Three submodule status bug fixes

1. Fix sort order problem with submodules where "mod" was sorting
   after "mod-plus" because they were being sorted as "mod/" and
   "mod-plus/".  This involved pushing the "contains a .git entry"
   test significantly lower in the stack.
2. Reinstate behavior that a directory which contains a .git entry
   will be treated as a submodule during iteration even if it is
   not yet added to the .gitmodules.
3. Now that any directory containing .git is reported as submodule,
   we have to be more careful checking for GIT_EEXISTS when we
   do a submodule lookup, because that is the error code that is
   returned by git_submodule_lookup when you try to look up a
   directory containing .git that has no record in gitmodules or
   the index.

4 files changed, 26 insertions, 8 deletions

diff --git a/src/diff.c b/src/diff.c
index fc37d139d..fb69f8920 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -512,13 +512,17 @@ static int maybe_modified(
 			status = GIT_DELTA_UNMODIFIED;
 
 		else if (S_ISGITLINK(nmode)) {
+			int err;
 			git_submodule *sub;
 
 			if ((diff->opts.flags & GIT_DIFF_IGNORE_SUBMODULES) != 0)
 				status = GIT_DELTA_UNMODIFIED;
-			else if (git_submodule_lookup(&sub, diff->repo, nitem->path) < 0)
-				return -1;
-			else if (git_submodule_ignore(sub) == GIT_SUBMODULE_IGNORE_ALL)
+			else if ((err = git_submodule_lookup(&sub, diff->repo, nitem->path)) < 0) {
+				if (err == GIT_EEXISTS)
+					status = GIT_DELTA_UNMODIFIED;
+				else
+					return err;
+			} else if (git_submodule_ignore(sub) == GIT_SUBMODULE_IGNORE_ALL)
 				status = GIT_DELTA_UNMODIFIED;
 			else {
 				unsigned int sm_status = 0;
diff --git a/src/diff_output.c b/src/diff_output.c
index b938cc06d..fba6129b7 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -299,7 +299,12 @@ static int get_workdir_sm_content(
 
 	if ((error = git_submodule_lookup(&sm, ctxt->repo, file->path)) < 0 ||
 		(error = git_submodule_status(&sm_status, sm)) < 0)
+	{
+		/* GIT_EEXISTS means a "submodule" that has not been git added */
+		if (error == GIT_EEXISTS)
+			error = 0;
 		return error;
+	}
 
 	/* update OID if we didn't have it previously */
 	if ((file->flags & GIT_DIFF_FLAG_VALID_OID) == 0) {
diff --git a/src/iterator.c b/src/iterator.c
index b15bcedd8..805a3c987 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -1150,11 +1150,13 @@ static int workdir_iterator__update_entry(workdir_iterator *wi)
 		return 0;
 
 	/* detect submodules */
-
 	error = git_submodule_lookup(NULL, wi->base.repo, wi->entry.path);
 	if (error == GIT_ENOTFOUND)
 		giterr_clear();
 
+	if (error == GIT_EEXISTS) /* if contains .git, treat as untracked submod */
+		error = 0;
+
 	/* if submodule, mark as GITLINK and remove trailing slash */
 	if (!error) {
 		size_t len = strlen(wi->entry.path);
diff --git a/src/path.c b/src/path.c
index 5767faeed..6437979d5 100644
--- a/src/path.c
+++ b/src/path.c
@@ -877,15 +877,22 @@ int git_path_dirload_with_stat(
 		if (cmp_len && strncomp(ps->path, end_stat, cmp_len) > 0)
 			continue;
 
+		git_buf_truncate(&full, prefix_len);
+
 		if ((error = git_buf_joinpath(&full, full.ptr, ps->path)) < 0 ||
 			(error = git_path_lstat(full.ptr, &ps->st)) < 0)
 			break;
 
-		git_buf_truncate(&full, prefix_len);
-
 		if (S_ISDIR(ps->st.st_mode)) {
-			ps->path[ps->path_len++] = '/';
-			ps->path[ps->path_len] = '\0';
+			if ((error = git_buf_joinpath(&full, full.ptr, ".git")) < 0)
+				break;
+
+			if (p_access(full.ptr, F_OK) == 0) {
+				ps->st.st_mode = GIT_FILEMODE_COMMIT;
+			} else {
+				ps->path[ps->path_len++] = '/';
+				ps->path[ps->path_len] = '\0';
+			}
 		}
 	}