Create the repository within the test

This change moves the humongous static repository with 1025 commits into
the test file, now with a more modest 16 commits.

tests/pack/filelimit.c

 #include "clar_libgit2.h"
 #include "mwindow.h"
 #include "global.h"
+
 #include <git2.h>
+#include "git2/sys/commit.h"
+#include "git2/sys/mempack.h"
+
+static size_t _expected_open_mwindow_files = 0;
+static size_t _original_mwindow_file_limit = 0;
 
 extern git_mwindow_ctl git_mwindow__mem_ctl;
-size_t mwindow_file_limit = 0;
-size_t original_mwindow_file_limit = 0;
 
 void test_pack_filelimit__initialize_tiny(void)
 {
-	mwindow_file_limit = 1;
-	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, &original_mwindow_file_limit));
-	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, mwindow_file_limit));
+	_expected_open_mwindow_files = 1;
+	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, &_original_mwindow_file_limit));
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, _expected_open_mwindow_files));
 }
 
 void test_pack_filelimit__initialize_medium(void)
 {
-	mwindow_file_limit = 100;
-	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, &original_mwindow_file_limit));
-	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, mwindow_file_limit));
+	_expected_open_mwindow_files = 10;
+	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, &_original_mwindow_file_limit));
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, _expected_open_mwindow_files));
+}
+
+void test_pack_filelimit__initialize_unlimited(void)
+{
+	_expected_open_mwindow_files = 15;
+	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, &_original_mwindow_file_limit));
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, 0));
 }
 
 void test_pack_filelimit__cleanup(void)
 {
-	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, original_mwindow_file_limit));
+	git_buf path = GIT_BUF_INIT;
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, _original_mwindow_file_limit));
+
+	cl_git_pass(git_buf_joinpath(&path, clar_sandbox_path(), "repo.git"));
+	cl_fixture_cleanup(path.ptr);
+	git_buf_dispose(&path);
+}
+
+/*
+ * Create a packfile with one commit, one tree, and two blobs. The first blob
+ * (README.md) has the same content in all commits, but the second one
+ * (file.txt) has a different content in each commit.
+ */
+void create_packfile_commit(
+		git_repository *repo,
+		git_oid *out_commit_id,
+		git_oid *parent_id,
+		size_t commit_index,
+		size_t commit_count)
+{
+	git_buf file_contents = GIT_BUF_INIT;
+	git_treebuilder *treebuilder;
+	git_packbuilder *packbuilder;
+	git_signature *s;
+	git_oid oid, tree_id, commit_id;
+	const git_oid *parents[] = { parent_id };
+	size_t parent_count = parent_id ? 1 : 0;
+
+	cl_git_pass(git_treebuilder_new(&treebuilder, repo, NULL));
+
+	cl_git_pass(git_blob_create_from_buffer(&oid, repo, "", 0));
+	cl_git_pass(git_treebuilder_insert(NULL, treebuilder, "README.md", &oid, 0100644));
+
+	cl_git_pass(git_buf_printf(&file_contents, "Commit %zd/%zd", commit_index, commit_count));
+	cl_git_pass(git_blob_create_from_buffer(&oid, repo, file_contents.ptr, file_contents.size));
+	cl_git_pass(git_treebuilder_insert(NULL, treebuilder, "file.txt", &oid, 0100644));
+
+	cl_git_pass(git_treebuilder_write(&tree_id, treebuilder));
+	cl_git_pass(git_signature_now(&s, "alice", "alice@example.com"));
+	cl_git_pass(git_commit_create_from_ids(&commit_id, repo, "refs/heads/master", s, s,
+			NULL, file_contents.ptr, &tree_id, parent_count, parents));
+
+	cl_git_pass(git_packbuilder_new(&packbuilder, repo));
+	cl_git_pass(git_packbuilder_insert_commit(packbuilder, &commit_id));
+	cl_git_pass(git_packbuilder_write(packbuilder, NULL, 0, NULL, NULL));
+
+	cl_git_pass(git_oid_cpy(out_commit_id, &commit_id));
+
+	git_buf_dispose(&file_contents);
+	git_treebuilder_free(treebuilder);
+	git_packbuilder_free(packbuilder);
+	git_signature_free(s);
 }
 
-void test_pack_filelimit__open_repo_with_1025_packfiles(void)
+void test_pack_filelimit__open_repo_with_multiple_packfiles(void)
 {
+	git_buf path = GIT_BUF_INIT;
 	git_mwindow_ctl *ctl = &git_mwindow__mem_ctl;
 	git_repository *repo;
 	git_revwalk *walk;
-	git_oid id;
-	int i;
+	git_oid id, *parent_id = NULL;
+	size_t i;
+	const size_t commit_count = 16;
 	unsigned int open_windows;
 
 	/*
-	 * This repository contains 1025 packfiles, each with one commit, one tree,
-	 * and two blobs. The first blob (README.md) has the same content in all
-	 * commits, but the second one (file.txt) has a different content in each
-	 * commit.
+	 * Create a repository and populate it with 16 commits, each in its own
+	 * packfile.
 	 */
-	cl_git_pass(git_repository_open(&repo, cl_fixture("1025.git")));
-	cl_git_pass(git_revwalk_new(&walk, repo));
+	cl_git_pass(git_buf_joinpath(&path, clar_sandbox_path(), "repo.git"));
+	cl_git_pass(git_repository_init(&repo, path.ptr, true));
+	for (i = 1; i <= commit_count; ++i) {
+		create_packfile_commit(repo, &id, parent_id, i, commit_count);
+		parent_id = &id;
+	}
 
+	cl_git_pass(git_revwalk_new(&walk, repo));
 	cl_git_pass(git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL));
 	cl_git_pass(git_revwalk_push_ref(walk, "refs/heads/master"));
 
 	/*
-	 * Walking the tree requires opening each of the 1025 packfiles. This should
-	 * work in all platforms, including those where the default limit of open
-	 * file descriptors is small (e.g. 256 in macOS).
+	 * Walking the repository requires eventually opening each of the packfiles.
 	 */
 	i = 0;
 	while (git_revwalk_next(&id, walk) == 0)
 		++i;
-	cl_assert_equal_i(1025, i);
+	cl_assert_equal_i(commit_count, i);
 
 	cl_git_pass(git_mutex_lock(&git__mwindow_mutex));
 	/*
@@ -65,8 +130,9 @@ void test_pack_filelimit__open_repo_with_1025_packfiles(void)
 	open_windows = ctl->open_windows;
 	cl_git_pass(git_mutex_unlock(&git__mwindow_mutex));
 
-	cl_assert_equal_i(mwindow_file_limit, open_windows);
+	cl_assert_equal_i(_expected_open_mwindow_files, open_windows);
 
+	git_buf_dispose(&path);
 	git_revwalk_free(walk);
 	git_repository_free(repo);
 }

tests/resources/1025.git/HEAD

-ref: refs/heads/master

tests/resources/1025.git/config

-[core]
-	bare = true
-	repositoryformatversion = 0
-	filemode = true

tests/resources/1025.git/description

-Unnamed repository; edit this file 'description' to name the repository.

tests/resources/1025.git/hooks/README.sample

-#!/bin/sh
-#
-# Place appropriately named executable hook scripts into this directory
-# to intercept various actions that git takes.  See `git help hooks` for
-# more information.

tests/resources/1025.git/info/exclude

-# File patterns to ignore; see `git help ignore` for more information.
-# Lines that start with '#' are comments.