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author | Jason Keene <jasonkeene@gmail.com> | 2018-09-12 20:35:58 -0600 |
---|---|---|
committer | Bryan C. Mills <bcmills@google.com> | 2018-10-04 22:08:53 +0000 |
commit | 1bca6cecc627cd708c6c5440eb14f84a99d5324b (patch) | |
tree | 0265c3262ff28f42d575260086e26d7ac9cbcf8d /src/cmd/go/internal/modfetch/codehost/git.go | |
parent | fa179eb89d881565238a21a8a740de6ca3cf9bc2 (diff) | |
download | go-1bca6cecc627cd708c6c5440eb14f84a99d5324b.tar.gz go-1bca6cecc627cd708c6c5440eb14f84a99d5324b.zip |
cmd/go: ensure git attributes are set
This change disables the export-subst and export-ignore attributes when
creating zip files for modules. This is done to prevent the ziphash for
a given repo/revision from differing based on variables such as git
version or size of repo. The full rational for this change is detailed
here:
https://github.com/golang/go/issues/27153#issuecomment-420763082
Fixes #27153
Change-Id: Ib33f525d91d2581fa0b5d26e70d29620c7e685e9
Reviewed-on: https://go-review.googlesource.com/c/135175
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Diffstat (limited to 'src/cmd/go/internal/modfetch/codehost/git.go')
-rw-r--r-- | src/cmd/go/internal/modfetch/codehost/git.go | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/cmd/go/internal/modfetch/codehost/git.go b/src/cmd/go/internal/modfetch/codehost/git.go index 87940a8f02..bcf8609826 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 +} |