Don't return reference on copy assignment operators

We prefer to prevent using chained assignment (`T a = b = c = T();`) as this
can lead to confusing code and subtle bugs.

According to https://en.wikipedia.org/wiki/Assignment_operator_(C%2B%2B), C++
allows any arbitrary return type, so this is standard compliant.

This could be re-assessed if/when we have an actual need for a behavior more
akin to that of the C++ STL, for now this PR simply changes a handful of
cases which were inconsistent with the rest of the codebase (`void` return
type was already the most common case prior to this commit).

3 files changed, 13 insertions, 12 deletions

diff --git a/scene/3d/soft_dynamic_body_3d.cpp b/scene/3d/soft_dynamic_body_3d.cpp
index 5546b88fb1..d9907430fc 100644
--- a/scene/3d/soft_dynamic_body_3d.cpp
+++ b/scene/3d/soft_dynamic_body_3d.cpp
@@ -100,12 +100,11 @@ SoftDynamicBody3D::PinnedPoint::PinnedPoint(const PinnedPoint &obj_tocopy) {
 	offset = obj_tocopy.offset;
 }
 
-SoftDynamicBody3D::PinnedPoint &SoftDynamicBody3D::PinnedPoint::operator=(const PinnedPoint &obj) {
+void SoftDynamicBody3D::PinnedPoint::operator=(const PinnedPoint &obj) {
 	point_index = obj.point_index;
 	spatial_attachment_path = obj.spatial_attachment_path;
 	spatial_attachment = obj.spatial_attachment;
 	offset = obj.offset;
-	return *this;
 }
 
 void SoftDynamicBody3D::_update_pickable() {
diff --git a/scene/3d/soft_dynamic_body_3d.h b/scene/3d/soft_dynamic_body_3d.h
index 57e116aa05..daef9acac0 100644
--- a/scene/3d/soft_dynamic_body_3d.h
+++ b/scene/3d/soft_dynamic_body_3d.h
@@ -80,7 +80,7 @@ public:
 
 		PinnedPoint();
 		PinnedPoint(const PinnedPoint &obj_tocopy);
-		PinnedPoint &operator=(const PinnedPoint &obj);
+		void operator=(const PinnedPoint &obj);
 	};
 
 private:
diff --git a/scene/gui/file_dialog.cpp b/scene/gui/file_dialog.cpp
index 44853fc006..e3754c4d38 100644
--- a/scene/gui/file_dialog.cpp
+++ b/scene/gui/file_dialog.cpp
@@ -473,6 +473,13 @@ void FileDialog::update_file_list() {
 
 	dir_access->list_dir_begin();
 
+	if (dir_access->is_readable(dir_access->get_current_dir().utf8().get_data())) {
+		message->hide();
+	} else {
+		message->set_text(TTRC("You don't have permission to access contents of this folder."));
+		message->show();
+	}
+
 	TreeItem *root = tree->create_item();
 	Ref<Texture2D> folder = vbox->get_theme_icon(SNAME("folder"), SNAME("FileDialog"));
 	Ref<Texture2D> file_icon = vbox->get_theme_icon(SNAME("file"), SNAME("FileDialog"));
@@ -482,17 +489,11 @@ void FileDialog::update_file_list() {
 	List<String> dirs;
 
 	bool is_hidden;
-	String item;
-
-	if (dir_access->is_readable(dir_access->get_current_dir().utf8().get_data())) {
-		message->hide();
-	} else {
-		message->set_text(TTRC("You don't have permission to access contents of this folder."));
-		message->show();
-	}
+	String item = dir_access->get_next();
 
-	while ((item = dir_access->get_next()) != "") {
+	while (!item.is_empty()) {
 		if (item == "." || item == "..") {
+			item = dir_access->get_next();
 			continue;
 		}
 
@@ -505,6 +506,7 @@ void FileDialog::update_file_list() {
 				dirs.push_back(item);
 			}
 		}
+		item = dir_access->get_next();
 	}
 
 	dirs.sort_custom<NaturalNoCaseComparator>();