thodg/libgit2

diff --git a/include/git2/diff.h b/include/git2/diff.h
index 675c209..8147fd3 100644
--- a/include/git2/diff.h
+++ b/include/git2/diff.h
@@ -152,6 +152,12 @@ typedef enum {
 	 */
 	GIT_DIFF_UPDATE_INDEX = (1u << 15),
 
+	/** Include unreadable files in the diff */
+	GIT_DIFF_INCLUDE_UNREADABLE = (1u << 16),
+	
+	/** Include unreadable files in the diff */
+	GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED = (1u << 17),
+
 	/*
 	 * Options controlling how output will be generated
 	 */
@@ -237,6 +243,7 @@ typedef enum {
 	GIT_DELTA_IGNORED = 6,    /**< entry is ignored item in workdir */
 	GIT_DELTA_UNTRACKED = 7,  /**< entry is untracked item in workdir */
 	GIT_DELTA_TYPECHANGE = 8, /**< type of entry changed between old and new */
+	GIT_DELTA_UNREADABLE = 9, /**< entry is unreadable */
 } git_delta_t;
 
 /**
diff --git a/include/git2/status.h b/include/git2/status.h
index effe5e1..3c86e5d 100644
--- a/include/git2/status.h
+++ b/include/git2/status.h
@@ -43,6 +43,7 @@ typedef enum {
 	GIT_STATUS_WT_DELETED       = (1u << 9),
 	GIT_STATUS_WT_TYPECHANGE    = (1u << 10),
 	GIT_STATUS_WT_RENAMED       = (1u << 11),
+	GIT_STATUS_WT_UNREADABLE    = (1u << 12),
 
 	GIT_STATUS_IGNORED          = (1u << 14),
 } git_status_t;
@@ -133,20 +134,22 @@ typedef enum {
  * together as `GIT_STATUS_OPT_DEFAULTS` if you want them as a baseline.
  */
 typedef enum {
-	GIT_STATUS_OPT_INCLUDE_UNTRACKED        = (1u << 0),
-	GIT_STATUS_OPT_INCLUDE_IGNORED          = (1u << 1),
-	GIT_STATUS_OPT_INCLUDE_UNMODIFIED       = (1u << 2),
-	GIT_STATUS_OPT_EXCLUDE_SUBMODULES       = (1u << 3),
-	GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS   = (1u << 4),
-	GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH   = (1u << 5),
-	GIT_STATUS_OPT_RECURSE_IGNORED_DIRS     = (1u << 6),
-	GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX    = (1u << 7),
-	GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR = (1u << 8),
-	GIT_STATUS_OPT_SORT_CASE_SENSITIVELY    = (1u << 9),
-	GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY  = (1u << 10),
-	GIT_STATUS_OPT_RENAMES_FROM_REWRITES    = (1u << 11),
-	GIT_STATUS_OPT_NO_REFRESH               = (1u << 12),
-	GIT_STATUS_OPT_UPDATE_INDEX             = (1u << 13),
+	GIT_STATUS_OPT_INCLUDE_UNTRACKED                = (1u << 0),
+	GIT_STATUS_OPT_INCLUDE_IGNORED                  = (1u << 1),
+	GIT_STATUS_OPT_INCLUDE_UNMODIFIED               = (1u << 2),
+	GIT_STATUS_OPT_EXCLUDE_SUBMODULES               = (1u << 3),
+	GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS           = (1u << 4),
+	GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH           = (1u << 5),
+	GIT_STATUS_OPT_RECURSE_IGNORED_DIRS             = (1u << 6),
+	GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX            = (1u << 7),
+	GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR         = (1u << 8),
+	GIT_STATUS_OPT_SORT_CASE_SENSITIVELY            = (1u << 9),
+	GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY          = (1u << 10),
+	GIT_STATUS_OPT_RENAMES_FROM_REWRITES            = (1u << 11),
+	GIT_STATUS_OPT_NO_REFRESH                       = (1u << 12),
+	GIT_STATUS_OPT_UPDATE_INDEX                     = (1u << 13),
+	GIT_STATUS_OPT_INCLUDE_UNREADABLE               = (1u << 14),
+	GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED  = (1u << 15),
 } git_status_opt_t;
 
 #define GIT_STATUS_OPT_DEFAULTS \
diff --git a/include/git2/types.h b/include/git2/types.h
index 6295ebb..76175b6 100644
--- a/include/git2/types.h
+++ b/include/git2/types.h
@@ -198,12 +198,12 @@ typedef enum {
 
 /** Valid modes for index and tree entries. */
 typedef enum {
-	GIT_FILEMODE_NEW					= 0000000,
-	GIT_FILEMODE_TREE					= 0040000,
-	GIT_FILEMODE_BLOB					= 0100644,
-	GIT_FILEMODE_BLOB_EXECUTABLE		= 0100755,
-	GIT_FILEMODE_LINK					= 0120000,
-	GIT_FILEMODE_COMMIT					= 0160000,
+	GIT_FILEMODE_UNREADABLE          = 0000000,
+	GIT_FILEMODE_TREE                = 0040000,
+	GIT_FILEMODE_BLOB                = 0100644,
+	GIT_FILEMODE_BLOB_EXECUTABLE     = 0100755,
+	GIT_FILEMODE_LINK                = 0120000,
+	GIT_FILEMODE_COMMIT              = 0160000,
 } git_filemode_t;
 
 typedef struct git_refspec git_refspec;
diff --git a/src/checkout.c b/src/checkout.c
index adb3c81..f25a6ef 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -119,6 +119,7 @@ static int checkout_notify(
 		case GIT_DELTA_ADDED:
 		case GIT_DELTA_IGNORED:
 		case GIT_DELTA_UNTRACKED:
+		case GIT_DELTA_UNREADABLE:
 			target = &delta->new_file;
 			break;
 		case GIT_DELTA_DELETED:
@@ -2143,6 +2144,7 @@ int git_checkout_iterator(
 
 	diff_opts.flags =
 		GIT_DIFF_INCLUDE_UNMODIFIED |
+		GIT_DIFF_INCLUDE_UNREADABLE |
 		GIT_DIFF_INCLUDE_UNTRACKED |
 		GIT_DIFF_RECURSE_UNTRACKED_DIRS | /* needed to match baseline */
 		GIT_DIFF_INCLUDE_IGNORED |
diff --git a/src/diff.c b/src/diff.c
index 325c599..2691d7c 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -92,6 +92,10 @@ static int diff_delta__from_one(
 	if (status == GIT_DELTA_UNTRACKED &&
 		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_UNTRACKED))
 		return 0;
+	
+	if (status == GIT_DELTA_UNREADABLE &&
+		DIFF_FLAG_ISNT_SET(diff, GIT_DIFF_INCLUDE_UNREADABLE))
+		return 0;
 
 	if (!git_pathspec__match(
 			&diff->pathspec, entry->path,
@@ -196,6 +200,7 @@ static git_diff_delta *diff_delta__last_for_item(
 		if (git_oid__cmp(&delta->new_file.id, &item->id) == 0)
 			return delta;
 		break;
+	case GIT_DELTA_UNREADABLE:
 	case GIT_DELTA_UNTRACKED:
 		if (diff->strcomp(delta->new_file.path, item->path) == 0 &&
 			git_oid__cmp(&delta->new_file.id, &item->id) == 0)
@@ -293,6 +298,10 @@ bool git_diff_delta__should_skip(
 		(flags & GIT_DIFF_INCLUDE_UNTRACKED) == 0)
 		return true;
 
+	if (delta->status == GIT_DELTA_UNREADABLE &&
+		(flags & GIT_DIFF_INCLUDE_UNREADABLE) == 0)
+		return true;
+
 	return false;
 }
 
@@ -734,6 +743,11 @@ static int maybe_modified(
 	else if (GIT_MODE_TYPE(omode) != GIT_MODE_TYPE(nmode)) {
 		if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_TYPECHANGE))
 			status = GIT_DELTA_TYPECHANGE;
+		else if (nmode == GIT_FILEMODE_UNREADABLE) {
+			if (!(error = diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem)))
+				error = diff_delta__from_one(diff, GIT_DELTA_UNREADABLE, nitem);
+			return error;
+		}
 		else {
 			if (!(error = diff_delta__from_one(diff, GIT_DELTA_DELETED, oitem)))
 				error = diff_delta__from_one(diff, GIT_DELTA_ADDED, nitem);
@@ -954,6 +968,13 @@ static int handle_unmatched_new_item(
 		}
 	}
 
+	else if (nitem->mode == GIT_FILEMODE_UNREADABLE) {
+		if (DIFF_FLAG_IS_SET(diff, GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED))
+			delta_type = GIT_DELTA_UNTRACKED;
+		else
+			delta_type = GIT_DELTA_UNREADABLE;
+	}
+
 	/* Actually create the record for this item if necessary */
 	if ((error = diff_delta__from_one(diff, delta_type, nitem)) != 0)
 		return error;
diff --git a/src/diff_file.c b/src/diff_file.c
index f2a1d50..96be094 100644
--- a/src/diff_file.c
+++ b/src/diff_file.c
@@ -112,6 +112,7 @@ int git_diff_file_content__init_from_diff(
 		has_data = !use_old &&
 			(diff->opts.flags & GIT_DIFF_SHOW_UNTRACKED_CONTENT) != 0;
 		break;
+	case GIT_DELTA_UNREADABLE:
 	case GIT_DELTA_MODIFIED:
 	case GIT_DELTA_COPIED:
 	case GIT_DELTA_RENAMED:
diff --git a/src/diff_print.c b/src/diff_print.c
index bb925ef..fb62a5f 100644
--- a/src/diff_print.c
+++ b/src/diff_print.c
@@ -82,14 +82,15 @@ char git_diff_status_char(git_delta_t status)
 	char code;
 
 	switch (status) {
-	case GIT_DELTA_ADDED:     code = 'A'; break;
-	case GIT_DELTA_DELETED:   code = 'D'; break;
-	case GIT_DELTA_MODIFIED:  code = 'M'; break;
-	case GIT_DELTA_RENAMED:   code = 'R'; break;
-	case GIT_DELTA_COPIED:    code = 'C'; break;
-	case GIT_DELTA_IGNORED:   code = 'I'; break;
-	case GIT_DELTA_UNTRACKED: code = '?'; break;
-	default:                  code = ' '; break;
+	case GIT_DELTA_ADDED:      code = 'A'; break;
+	case GIT_DELTA_DELETED:    code = 'D'; break;
+	case GIT_DELTA_MODIFIED:   code = 'M'; break;
+	case GIT_DELTA_RENAMED:    code = 'R'; break;
+	case GIT_DELTA_COPIED:     code = 'C'; break;
+	case GIT_DELTA_IGNORED:    code = 'I'; break;
+	case GIT_DELTA_UNTRACKED:  code = '?'; break;
+	case GIT_DELTA_UNREADABLE: code = 'X'; break;
+	default:                   code = ' '; break;
 	}
 
 	return code;
@@ -441,6 +442,7 @@ static int diff_print_patch_file(
 	if (S_ISDIR(delta->new_file.mode) ||
 		delta->status == GIT_DELTA_UNMODIFIED ||
 		delta->status == GIT_DELTA_IGNORED ||
+		delta->status == GIT_DELTA_UNREADABLE ||
 		(delta->status == GIT_DELTA_UNTRACKED &&
 		 (pi->flags & GIT_DIFF_SHOW_UNTRACKED_CONTENT) == 0))
 		return 0;
diff --git a/src/diff_tform.c b/src/diff_tform.c
index a2dab0a..423a0ca 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -114,7 +114,7 @@ static git_diff_delta *diff_delta__merge_like_cgit_reversed(
 	if ((dup = diff_delta__dup(a, pool)) == NULL)
 		return NULL;
 
-	if (b->status == GIT_DELTA_UNMODIFIED || b->status == GIT_DELTA_UNTRACKED)
+	if (b->status == GIT_DELTA_UNMODIFIED || b->status == GIT_DELTA_UNTRACKED || b->status == GIT_DELTA_UNREADABLE)
 		return dup;
 
 	if (dup->status == GIT_DELTA_DELETED) {
@@ -732,6 +732,7 @@ static bool is_rename_source(
 	switch (delta->status) {
 	case GIT_DELTA_ADDED:
 	case GIT_DELTA_UNTRACKED:
+	case GIT_DELTA_UNREADABLE:
 	case GIT_DELTA_IGNORED:
 		return false;
 
@@ -786,6 +787,7 @@ GIT_INLINE(bool) delta_is_new_only(git_diff_delta *delta)
 {
 	return (delta->status == GIT_DELTA_ADDED ||
 			delta->status == GIT_DELTA_UNTRACKED ||
+			delta->status == GIT_DELTA_UNREADABLE ||
 			delta->status == GIT_DELTA_IGNORED);
 }
 
diff --git a/src/path.c b/src/path.c
index 6d0b374..4837b01 100644
--- a/src/path.c
+++ b/src/path.c
@@ -1116,7 +1116,15 @@ int git_path_dirload_with_stat(
 				git_vector_remove(contents, i--);
 				continue;
 			}
-
+			/* Treat the file as unreadable if we get any other error */
+			if (error != 0) {
+				giterr_clear();
+				error = 0;
+				memset(&ps->st, 0, sizeof(ps->st));
+				ps->st.st_mode = GIT_FILEMODE_UNREADABLE;
+				continue;
+			}
+			
 			break;
 		}
 
diff --git a/src/status.c b/src/status.c
index 8d7612f..cb24900 100644
--- a/src/status.c
+++ b/src/status.c
@@ -62,6 +62,9 @@ static unsigned int workdir_delta2status(
 	case GIT_DELTA_UNTRACKED:
 		st = GIT_STATUS_WT_NEW;
 		break;
+	case GIT_DELTA_UNREADABLE:
+		st = GIT_STATUS_WT_UNREADABLE;
+		break;
 	case GIT_DELTA_DELETED:
 		st = GIT_STATUS_WT_DELETED;
 		break;
@@ -310,6 +313,10 @@ int git_status_list_new(
 		diffopt.flags = diffopt.flags | GIT_DIFF_IGNORE_SUBMODULES;
 	if ((flags & GIT_STATUS_OPT_UPDATE_INDEX) != 0)
 		diffopt.flags = diffopt.flags | GIT_DIFF_UPDATE_INDEX;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNREADABLE) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNREADABLE;
+	if ((flags & GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED) != 0)
+		diffopt.flags = diffopt.flags | GIT_DIFF_INCLUDE_UNREADABLE_AS_UNTRACKED;
 
 	if ((flags & GIT_STATUS_OPT_RENAMES_FROM_REWRITES) != 0)
 		findopt.flags = findopt.flags |
@@ -329,8 +336,9 @@ int git_status_list_new(
 
 	if (show != GIT_STATUS_SHOW_INDEX_ONLY) {
 		if ((error = git_diff_index_to_workdir(
-				&status->idx2wd, repo, index, &diffopt)) < 0)
+				&status->idx2wd, repo, index, &diffopt)) < 0) {
 			goto done;
+		}
 
 		if ((flags & GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR) != 0 &&
 			(error = git_diff_find_similar(status->idx2wd, &findopt)) < 0)
@@ -407,8 +415,9 @@ int git_status_foreach_ext(
 	size_t i;
 	int error = 0;
 
-	if ((error = git_status_list_new(&status, repo, opts)) < 0)
+	if ((error = git_status_list_new(&status, repo, opts)) < 0) {
 		return error;
+	}
 
 	git_vector_foreach(&status->paired, i, status_entry) {
 		const char *path = status_entry->head_to_index ?
diff --git a/tests/status/status_helpers.c b/tests/status/status_helpers.c
index 0882792..5d13caa 100644
--- a/tests/status/status_helpers.c
+++ b/tests/status/status_helpers.c
@@ -82,6 +82,9 @@ int cb_status__print(
 	if (status_flags & GIT_STATUS_IGNORED) {
 		wstatus = 'I'; wcount++;
 	}
+	if (status_flags & GIT_STATUS_WT_UNREADABLE) {
+		wstatus = 'X'; wcount++;
+	}
 
 	fprintf(stderr, "%c%c %s (%d/%d%s)\n",
 			istatus, wstatus, path, icount, wcount,
diff --git a/tests/status/worktree.c b/tests/status/worktree.c
index ca9068a..2e86c03 100644
--- a/tests/status/worktree.c
+++ b/tests/status/worktree.c
@@ -935,3 +935,102 @@ void test_status_worktree__update_stat_cache_0(void)
 
 	git_status_list_free(status);
 }
+
+void test_status_worktree__unreadable(void)
+{
+	const char *expected_paths[] = { "no_permission/foo" };
+	const unsigned int expected_statuses[] = {GIT_STATUS_WT_UNREADABLE};
+
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
+	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
+	status_entry_counts counts = {0};
+
+	/* Create directory with no read permission */
+	cl_git_pass(git_futils_mkdir_r("empty_standard_repo/no_permission", NULL, 0777));
+	cl_git_mkfile("empty_standard_repo/no_permission/foo", "dummy");
+	p_chmod("empty_standard_repo/no_permission", 0644);
+
+	counts.expected_entry_count = 1;
+	counts.expected_paths = expected_paths;
+	counts.expected_statuses = expected_statuses;
+
+	opts.show = GIT_STATUS_SHOW_WORKDIR_ONLY;
+	opts.flags = GIT_STATUS_OPT_DEFAULTS | GIT_STATUS_OPT_INCLUDE_UNREADABLE;
+
+	cl_git_pass(
+		git_status_foreach_ext(repo, &opts, cb_status__normal, &counts) );
+
+	/* Restore permissions so we can cleanup :) */
+	p_chmod("empty_standard_repo/no_permission", 0777);
+
+	cl_assert_equal_i(counts.expected_entry_count, counts.entry_count);
+	cl_assert_equal_i(0, counts.wrong_status_flags_count);
+	cl_assert_equal_i(0, counts.wrong_sorted_path);
+}
+
+void test_status_worktree__unreadable_not_included(void)
+{
+	const char *expected_paths[] = { "no_permission/" };
+	const unsigned int expected_statuses[] = {GIT_STATUS_WT_NEW};
+
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
+	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
+	status_entry_counts counts = {0};
+
+	/* Create directory with no read permission */
+	cl_git_pass(git_futils_mkdir_r("empty_standard_repo/no_permission", NULL, 0777));
+	cl_git_mkfile("empty_standard_repo/no_permission/foo", "dummy");
+	p_chmod("empty_standard_repo/no_permission", 0644);
+
+	counts.expected_entry_count = 1;
+	counts.expected_paths = expected_paths;
+	counts.expected_statuses = expected_statuses;
+
+	opts.show = GIT_STATUS_SHOW_WORKDIR_ONLY;
+	opts.flags = (GIT_STATUS_OPT_INCLUDE_IGNORED | GIT_STATUS_OPT_INCLUDE_UNTRACKED);
+
+	cl_git_pass(
+		git_status_foreach_ext(repo, &opts, cb_status__normal, &counts) );
+
+	/* Restore permissions so we can cleanup :) */
+	p_chmod("empty_standard_repo/no_permission", 0777);
+
+	cl_assert_equal_i(counts.expected_entry_count, counts.entry_count);
+	cl_assert_equal_i(0, counts.wrong_status_flags_count);
+	cl_assert_equal_i(0, counts.wrong_sorted_path);
+}
+
+void test_status_worktree__unreadable_as_untracked(void)
+{
+	const char *expected_paths[] = { "no_permission/foo" };
+	const unsigned int expected_statuses[] = {GIT_STATUS_WT_NEW};
+
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
+	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
+	status_entry_counts counts = {0};
+
+	/* Create directory with no read permission */
+	cl_git_pass(git_futils_mkdir_r("empty_standard_repo/no_permission", NULL, 0777));
+	cl_git_mkfile("empty_standard_repo/no_permission/foo", "dummy");
+	p_chmod("empty_standard_repo/no_permission", 0644);
+
+	counts.expected_entry_count = 1;
+	counts.expected_paths = expected_paths;
+	counts.expected_statuses = expected_statuses;
+
+	opts.show = GIT_STATUS_SHOW_WORKDIR_ONLY;
+	opts.flags = GIT_STATUS_OPT_DEFAULTS |
+		GIT_STATUS_OPT_INCLUDE_UNREADABLE |
+		GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED;
+
+	cl_git_pass(
+		git_status_foreach_ext(repo, &opts, cb_status__normal, &counts) );
+
+	/* Restore permissions so we can cleanup :) */
+	p_chmod("empty_standard_repo/no_permission", 0777);
+
+	cl_assert_equal_i(counts.expected_entry_count, counts.entry_count);
+	cl_assert_equal_i(0, counts.wrong_status_flags_count);
+	cl_assert_equal_i(0, counts.wrong_sorted_path);
+}
+