://go.dev/issue/50599: if Env is not set explicitly, setting Dir should +// implicitly update PWD to the correct path, and Environ should list the +// updated value. +func TestImplicitPWD(t *testing.T) { + testenv.MustHaveExec(t) + _, pwdErr := exec.LookPath("pwd") + + t.Parallel() + + cwd, err := os.Getwd() + if err != nil { + t.Fatal(err) + } + + cases := []struct { + name string + dir string + want string + }{ + {"empty", "", cwd}, + {"dot", ".", cwd}, + {"dotdot", "..", filepath.Dir(cwd)}, + {"PWD", cwd, cwd}, + {"PWDdotdot", cwd + string(filepath.Separator) + "..", filepath.Dir(cwd)}, + } + + for _, tc := range cases { + tc := tc + t.Run(tc.name, func(t *testing.T) { + t.Parallel() + + // Note: we're using the actual "pwd" command here (instead of helperCommand) + // because the implementation of helperCommand requires a non-empty Env. + // (We could perhaps refactor helperCommand to use a flag or switch on the + // value of argv[0] instead, but that doesn't seem worth the trouble at + // the moment.) + cmd := exec.Command("pwd") + cmd.Dir = tc.dir + + var pwds []string + for _, kv := range cmd.Environ() { + if strings.HasPrefix(kv, "PWD=") { + pwds = append(pwds, strings.TrimPrefix(kv, "PWD=")) + } + } + + wantPWDs := []string{tc.want} + if tc.dir == "" { + if _, ok := os.LookupEnv("PWD"); !ok { + wantPWDs = nil + } + } + if !reflect.DeepEqual(pwds, wantPWDs) { + t.Errorf("PWD entries in cmd.Environ():\n\t%s\nwant:\n\t%s", strings.Join(pwds, "\n\t"), strings.Join(wantPWDs, "\n\t")) + } + + if pwdErr != nil { + t.Skipf("not running `pwd` because it was not found: %v", pwdErr) + } + cmd.Stderr = new(strings.Builder) + out, err := cmd.Output() + if err != nil { + t.Fatalf("%v:\n%s", err, cmd.Stderr) + } + got := strings.Trim(string(out), "\r\n") + t.Logf("in\n\t%s\n`pwd` reported\n\t%s", tc.dir, got) + if got != tc.want { + t.Errorf("want\n\t%s", tc.want) + } + }) + } +} + +// However, if cmd.Env is set explicitly, setting Dir should not override it. +// (This checks that the implementation for https://go.dev/issue/50599 doesn't +// break existing users who may have explicitly mismatched the PWD variable.) +func TestExplicitPWD(t *testing.T) { + testenv.MustHaveSymlink(t) + + cwd, err := os.Getwd() + if err != nil { + t.Fatal(err) + } + + link := filepath.Join(t.TempDir(), "link") + if err := os.Symlink(cwd, link); err != nil { + t.Fatal(err) + } + + // Now link is another equally-valid name for cwd. If we set Dir to one and + // PWD to the other, the subprocess should report the PWD version. + cases := []struct { + name string + dir string + pwd string + }{ + {name: "original PWD", pwd: cwd}, + {name: "link PWD", pwd: link}, + {name: "in link with original PWD", dir: link, pwd: cwd}, + {name: "in dir with link PWD", dir: cwd, pwd: link}, + // Ideally we would also like to test what happens if we set PWD to + // something totally bogus (or the empty string), but then we would have no + // idea what output the subprocess should actually produce: cwd itself may + // contain symlinks preserved from the PWD value in the test's environment. + } + for _, tc := range cases { + tc := tc + t.Run(tc.name, func(t *testing.T) { + t.Parallel() + + cmd := helperCommand(t, "pwd") + // This is intentionally opposite to the usual order of setting cmd.Dir + // and then calling cmd.Environ. Here, we *want* PWD not to match cmd.Dir, + // so we don't care whether cmd.Dir is reflected in cmd.Environ. + cmd.Env = append(cmd.Environ(), "PWD="+tc.pwd) + cmd.Dir = tc.dir + + var pwds []string + for _, kv := range cmd.Environ() { + if strings.HasPrefix(kv, "PWD=") { + pwds = append(pwds, strings.TrimPrefix(kv, "PWD=")) + } + } + + wantPWDs := []string{tc.pwd} + if !reflect.DeepEqual(pwds, wantPWDs) { + t.Errorf("PWD entries in cmd.Environ():\n\t%s\nwant:\n\t%s", strings.Join(pwds, "\n\t"), strings.Join(wantPWDs, "\n\t")) + } + + cmd.Stderr = new(strings.Builder) + out, err := cmd.Output() + if err != nil { + t.Fatalf("%v:\n%s", err, cmd.Stderr) + } + got := strings.Trim(string(out), "\r\n") + t.Logf("in\n\t%s\nwith PWD=%s\nsubprocess os.Getwd() reported\n\t%s", tc.dir, tc.pwd, got) + if got != tc.pwd { + t.Errorf("want\n\t%s", tc.pwd) + } + }) + } +} |