commit 87c1ed2b2f3cd42280054f037b5a32c8fe6b7013
from: Stefan Sperling <stsp@stsp.name>
date: Tue Jan 07 21:50:38 2020 UTC

don't bother swapping the first pack index cache pointer, and improve comment

commit - f73df793baa4ec89bcbfb0fddb9765c4187defc8
commit + 87c1ed2b2f3cd42280054f037b5a32c8fe6b7013
blob - 358389209a5812144cf90fd8c59a48aee2b1c150
blob + d1f67080cf2eb7c75f2329144cafe40603ae771f
--- lib/repository.c
+++ lib/repository.c
@@ -850,12 +850,17 @@ got_repo_search_packidx(struct got_packidx **packidx, 
 			break;
 		*idx = got_packidx_get_object_idx(repo->packidx_cache[i], id);
 		if (*idx != -1) {
-			struct got_packidx *p;
-			/* Move matched cache entry to the front. */
-			p = repo->packidx_cache[0];
 			*packidx = repo->packidx_cache[i];
-			repo->packidx_cache[0] = *packidx;
-			repo->packidx_cache[i] = p;
+			/*
+			 * Move this cache entry to the front. Repeatedly
+			 * searching a wrong pack index can be expensive.
+			 */
+			if (i > 0) {
+				struct got_packidx *p;
+				p = repo->packidx_cache[0];
+				repo->packidx_cache[0] = *packidx;
+				repo->packidx_cache[i] = p;
+			}
 			return NULL;
 		}
 	}