diff --git a/src/cmd/go/internal/modfetch/codehost/git.go b/src/cmd/go/internal/modfetch/codehost/git.go index 87940a8f02c..bcf86098262 100644 --- a/src/cmd/go/internal/modfetch/codehost/git.go +++ b/src/cmd/go/internal/modfetch/codehost/git.go @@ -694,6 +694,10 @@ func (r *gitRepo) ReadZip(rev, subdir string, maxSize int64) (zip io.ReadCloser, return nil, "", err } + if err := ensureGitAttributes(r.dir); err != nil { + return nil, "", err + } + // Incredibly, git produces different archives depending on whether // it is running on a Windows system or not, in an attempt to normalize // text file line endings. Setting -c core.autocrlf=input means only @@ -709,3 +713,43 @@ func (r *gitRepo) ReadZip(rev, subdir string, maxSize int64) (zip io.ReadCloser, return ioutil.NopCloser(bytes.NewReader(archive)), "", nil } + +// ensureGitAttributes makes sure export-subst and export-ignore features are +// disabled for this repo. This is intended to be run prior to running git +// archive so that zip files are generated that produce consistent ziphashes +// for a given revision, independent of variables such as git version and the +// size of the repo. +// +// See: https://github.com/golang/go/issues/27153 +func ensureGitAttributes(repoDir string) (err error) { + const attr = "\n* -export-subst -export-ignore\n" + + d := repoDir + "/info" + p := d + "/attributes" + + if err := os.MkdirAll(d, 0755); err != nil { + return err + } + + f, err := os.OpenFile(p, os.O_CREATE|os.O_APPEND|os.O_RDWR, 0666) + if err != nil { + return err + } + defer func() { + closeErr := f.Close() + if closeErr != nil { + err = closeErr + } + }() + + b, err := ioutil.ReadAll(f) + if err != nil { + return err + } + if !bytes.HasSuffix(b, []byte(attr)) { + _, err := f.WriteString(attr) + return err + } + + return nil +} diff --git a/src/cmd/go/testdata/script/mod_git_export_subst.txt b/src/cmd/go/testdata/script/mod_git_export_subst.txt new file mode 100644 index 00000000000..2b8e2bc7bc0 --- /dev/null +++ b/src/cmd/go/testdata/script/mod_git_export_subst.txt @@ -0,0 +1,21 @@ +env GO111MODULE=on +env GOPROXY= + +# Testing that git export-subst is disabled +[!net] skip +[!exec:git] skip +go build + +-- x.go -- +package x + +import _ "github.com/jasonkeene/export-subst" + +-- go.mod -- +module x + +require github.com/jasonkeene/export-subst v0.0.0-20180927204031-5845945ec626 + +-- go.sum -- +github.com/jasonkeene/export-subst v0.0.0-20180927204031-5845945ec626 h1:AUkXi/xFnm7lH2pgtvVkGb7buRn1ywFHw+xDpZ29Rz0= +github.com/jasonkeene/export-subst v0.0.0-20180927204031-5845945ec626/go.mod h1:DwJXqVtrgrQkv3Giuf2Jh4YyubVe7y41S1eOIaysTJw=