indexer: introduce `git_packfile_close`

Encapsulation!

src/indexer.c

@@ -1091,17 +1091,10 @@ void git_indexer_free(git_indexer *idx)
 
 	git_vector_free_deep(&idx->deltas);
 
-	/* Try to delete the temporary file in case it was not committed. */
-	git_mwindow_free_all(&idx->pack->mwf);
-
-	/* We need to close the descriptor here so Windows doesn't choke on unlink */
-	if (idx->pack->mwf.fd != -1)
-		p_close(idx->pack->mwf.fd);
-
-	if (!idx->pack_committed)
-		p_unlink(idx->pack->pack_name);
-
 	if (!git_mutex_lock(&git__mwindow_mutex)) {
+		if (!idx->pack_committed)
+			git_packfile_close(idx->pack, true);
+
 		git_packfile_free(idx->pack);
 		git_mutex_unlock(&git__mwindow_mutex);
 	}

src/pack.c

@@ -991,6 +991,18 @@ git_off_t get_delta_base(
  *
  ***********************************************************/
 
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile)
+{
+	if (p->mwf.fd >= 0) {
+		git_mwindow_free_all_locked(&p->mwf);
+		p_close(p->mwf.fd);
+		p->mwf.fd = -1;
+	}
+
+	if (unlink_packfile)
+		p_unlink(p->pack_name);
+}
+
 void git_packfile_free(struct git_pack_file *p)
 {
 	if (!p)
@@ -998,10 +1010,7 @@ void git_packfile_free(struct git_pack_file *p)
 
 	cache_free(&p->bases);
 
-	if (p->mwf.fd >= 0) {
-		git_mwindow_free_all_locked(&p->mwf);
-		p_close(p->mwf.fd);
-	}
+	git_packfile_close(p, false);
 
 	pack_index_free(p);
 

src/pack.h

@@ -149,6 +149,7 @@ git_off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
 		git_off_t *curpos, git_otype type,
 		git_off_t delta_obj_offset);
 
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile);
 void git_packfile_free(struct git_pack_file *p);
 int git_packfile_alloc(struct git_pack_file **pack_out, const char *path);