thodg/libgit2

diff --git a/src/tree.c b/src/tree.c
index 7b47af3..150f90c 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -26,7 +26,9 @@ static bool valid_filemode(const int filemode)
 
 static int valid_entry_name(const char *filename)
 {
-	return *filename != '\0' && strchr(filename, '/') == NULL;
+	return *filename != '\0' && strchr(filename, '/') == NULL &&
+		strcmp(filename, "..") != 0 && strcmp(filename, ".") != 0 &&
+		strcmp(filename, ".git") != 0;
 }
 
 static int entry_sort_cmp(const void *a, const void *b)
diff --git a/tests-clar/object/tree/write.c b/tests-clar/object/tree/write.c
index 657bed2..cc5438b 100644
--- a/tests-clar/object/tree/write.c
+++ b/tests-clar/object/tree/write.c
@@ -39,6 +39,12 @@ void test_object_tree_write__from_memory(void)
 		&bid, GIT_FILEMODE_BLOB));
 	cl_git_fail(git_treebuilder_insert(NULL, builder, "/",
 		&bid, GIT_FILEMODE_BLOB));
+	cl_git_fail(git_treebuilder_insert(NULL, builder, ".git",
+		&bid, GIT_FILEMODE_BLOB));
+	cl_git_fail(git_treebuilder_insert(NULL, builder, "..",
+		&bid, GIT_FILEMODE_BLOB));
+	cl_git_fail(git_treebuilder_insert(NULL, builder, ".",
+		&bid, GIT_FILEMODE_BLOB));
 	cl_git_fail(git_treebuilder_insert(NULL, builder, "folder/new.txt",
 		&bid, GIT_FILEMODE_BLOB));