commit 9394843506b5859aab24498152a3adcf21a76b12
from: Stefan Sperling <stsp@stsp.name>
via: Thomas Adam <thomas@xteddy.org>
date: Mon Jun 13 17:55:22 2022 UTC

properly swap cached struct pack array elements in got_repo_cache_pack()

Avoids clobbering open files for delta base/accumulation, leaking file
descriptors, and triggering errors from close(2) during got_repo_close()
as we try to close the same file descriptor more than once.

commit - a0f32f336ed3ba83f8d1afc8165502d06c472866
commit + 9394843506b5859aab24498152a3adcf21a76b12
blob - 0e3f94fa40530b3a7da3a2953d72393dce749ff8
blob + 873467bcc9388aac56c737347130ba38ef7f9564
--- lib/repository.c
+++ lib/repository.c
@@ -1341,6 +1341,7 @@ got_repo_cache_pack(struct got_pack **packp, struct go
 	}
 
 	if (i == repo->pack_cache_size) {
+		struct got_pack tmp;
 		err = got_pack_close(&repo->packs[i - 1]);
 		if (err)
 			return err;
@@ -1348,8 +1349,10 @@ got_repo_cache_pack(struct got_pack **packp, struct go
 			return got_error_from_errno("ftruncate");
 		if (ftruncate(repo->packs[i - 1].accumfd, 0L) == -1)
 			return got_error_from_errno("ftruncate");
-		memmove(&repo->packs[1], &repo->packs[0],
-		    sizeof(repo->packs) - sizeof(repo->packs[0]));
+		memcpy(&tmp, &repo->packs[i - 1], sizeof(tmp)); 
+		memcpy(&repo->packs[i - 1], &repo->packs[0],
+		    sizeof(repo->packs[i - 1]));
+		memcpy(&repo->packs[0], &tmp, sizeof(repo->packs[0]));
 		i = 0;
 	}