Merge pull request #792 from ajnavarro/fix/support-no-symref-capability
Resolve HEAD if symRefs capability is not supported
diff --git a/plumbing/protocol/packp/advrefs.go b/plumbing/protocol/packp/advrefs.go
index 7d644bc..684e76a 100644
--- a/plumbing/protocol/packp/advrefs.go
+++ b/plumbing/protocol/packp/advrefs.go
@@ -2,6 +2,7 @@
import (
"fmt"
+ "sort"
"strings"
"gopkg.in/src-d/go-git.v4/plumbing"
@@ -68,30 +69,119 @@
func (a *AdvRefs) AllReferences() (memory.ReferenceStorage, error) {
s := memory.ReferenceStorage{}
- if err := addRefs(s, a); err != nil {
+ if err := a.addRefs(s); err != nil {
return s, plumbing.NewUnexpectedError(err)
}
return s, nil
}
-func addRefs(s storer.ReferenceStorer, ar *AdvRefs) error {
- for name, hash := range ar.References {
+func (a *AdvRefs) addRefs(s storer.ReferenceStorer) error {
+ for name, hash := range a.References {
ref := plumbing.NewReferenceFromStrings(name, hash.String())
if err := s.SetReference(ref); err != nil {
return err
}
}
- return addSymbolicRefs(s, ar)
+ if a.supportSymrefs() {
+ return a.addSymbolicRefs(s)
+ }
+
+ return a.resolveHead(s)
}
-func addSymbolicRefs(s storer.ReferenceStorer, ar *AdvRefs) error {
- if !hasSymrefs(ar) {
+// If the server does not support symrefs capability,
+// we need to guess the reference where HEAD is pointing to.
+//
+// Git versions prior to 1.8.4.3 has an special procedure to get
+// the reference where is pointing to HEAD:
+// - Check if a reference called master exists. If exists and it
+// has the same hash as HEAD hash, we can say that HEAD is pointing to master
+// - If master does not exists or does not have the same hash as HEAD,
+// order references and check in that order if that reference has the same
+// hash than HEAD. If yes, set HEAD pointing to that branch hash
+// - If no reference is found, throw an error
+func (a *AdvRefs) resolveHead(s storer.ReferenceStorer) error {
+ if a.Head == nil {
return nil
}
- for _, symref := range ar.Capabilities.Get(capability.SymRef) {
+ ref, err := s.Reference(plumbing.ReferenceName(plumbing.Master))
+
+ // check first if HEAD is pointing to master
+ if err == nil {
+ ok, err := a.createHeadIfCorrectReference(ref, s)
+ if err != nil {
+ return err
+ }
+
+ if ok {
+ return nil
+ }
+ }
+
+ if err != nil && err != plumbing.ErrReferenceNotFound {
+ return err
+ }
+
+ // From here we are trying to guess the branch that HEAD is pointing
+ refIter, err := s.IterReferences()
+ if err != nil {
+ return err
+ }
+
+ var refNames []string
+ err = refIter.ForEach(func(r *plumbing.Reference) error {
+ refNames = append(refNames, string(r.Name()))
+ return nil
+ })
+ if err != nil {
+ return err
+ }
+
+ sort.Strings(refNames)
+
+ var headSet bool
+ for _, refName := range refNames {
+ ref, err := s.Reference(plumbing.ReferenceName(refName))
+ if err != nil {
+ return err
+ }
+ ok, err := a.createHeadIfCorrectReference(ref, s)
+ if err != nil {
+ return err
+ }
+ if ok {
+ headSet = true
+ break
+ }
+ }
+
+ if !headSet {
+ return plumbing.ErrReferenceNotFound
+ }
+
+ return nil
+}
+
+func (a *AdvRefs) createHeadIfCorrectReference(
+ reference *plumbing.Reference,
+ s storer.ReferenceStorer) (bool, error) {
+ if reference.Hash() == *a.Head {
+ headRef := plumbing.NewSymbolicReference(plumbing.HEAD, reference.Name())
+ if err := s.SetReference(headRef); err != nil {
+ return false, err
+ }
+
+ return true, nil
+ }
+
+ return false, nil
+}
+
+func (a *AdvRefs) addSymbolicRefs(s storer.ReferenceStorer) error {
+ for _, symref := range a.Capabilities.Get(capability.SymRef) {
chunks := strings.Split(symref, ":")
if len(chunks) != 2 {
err := fmt.Errorf("bad number of `:` in symref value (%q)", symref)
@@ -108,6 +198,6 @@
return nil
}
-func hasSymrefs(ar *AdvRefs) bool {
- return ar.Capabilities.Supports(capability.SymRef)
+func (a *AdvRefs) supportSymrefs() bool {
+ return a.Capabilities.Supports(capability.SymRef)
}
diff --git a/plumbing/protocol/packp/advrefs_test.go b/plumbing/protocol/packp/advrefs_test.go
index 0180fd3..bb8d032 100644
--- a/plumbing/protocol/packp/advrefs_test.go
+++ b/plumbing/protocol/packp/advrefs_test.go
@@ -79,6 +79,79 @@
c.Assert(err, NotNil)
}
+func (s *AdvRefSuite) TestNoSymRefCapabilityHeadToMaster(c *C) {
+ a := NewAdvRefs()
+ headHash := plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c")
+ a.Head = &headHash
+ ref := plumbing.NewHashReference(plumbing.Master, plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c"))
+
+ err := a.AddReference(ref)
+ c.Assert(err, IsNil)
+
+ storage, err := a.AllReferences()
+ c.Assert(err, IsNil)
+
+ head, err := storage.Reference(plumbing.HEAD)
+ c.Assert(err, IsNil)
+ c.Assert(head.Target(), Equals, ref.Name())
+}
+
+func (s *AdvRefSuite) TestNoSymRefCapabilityHeadToOtherThanMaster(c *C) {
+ a := NewAdvRefs()
+ headHash := plumbing.NewHash("0000000000000000000000000000000000000000")
+ a.Head = &headHash
+ ref1 := plumbing.NewHashReference(plumbing.Master, plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c"))
+ ref2 := plumbing.NewHashReference("other/ref", plumbing.NewHash("0000000000000000000000000000000000000000"))
+
+ err := a.AddReference(ref1)
+ c.Assert(err, IsNil)
+ err = a.AddReference(ref2)
+ c.Assert(err, IsNil)
+
+ storage, err := a.AllReferences()
+ c.Assert(err, IsNil)
+
+ head, err := storage.Reference(plumbing.HEAD)
+ c.Assert(err, IsNil)
+ c.Assert(head.Hash(), Equals, ref2.Hash())
+}
+
+func (s *AdvRefSuite) TestNoSymRefCapabilityHeadToNoRef(c *C) {
+ a := NewAdvRefs()
+ headHash := plumbing.NewHash("0000000000000000000000000000000000000000")
+ a.Head = &headHash
+ ref := plumbing.NewHashReference(plumbing.Master, plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c"))
+
+ err := a.AddReference(ref)
+ c.Assert(err, IsNil)
+
+ _, err = a.AllReferences()
+ c.Assert(err, NotNil)
+}
+
+func (s *AdvRefSuite) TestNoSymRefCapabilityHeadToNoMasterAlphabeticallyOrdered(c *C) {
+ a := NewAdvRefs()
+ headHash := plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c")
+ a.Head = &headHash
+ ref1 := plumbing.NewHashReference(plumbing.Master, plumbing.NewHash("0000000000000000000000000000000000000000"))
+ ref2 := plumbing.NewHashReference("aaaaaaaaaaaaaaa", plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c"))
+ ref3 := plumbing.NewHashReference("bbbbbbbbbbbbbbb", plumbing.NewHash("5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c"))
+
+ err := a.AddReference(ref1)
+ c.Assert(err, IsNil)
+ err = a.AddReference(ref3)
+ c.Assert(err, IsNil)
+ err = a.AddReference(ref2)
+ c.Assert(err, IsNil)
+
+ storage, err := a.AllReferences()
+ c.Assert(err, IsNil)
+
+ head, err := storage.Reference(plumbing.HEAD)
+ c.Assert(err, IsNil)
+ c.Assert(head.Target(), Equals, ref2.Name())
+}
+
type AdvRefsDecodeEncodeSuite struct{}
var _ = Suite(&AdvRefsDecodeEncodeSuite{})
