From: Bryan C. Mills <bcmills@google.com>
Date: Thu, 26 Mar 2020 02:24:44 +0000 (-0400)
Subject: cmd/go: do not append to the global cfg.OrigEnv slice
X-Git-Tag: go1.15beta1~746
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=bfb1342a40216cba0ff5ae3a1b102823b7603068;p=gostls13.git

cmd/go: do not append to the global cfg.OrigEnv slice

Appending to a global slice is only safe if its length is already
equal to its capacity. That property is not guaranteed for slices in
general, and empirically does not hold for this one.

This is a minimal fix to make it easier to backport.
A more robust cleanup of the base.EnvForDir function will be sent in a
subsequent CL.

Fixes #38077
Updates #37940

Change-Id: I731d5bbd0e516642c2cf43e713eeea15402604e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/225577
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
---

diff --git a/src/cmd/go/internal/generate/generate.go b/src/cmd/go/internal/generate/generate.go
index 198ca1c1b9..315db69de8 100644
--- a/src/cmd/go/internal/generate/generate.go
+++ b/src/cmd/go/internal/generate/generate.go
@@ -22,6 +22,7 @@ import (
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
+	"cmd/go/internal/str"
 	"cmd/go/internal/work"
 )
 
@@ -438,7 +439,7 @@ func (g *Generator) exec(words []string) {
 	cmd.Stderr = os.Stderr
 	// Run the command in the package directory.
 	cmd.Dir = g.dir
-	cmd.Env = append(cfg.OrigEnv, g.env...)
+	cmd.Env = str.StringList(cfg.OrigEnv, g.env)
 	err := cmd.Run()
 	if err != nil {
 		g.errorf("running %q: %s", words[0], err)
diff --git a/src/cmd/go/internal/test/test.go b/src/cmd/go/internal/test/test.go
index dbb899219d..ec7bde16fe 100644
--- a/src/cmd/go/internal/test/test.go
+++ b/src/cmd/go/internal/test/test.go
@@ -1157,7 +1157,7 @@ func (c *runCache) builderRunTest(b *work.Builder, a *work.Action) error {
 
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = a.Package.Dir
-	cmd.Env = base.EnvForDir(cmd.Dir, cfg.OrigEnv)
+	cmd.Env = base.EnvForDir(cmd.Dir, cfg.OrigEnv[:len(cfg.OrigEnv):len(cfg.OrigEnv)])
 	cmd.Stdout = stdout
 	cmd.Stderr = stdout