Merge pull request #2829 from AZero13/leak-shar

archive_write_shar_header: free shar->last_dir before replacement

(cherry picked from commit 8c2241a7e4)

libarchive/archive_write_set_format_shar.c

@@ -242,6 +242,7 @@ archive_write_shar_header(struct archive_write *a, struct archive_entry *entry)
 				shar_quote(&shar->work, p, 1);
 				archive_strcat(&shar->work,
 				    " > /dev/null 2>&1\n");
+				free(shar->last_dir);
 				shar->last_dir = p;
 			}
 		} else {