cmd/go: env -w validates GOTMPDIR value

This change makes go env -w check if GOTMPDIR is an absolute path.

If GOTMPDIR is not an absolute and not existing path there will be an
error at every `work.Builder.Init()`. If `go env` has `-u/-w` as
argument `work.Builder.Init()` is not called.

`go env -w GOTMPDIR=` work in the same way as `go env -u GOTMPDIR`.

Fixes #40932

Change-Id: I6b0662302eeace7f20460b6d26c6e59af1111da2
Reviewed-on: https://go-review.googlesource.com/c/go/+/250198
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Jay Conrod <jayconrod@google.com>

diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index e1f2400f60b1f7a6cb70bceb71fec6eabbcfdc17..59d0ded658e77a43fbb99193552b5e0e53f45f43 100644 (file)
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -203,10 +203,19 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
        }
 
        // Do we need to call ExtraEnvVarsCostly, which is a bit expensive?
-       // Only if we're listing all environment variables ("go env")
-       // or the variables being requested are in the extra list.
-       needCostly := true
-       if len(args) > 0 {
+       needCostly := false
+       if *envU || *envW {
+               // We're overwriting or removing default settings,
+               // so it doesn't really matter what the existing settings are.
+               //
+               // Moreover, we haven't validated the new settings yet, so it is
+               // important that we NOT perform any actions based on them,
+               // such as initializing the builder to compute other variables.
+       } else if len(args) == 0 {
+               // We're listing all environment variables ("go env"),
+               // including the expensive ones.
+               needCostly = true
+       } else {
                needCostly = false
                for _, arg := range args {
                        switch argKey(arg) {
@@ -269,6 +278,13 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
                        }
                }
 
+               gotmp, okGOTMP := add["GOTMPDIR"]
+               if okGOTMP {
+                       if !filepath.IsAbs(gotmp) && gotmp != "" {
+                               base.Fatalf("go env -w: GOTMPDIR must be an absolute path")
+                       }
+               }
+
                updateEnvFile(add, nil)
                return
        }

diff --git a/src/cmd/go/testdata/script/env_write.txt b/src/cmd/go/testdata/script/env_write.txt
index 2366c3f580f4da7423af0f39555794caf96d9aa3..bdb9bc4077c07d9b97831e83d66c0253b9fe7d35 100644 (file)
--- a/src/cmd/go/testdata/script/env_write.txt
+++ b/src/cmd/go/testdata/script/env_write.txt
@@ -24,6 +24,12 @@ stdout GOARCH=
 stdout GOOS=
 stdout GOROOT=
 
+# checking errors
+! go env -w
+stderr 'go env -w: no KEY=VALUE arguments given'
+! go env -u
+stderr 'go env -u: no arguments given'
+
 # go env -w changes default setting
 env root=
 [windows] env root=c:
@@ -97,6 +103,26 @@ stderr 'GOPATH entry cannot start with shell metacharacter'
 ! go env -w GOPATH=./go
 stderr 'GOPATH entry is relative; must be absolute path'
 
+# go env -w rejects invalid GOTMPDIR values
+! go env -w GOTMPDIR=x
+stderr 'go env -w: GOTMPDIR must be an absolute path'
+
+# go env -w should accept absolute GOTMPDIR value
+# and should not create it
+[windows] go env -w GOTMPDIR=$WORK\x\y\z
+[!windows] go env -w GOTMPDIR=$WORK/x/y/z
+! exists $WORK/x/y/z
+# we should be able to clear an env
+go env -u GOTMPDIR
+go env GOTMPDIR
+stdout ^$
+
+[windows] go env -w GOTMPDIR=$WORK\x\y\z
+[!windows] go env -w GOTMPDIR=$WORK/x/y/z
+go env -w GOTMPDIR=
+go env GOTMPDIR
+stdout ^$
+
 # go env -w/-u checks validity of GOOS/ARCH combinations
 env GOOS=
 env GOARCH=