Merge branch 'rs/sha1-file-plug-fallback-base-leak'

A leak in a codepath to read from a packed object in (rare) cases
has been plugged.

* rs/sha1-file-plug-fallback-base-leak:
  sha1_file: release fallback base's memory in unpack_entry()
diff --git a/sha1_file.c b/sha1_file.c
index 6628f06..2ee3c61 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2606,6 +2606,7 @@
 	while (delta_stack_nr) {
 		void *delta_data;
 		void *base = data;
+		void *external_base = NULL;
 		unsigned long delta_size, base_size = size;
 		int i;
 
@@ -2632,6 +2633,7 @@
 				      p->pack_name);
 				mark_bad_packed_object(p, base_sha1);
 				base = read_object(base_sha1, &type, &base_size);
+				external_base = base;
 			}
 		}
 
@@ -2650,6 +2652,7 @@
 			      "at offset %"PRIuMAX" from %s",
 			      (uintmax_t)curpos, p->pack_name);
 			data = NULL;
+			free(external_base);
 			continue;
 		}
 
@@ -2669,6 +2672,7 @@
 			error("failed to apply delta");
 
 		free(delta_data);
+		free(external_base);
 	}
 
 	*final_type = type;