Add decode bad commit test

Author: fcharlie

commit_test.go

@@ -455,3 +455,20 @@ func TestCommitEqualReturnsTrueWhenBothCommitsAreNil(t *testing.T) {
 
 	assert.True(t, c1.Equal(c2))
 }
+
+func TestBadCommit(t *testing.T) {
+	cc := `tree 2aedfd35087c75d17bdbaf4dd56069d44fc75b71
+parent 75158117eb8efe60453f8c077527ac3530c81e38
+author Credit Card Account <Credit Card Account> 1722305889 +0800
+committer \346\244\260\346\235\215
+ <Credit Card Account> 1722305889 +0800
+
+Credit Card Account`
+	var c Commit
+	_, err := c.Decode(sha1.New(), strings.NewReader(cc), int64(len(cc)))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "decode error: '%v'\n", err)
+		return
+	}
+	fmt.Fprintf(os.Stderr, "%v\n", c)
+}