Fix some bugs found during gypogit testing

cshared/file_cshared.go

@@ -2,8 +2,11 @@ package main
 
 import (
 	"C"
+	"io"
+	"io/ioutil"
 
 	"gopkg.in/src-d/go-git.v3"
+	"gopkg.in/src-d/go-git.v3/core"
 )
 
 //export c_File_get_Name
@@ -26,6 +29,67 @@ func c_File_get_Mode(f uint64) uint32 {
 	return uint32(file.Mode)
 }
 
+//export c_File_get_Hash
+func c_File_get_Hash(b uint64) *C.char {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return nil
+	}
+	file := obj.(*git.File)
+	return CBytes(file.Hash[:])
+}
+
+//export c_File_Size
+func c_File_Size(b uint64) int64 {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return -1
+	}
+	file := obj.(*git.File)
+	return file.Size
+}
+
+//export c_File_Decode
+func c_File_Decode(o uint64) uint64 {
+	obj, ok := GetObject(Handle(o))
+	if !ok {
+		return IH
+	}
+	cobj := obj.(*core.Object)
+	file := git.File{}
+	file.Decode(*cobj)
+	return uint64(RegisterObject(&file))
+}
+
+//export c_File_Read
+func c_File_Read(b uint64) (int, *C.char) {
+	obj, ok := GetObject(Handle(b))
+	if !ok {
+		return ErrorCodeNotFound, C.CString(MessageNotFound)
+	}
+	file := obj.(*git.File)
+	reader, err := file.Reader()
+	if err != nil {
+		return ErrorCodeInternal, C.CString(err.Error())
+	}
+  data, err := ioutil.ReadAll(reader)
+	reader.Close()
+	if err != nil {
+		return ErrorCodeInternal, C.CString(err.Error())
+	}
+	return len(data), CBytes(data)
+}
+
+//export c_File_Type
+func c_File_Type(c uint64) int8 {
+	obj, ok := GetObject(Handle(c))
+	if !ok {
+		return -1
+	}
+	file := obj.(*git.File)
+	return int8(file.Type())
+}
+
 //export c_NewFileIter
 func c_NewFileIter(r uint64, t uint64) uint64 {
 	obj, ok := GetObject(Handle(r))
@@ -51,6 +115,9 @@ func c_FileIter_Next(i uint64) (uint64, int, *C.char) {
 	iter := obj.(*git.FileIter)
 	file, err := iter.Next()
 	if err != nil {
+		if err == io.EOF {
+			return IH, ErrorCodeSuccess, nil
+		}
 		return IH, ErrorCodeInternal, C.CString(err.Error())
 	}
 	return uint64(RegisterObject(file)), ErrorCodeSuccess, nil

cshared/objects_cshared.go

@@ -95,5 +95,15 @@ func c_Blob_Read(b uint64) (int, *C.char) {
 	if err != nil {
 		return ErrorCodeInternal, C.CString(err.Error())
 	}
-	return len(data), C.CString(string(data))
+	return len(data), CBytes(data)
+}
+
+//export c_Blob_Type
+func c_Blob_Type(c uint64) int8 {
+	obj, ok := GetObject(Handle(c))
+	if !ok {
+		return -1
+	}
+	blob := obj.(*git.Blob)
+	return int8(blob.Type())
 }

cshared/tag_cshared.go

@@ -3,6 +3,7 @@ package main
 
 import (
 	"C"
+	"io"
 
 	"gopkg.in/src-d/go-git.v3"
 	"gopkg.in/src-d/go-git.v3/core"
@@ -177,6 +178,9 @@ func c_TagIter_Next(i uint64) (uint64, int, *C.char) {
 	tagiter := obj.(*git.TagIter)
 	tag, err := tagiter.Next()
 	if err != nil {
+		if err == io.EOF {
+			return IH, ErrorCodeSuccess, nil
+		}
 		return IH, ErrorCodeInternal, C.CString(err.Error())
 	}
 	return uint64(RegisterObject(tag)), ErrorCodeSuccess, nil

cshared/tree_cshared.go

@@ -39,6 +39,7 @@ func c_Tree_get_Hash(t uint64) *C.char {
 	return CBytes(tree.Hash[:])
 }
 
+//export c_Tree_File
 func c_Tree_File(t uint64, path string) (uint64, int, *C.char) {
 	obj, ok := GetObject(Handle(t))
 	if !ok {