1 files changed, 29 insertions, 21 deletions

diff --git a/git.go b/git.go
index 07892e4..db9522b 100644
--- a/git.go
+++ b/git.go
@@ -1,7 +1,7 @@
 package git
 
 /*
-#cgo pkg-config: --static libgit2
+#cgo pkg-config: libgit2
 #include <git2.h>
 #include <git2/errors.h>
 */
@@ -10,8 +10,8 @@ import (
 	"bytes"
 	"errors"
 	"runtime"
-	"unsafe"
 	"strings"
+	"unsafe"
 )
 
 const (
@@ -61,8 +61,8 @@ func NewOidFromString(s string) (*Oid, error) {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
-	if C.git_oid_fromstr(o.toC(), cs) < 0 {
-		return nil, LastError()
+	if ret := C.git_oid_fromstr(o.toC(), cs); ret < 0 {
+		return nil, MakeGitError(ret)
 	}
 
 	return o, nil
@@ -93,7 +93,7 @@ func (oid *Oid) Equal(oid2 *Oid) bool {
 }
 
 func (oid *Oid) IsZero() bool {
-	for _, a := range(oid.bytes) {
+	for _, a := range oid.bytes {
 		if a != '0' {
 			return false
 		}
@@ -123,38 +123,47 @@ func ShortenOids(ids []*Oid, minlen int) (int, error) {
 		buf[40] = 0
 		ret = C.git_oid_shorten_add(shorten, (*C.char)(unsafe.Pointer(&buf[0])))
 		if ret < 0 {
-			return int(ret), LastError()
+			return int(ret), MakeGitError(ret)
 		}
 	}
 	return int(ret), nil
 }
 
 type GitError struct {
-	Message string
-	Code int
+	Message   string
+	Class     int
+	ErrorCode int
 }
 
-func (e GitError) Error() string{
+func (e GitError) Error() string {
 	return e.Message
 }
 
-func LastError() error {
+func IsNotExist(err error) bool {
+	return err.(*GitError).ErrorCode == C.GIT_ENOTFOUND
+}
+
+func IsExist(err error) bool {
+	return err.(*GitError).ErrorCode == C.GIT_EEXISTS
+}
+
+func MakeGitError(errorCode C.int) error {
 	err := C.giterr_last()
 	if err == nil {
-		return &GitError{"No message", 0}
+		return &GitError{"No message", C.GITERR_INVALID, C.GIT_ERROR}
 	}
-	return &GitError{C.GoString(err.message), int(err.klass)}
+	return &GitError{C.GoString(err.message), int(err.klass), int(errorCode)}
 }
 
 func cbool(b bool) C.int {
-	if (b) {
+	if b {
 		return C.int(1)
 	}
 	return C.int(0)
 }
 
 func ucbool(b bool) C.uint {
-	if (b) {
+	if b {
 		return C.uint(1)
 	}
 	return C.uint(0)
@@ -167,17 +176,16 @@ func Discover(start string, across_fs bool, ceiling_dirs []string) (string, erro
 	cstart := C.CString(start)
 	defer C.free(unsafe.Pointer(cstart))
 
-	retpath := (*C.char)(C.malloc(C.GIT_PATH_MAX))
-	defer C.free(unsafe.Pointer(retpath))
+	var buf C.git_buf
+	defer C.git_buf_free(&buf)
 
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
-	r := C.git_repository_discover(retpath, C.GIT_PATH_MAX, cstart, cbool(across_fs), ceildirs)
-
-	if r == 0 {
-		return C.GoString(retpath), nil
+	ret := C.git_repository_discover(&buf, cstart, cbool(across_fs), ceildirs)
+	if ret < 0 {
+		return "", MakeGitError(ret)
 	}
 
-	return "", LastError()
+	return C.GoString(buf.ptr), nil
 }