Merge pull request #3219 from libgit2/cmn/racy-diff

Zero out racily-clean entries' file_size

8 files changed, 143 insertions, 4 deletions

diff --git a/tests/checkout/checkout_helpers.c b/tests/checkout/checkout_helpers.c
index 06b4e0682..f6e36d39b 100644
--- a/tests/checkout/checkout_helpers.c
+++ b/tests/checkout/checkout_helpers.c
@@ -2,6 +2,7 @@
 #include "checkout_helpers.h"
 #include "refs.h"
 #include "fileops.h"
+#include "index.h"
 
 void assert_on_branch(git_repository *repo, const char *branch)
 {
@@ -128,3 +129,24 @@ int checkout_count_callback(
 
 	return 0;
 }
+
+void tick_index(git_index *index)
+{
+	int index_fd;
+	git_time_t ts;
+	struct timeval times[2];
+
+	cl_assert(index->on_disk);
+	cl_assert(git_index_path(index));
+
+	cl_git_pass(git_index_read(index, true));
+	ts = index->stamp.mtime;
+
+	times[0].tv_sec  = ts;
+	times[0].tv_usec = 0;
+	times[1].tv_sec  = ts + 1;
+	times[1].tv_usec = 0;
+
+	cl_git_pass(p_utimes(git_index_path(index), times));
+	cl_git_pass(git_index_read(index, true));
+}
diff --git a/tests/checkout/checkout_helpers.h b/tests/checkout/checkout_helpers.h
index 705ee903d..6058a196c 100644
--- a/tests/checkout/checkout_helpers.h
+++ b/tests/checkout/checkout_helpers.h
@@ -27,3 +27,5 @@ extern int checkout_count_callback(
 	const git_diff_file *target,
 	const git_diff_file *workdir,
 	void *payload);
+
+extern void tick_index(git_index *index);
diff --git a/tests/checkout/crlf.c b/tests/checkout/crlf.c
index 381b04013..61459b3a4 100644
--- a/tests/checkout/crlf.c
+++ b/tests/checkout/crlf.c
@@ -4,6 +4,7 @@
 
 #include "git2/checkout.h"
 #include "repository.h"
+#include "index.h"
 #include "posix.h"
 
 static git_repository *g_repo;
@@ -40,9 +41,10 @@ void test_checkout_crlf__autocrlf_false_index_size_is_unfiltered_size(void)
 
 	cl_repo_set_bool(g_repo, "core.autocrlf", false);
 
-	git_checkout_head(g_repo, &opts);
-
 	git_repository_index(&index, g_repo);
+	tick_index(index);
+
+	git_checkout_head(g_repo, &opts);
 
 	cl_assert((entry = git_index_get_bypath(index, "all-lf", 0)) != NULL);
 	cl_assert(entry->file_size == strlen(ALL_LF_TEXT_RAW));
@@ -140,9 +142,10 @@ void test_checkout_crlf__autocrlf_true_index_size_is_filtered_size(void)
 
 	cl_repo_set_bool(g_repo, "core.autocrlf", true);
 
-	git_checkout_head(g_repo, &opts);
-
 	git_repository_index(&index, g_repo);
+	tick_index(index);
+
+	git_checkout_head(g_repo, &opts);
 
 	cl_assert((entry = git_index_get_bypath(index, "all-lf", 0)) != NULL);
 
diff --git a/tests/core/posix.c b/tests/core/posix.c
index 1cef937cd..5a9e24899 100644
--- a/tests/core/posix.c
+++ b/tests/core/posix.c
@@ -97,3 +97,52 @@ void test_core_posix__inet_pton(void)
 	cl_git_fail(p_inet_pton(5, "315.124", NULL)); /* AF_CHAOS */
 	cl_assert_equal_i(EAFNOSUPPORT, errno);
 }
+
+void test_core_posix__utimes(void)
+{
+	struct timeval times[2];
+	struct stat st;
+	time_t curtime;
+	int fd;
+
+	/* test p_utimes */
+	times[0].tv_sec = 1234567890;
+	times[0].tv_usec = 0;
+	times[1].tv_sec = 1234567890;
+	times[1].tv_usec = 0;
+
+	cl_git_mkfile("foo", "Dummy file.");
+	cl_must_pass(p_utimes("foo", times));
+
+	p_stat("foo", &st);
+	cl_assert_equal_i(1234567890, st.st_atime);
+	cl_assert_equal_i(1234567890, st.st_mtime);
+
+
+	/* test p_futimes */
+	times[0].tv_sec = 1414141414;
+	times[0].tv_usec = 0;
+	times[1].tv_sec = 1414141414;
+	times[1].tv_usec = 0;
+
+	cl_must_pass(fd = p_open("foo", O_RDWR));
+	cl_must_pass(p_futimes(fd, times));
+	p_close(fd);
+
+	p_stat("foo", &st);
+	cl_assert_equal_i(1414141414, st.st_atime);
+	cl_assert_equal_i(1414141414, st.st_mtime);
+
+
+	/* test p_utimes with current time, assume that
+	 * it takes < 5 seconds to get the time...!
+	 */
+	cl_must_pass(p_utimes("foo", NULL));
+
+	curtime = time(NULL);
+	p_stat("foo", &st);
+	cl_assert((st.st_atime - curtime) < 5);
+	cl_assert((st.st_mtime - curtime) < 5);
+
+	p_unlink("foo");
+}
diff --git a/tests/diff/racy.c b/tests/diff/racy.c
new file mode 100644
index 000000000..a109f8c3b
--- /dev/null
+++ b/tests/diff/racy.c
@@ -0,0 +1,39 @@
+#include "clar_libgit2.h"
+
+#include "buffer.h"
+
+static git_repository *g_repo;
+
+void test_diff_racy__initialize(void)
+{
+	cl_git_pass(git_repository_init(&g_repo, "diff_racy", false));
+}
+
+void test_diff_racy__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+void test_diff_racy__diff(void)
+{
+	git_index *index;
+	git_diff *diff;
+	git_buf path = GIT_BUF_INIT;
+
+	cl_git_pass(git_buf_joinpath(&path, git_repository_workdir(g_repo), "A"));
+	cl_git_mkfile(path.ptr, "A");
+
+	/* Put 'A' into the index */
+	cl_git_pass(git_repository_index(&index, g_repo));
+	cl_git_pass(git_index_add_bypath(index, "A"));
+	cl_git_pass(git_index_write(index));
+
+	cl_git_pass(git_diff_index_to_workdir(&diff, g_repo, index, NULL));
+	cl_assert_equal_i(0, git_diff_num_deltas(diff));
+
+	/* Change its contents quickly, so we get the same timestamp */
+	cl_git_mkfile(path.ptr, "B");
+
+	cl_git_pass(git_diff_index_to_workdir(&diff, g_repo, index, NULL));
+	cl_assert_equal_i(1, git_diff_num_deltas(diff));
+}
diff --git a/tests/diff/workdir.c b/tests/diff/workdir.c
index 5d6ebed95..6b72f3286 100644
--- a/tests/diff/workdir.c
+++ b/tests/diff/workdir.c
@@ -2,6 +2,7 @@
 #include "diff_helpers.h"
 #include "repository.h"
 #include "git2/sys/diff.h"
+#include "../checkout/checkout_helpers.h"
 
 static git_repository *g_repo = NULL;
 
@@ -1583,6 +1584,7 @@ void test_diff_workdir__can_update_index(void)
 	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
 	git_diff *diff = NULL;
 	git_diff_perfdata perf = GIT_DIFF_PERFDATA_INIT;
+	git_index *index;
 
 	g_repo = cl_git_sandbox_init("status");
 
@@ -1607,6 +1609,10 @@ void test_diff_workdir__can_update_index(void)
 	/* now allow diff to update stat cache */
 	opts.flags |= GIT_DIFF_UPDATE_INDEX;
 
+	/* advance a tick for the index so we don't re-calculate racily-clean entries */
+	cl_git_pass(git_repository_index__weakptr(&index, g_repo));
+	tick_index(index);
+
 	basic_diff_status(&diff, &opts);
 
 	cl_git_pass(git_diff_get_perfdata(&perf, diff));
diff --git a/tests/merge/workdir/dirty.c b/tests/merge/workdir/dirty.c
index b66225d1f..30c404b70 100644
--- a/tests/merge/workdir/dirty.c
+++ b/tests/merge/workdir/dirty.c
@@ -2,6 +2,7 @@
 #include "git2/merge.h"
 #include "buffer.h"
 #include "merge.h"
+#include "index.h"
 #include "../merge_helpers.h"
 #include "posix.h"
 
@@ -231,9 +232,20 @@ static int merge_differently_filtered_files(char *files[])
 	cl_git_pass(git_reference_peel(&head_object, head, GIT_OBJ_COMMIT));
 	cl_git_pass(git_reset(repo, head_object, GIT_RESET_HARD, NULL));
 
+	/* Emulate checkout with a broken or misconfigured filter:  modify some
+	 * files on-disk and then update the index with the updated file size
+	 * and time, as if some filter applied them.  These files should not be
+	 * treated as dirty since we created them.
+	 *
+	 * (Make sure to update the index stamp to defeat racy-git protections
+	 * trying to sanity check the files in the index; those would rehash the
+	 * files, showing them as dirty, the exact mechanism we're trying to avoid.)
+	 */
+
 	write_files(files);
 	hack_index(files);
 
+	repo_index->stamp.mtime = time(NULL) + 1;
 	cl_git_pass(git_index_write(repo_index));
 
 	error = merge_branch();
diff --git a/tests/status/worktree.c b/tests/status/worktree.c
index 3b18ae6c0..f8d1f7f54 100644
--- a/tests/status/worktree.c
+++ b/tests/status/worktree.c
@@ -6,6 +6,7 @@
 #include "util.h"
 #include "path.h"
 #include "../diff/diff_helpers.h"
+#include "../checkout/checkout_helpers.h"
 #include "git2/sys/diff.h"
 
 /**
@@ -956,6 +957,7 @@ void test_status_worktree__update_stat_cache_0(void)
 	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
 	git_status_list *status;
 	git_diff_perfdata perf = GIT_DIFF_PERFDATA_INIT;
+	git_index *index;
 
 	opts.flags = GIT_STATUS_OPT_DEFAULTS;
 
@@ -967,6 +969,10 @@ void test_status_worktree__update_stat_cache_0(void)
 
 	git_status_list_free(status);
 
+	/* tick the index so we avoid recalculating racily-clean entries */
+	cl_git_pass(git_repository_index__weakptr(&index, repo));
+	tick_index(index);
+
 	opts.flags |= GIT_STATUS_OPT_UPDATE_INDEX;
 
 	cl_git_pass(git_status_list_new(&status, repo, &opts));