Fix for short symlinks (#115)

Signed-off-by: Tris Forster <tris.git@shoddynet.org>

tests/repos/repo1_bare/objects/37/991dec2c8e592043f47155ce4808d4580f9123

@@ -0,0 +1 @@
+x
<01>ŽKN1YçÞ#<23>ç3	!Øp.<2E>ØÎL‹™J›·§á,kñê<15>û}5 PlªB÷5sKÔH|>ŸdíKÌKl	kì% û¬S7ƒÜ›ä¢e¡Ó¢™c¥Î‰±çÆH‡§Señ®~ÙuLxŸëocì Óeµ—ý:D¾7µÓ˜—gð‰¢_Bñ=":þËüÝüSà^ETàø™·uûp?ƒ6M^

tests/repos/repo1_bare/refs/heads/master

@@ -1 +1 @@
-6fbd69e9823458e6c4a2fc5c0f6bc022b2f2acd1
+37991dec2c8e592043f47155ce4808d4580f9123

tree_entry.go

@@ -112,7 +112,7 @@ func (te *TreeEntry) FollowLink() (*TreeEntry, error) {
 	t := te.ptree
 
 	// traverse up directories
-	for ; t != nil && lnk[:3] == "../"; lnk = lnk[3:] {
+	for ; t != nil && strings.HasPrefix(lnk, "../"); lnk = lnk[3:] {
 		t = t.ptree
 	}
 

tree_entry_test.go

@@ -55,7 +55,7 @@ func TestFollowLink(t *testing.T) {
 	r, err := OpenRepository("tests/repos/repo1_bare")
 	assert.NoError(t, err)
 
-	commit, err := r.GetCommit("6fbd69e9823458e6c4a2fc5c0f6bc022b2f2acd1")
+	commit, err := r.GetCommit("37991dec2c8e592043f47155ce4808d4580f9123")
 	assert.NoError(t, err)
 
 	// get the symlink
@@ -89,4 +89,10 @@ func TestFollowLink(t *testing.T) {
 	assert.True(t, target.IsLink())
 	_, err = target.FollowLink()
 	assert.Equal(t, err.Error(), "outside_repo: points outside of repo")
+
+	// testing fix for short link bug
+	target, err = commit.Tree.GetTreeEntryByPath("foo/link_short")
+	assert.NoError(t, err)
+	_, err = target.FollowLink()
+	assert.Equal(t, err.Error(), "link_short: broken link")
 }