16 files changed, 126 insertions, 52 deletions

diff --git a/drivers/gles3/rasterizer_canvas_gles3.cpp b/drivers/gles3/rasterizer_canvas_gles3.cpp
index 2887b6b44f..89b1c1889e 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.cpp
+++ b/drivers/gles3/rasterizer_canvas_gles3.cpp
@@ -803,7 +803,7 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 
 				light_count++;
 
-				if (light_count == data.max_lights_per_item) {
+				if (light_count == data.max_lights_per_item - 1) {
 					break;
 				}
 			}
@@ -905,10 +905,12 @@ void RasterizerCanvasGLES3::_record_item_commands(const Item *p_item, RID p_rend
 
 					if (rect->flags & CANVAS_RECT_FLIP_H) {
 						src_rect.size.x *= -1;
+						state.instance_data_array[r_index].flags |= FLAGS_FLIP_H;
 					}
 
 					if (rect->flags & CANVAS_RECT_FLIP_V) {
 						src_rect.size.y *= -1;
+						state.instance_data_array[r_index].flags |= FLAGS_FLIP_V;
 					}
 
 					if (rect->flags & CANVAS_RECT_TRANSPOSE) {
@@ -2652,8 +2654,10 @@ RasterizerCanvasGLES3::RasterizerCanvasGLES3() {
 
 shader_type canvas_item;
 
+uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
+
 void fragment() {
-	vec4 c = textureLod(SCREEN_TEXTURE, SCREEN_UV, 0.0);
+	vec4 c = textureLod(screen_texture, SCREEN_UV, 0.0);
 
 	if (c.a > 0.0001) {
 		c.rgb /= c.a;
@@ -2677,8 +2681,10 @@ void fragment() {
 
 shader_type canvas_item;
 
+uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
+
 void fragment() {
-	vec4 c = textureLod(SCREEN_TEXTURE, SCREEN_UV, 0.0);
+	vec4 c = textureLod(screen_texture, SCREEN_UV, 0.0);
 	COLOR.rgb = c.rgb;
 }
 )");
diff --git a/drivers/gles3/rasterizer_canvas_gles3.h b/drivers/gles3/rasterizer_canvas_gles3.h
index db9203b249..916e12057c 100644
--- a/drivers/gles3/rasterizer_canvas_gles3.h
+++ b/drivers/gles3/rasterizer_canvas_gles3.h
@@ -75,6 +75,9 @@ class RasterizerCanvasGLES3 : public RendererCanvasRender {
 
 		FLAGS_USE_MSDF = (1 << 28),
 		FLAGS_USE_LCD = (1 << 29),
+
+		FLAGS_FLIP_H = (1 << 30),
+		FLAGS_FLIP_V = (1 << 31),
 	};
 
 	enum {
diff --git a/drivers/gles3/rasterizer_scene_gles3.cpp b/drivers/gles3/rasterizer_scene_gles3.cpp
index e4bcc424b3..9547435607 100644
--- a/drivers/gles3/rasterizer_scene_gles3.cpp
+++ b/drivers/gles3/rasterizer_scene_gles3.cpp
@@ -1535,8 +1535,6 @@ void RasterizerSceneGLES3::_setup_lights(const RenderDataGLES3 *p_render_data, b
 					}
 				}
 
-				li->gl_id = r_omni_light_count;
-
 				scene_state.omni_light_sort[r_omni_light_count].instance = li;
 				scene_state.omni_light_sort[r_omni_light_count].depth = distance;
 				r_omni_light_count++;
@@ -1560,8 +1558,6 @@ void RasterizerSceneGLES3::_setup_lights(const RenderDataGLES3 *p_render_data, b
 					}
 				}
 
-				li->gl_id = r_spot_light_count;
-
 				scene_state.spot_light_sort[r_spot_light_count].instance = li;
 				scene_state.spot_light_sort[r_spot_light_count].depth = distance;
 				r_spot_light_count++;
@@ -1584,8 +1580,11 @@ void RasterizerSceneGLES3::_setup_lights(const RenderDataGLES3 *p_render_data, b
 		LightData &light_data = (i < r_omni_light_count) ? scene_state.omni_lights[index] : scene_state.spot_lights[index];
 		RS::LightType type = (i < r_omni_light_count) ? RS::LIGHT_OMNI : RS::LIGHT_SPOT;
 		GLES3::LightInstance *li = (i < r_omni_light_count) ? scene_state.omni_light_sort[index].instance : scene_state.spot_light_sort[index].instance;
+		real_t distance = (i < r_omni_light_count) ? scene_state.omni_light_sort[index].depth : scene_state.spot_light_sort[index].depth;
 		RID base = li->light;
 
+		li->gl_id = index;
+
 		Transform3D light_transform = li->transform;
 		Vector3 pos = inverse_transform.xform(light_transform.origin);
 
@@ -1612,13 +1611,11 @@ void RasterizerSceneGLES3::_setup_lights(const RenderDataGLES3 *p_render_data, b
 		// Reuse fade begin, fade length and distance for shadow LOD determination later.
 		float fade_begin = 0.0;
 		float fade_length = 0.0;
-		real_t distance = 0.0;
 
 		float fade = 1.0;
 		if (light_storage->light_is_distance_fade_enabled(li->light)) {
 			fade_begin = light_storage->light_get_distance_fade_begin(li->light);
 			fade_length = light_storage->light_get_distance_fade_length(li->light);
-			distance = p_render_data->cam_transform.origin.distance_to(li->transform.origin);
 
 			if (distance > fade_begin) {
 				// Use `smoothstep()` to make opacity changes more gradual and less noticeable to the player.
diff --git a/drivers/gles3/shaders/canvas.glsl b/drivers/gles3/shaders/canvas.glsl
index 9a90f33674..1631c65385 100644
--- a/drivers/gles3/shaders/canvas.glsl
+++ b/drivers/gles3/shaders/canvas.glsl
@@ -277,7 +277,7 @@ flat in uvec4 varying_G;
 uniform sampler2D atlas_texture; //texunit:-2
 uniform sampler2D shadow_atlas_texture; //texunit:-3
 #endif // DISABLE_LIGHTING
-uniform sampler2D screen_texture; //texunit:-4
+uniform sampler2D color_buffer; //texunit:-4
 uniform sampler2D sdf_texture; //texunit:-5
 uniform sampler2D normal_texture; //texunit:-6
 uniform sampler2D specular_texture; //texunit:-7
@@ -579,6 +579,12 @@ void main() {
 
 	if (normal_used || (using_light && bool(read_draw_data_flags & FLAGS_DEFAULT_NORMAL_MAP_USED))) {
 		normal.xy = texture(normal_texture, uv).xy * vec2(2.0, -2.0) - vec2(1.0, -1.0);
+		if (bool(read_draw_data_flags & FLAGS_FLIP_H)) {
+			normal.x = -normal.x;
+		}
+		if (bool(read_draw_data_flags & FLAGS_FLIP_V)) {
+			normal.y = -normal.y;
+		}
 		normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
 		normal_used = true;
 	} else {
diff --git a/drivers/gles3/shaders/canvas_uniforms_inc.glsl b/drivers/gles3/shaders/canvas_uniforms_inc.glsl
index f65558f042..d53c0fcb26 100644
--- a/drivers/gles3/shaders/canvas_uniforms_inc.glsl
+++ b/drivers/gles3/shaders/canvas_uniforms_inc.glsl
@@ -27,6 +27,9 @@
 #define FLAGS_USE_MSDF uint(1 << 28)
 #define FLAGS_USE_LCD uint(1 << 29)
 
+#define FLAGS_FLIP_H uint(1 << 30)
+#define FLAGS_FLIP_V uint(1 << 31)
+
 layout(std140) uniform GlobalShaderUniformData { //ubo:1
 	vec4 global_shader_uniforms[MAX_GLOBAL_SHADER_UNIFORMS];
 };
diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index 1b922fa726..951155e287 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -564,10 +564,10 @@ uniform highp samplerCubeShadow positional_shadow; // texunit:-4
 
 #ifdef USE_MULTIVIEW
 uniform highp sampler2DArray depth_buffer; // texunit:-6
-uniform highp sampler2DArray screen_texture; // texunit:-5
+uniform highp sampler2DArray color_buffer; // texunit:-5
 #else
 uniform highp sampler2D depth_buffer; // texunit:-6
-uniform highp sampler2D screen_texture; // texunit:-5
+uniform highp sampler2D color_buffer; // texunit:-5
 #endif
 
 uniform highp mat4 world_transform;
diff --git a/drivers/gles3/storage/material_storage.cpp b/drivers/gles3/storage/material_storage.cpp
index e54fad1551..50e5c868d3 100644
--- a/drivers/gles3/storage/material_storage.cpp
+++ b/drivers/gles3/storage/material_storage.cpp
@@ -1515,7 +1515,6 @@ MaterialStorage::MaterialStorage() {
 		actions.renames["SPECULAR_SHININESS_TEXTURE"] = "specular_texture";
 		actions.renames["SPECULAR_SHININESS"] = "specular_shininess";
 		actions.renames["SCREEN_UV"] = "screen_uv";
-		actions.renames["SCREEN_TEXTURE"] = "screen_texture";
 		actions.renames["SCREEN_PIXEL_SIZE"] = "screen_pixel_size";
 		actions.renames["FRAGCOORD"] = "gl_FragCoord";
 		actions.renames["POINT_COORD"] = "gl_PointCoord";
@@ -1536,7 +1535,6 @@ MaterialStorage::MaterialStorage() {
 		actions.renames["screen_uv_to_sdf"] = "screen_uv_to_sdf";
 
 		actions.usage_defines["COLOR"] = "#define COLOR_USED\n";
-		actions.usage_defines["SCREEN_TEXTURE"] = "#define SCREEN_TEXTURE_USED\n";
 		actions.usage_defines["SCREEN_UV"] = "#define SCREEN_UV_USED\n";
 		actions.usage_defines["SCREEN_PIXEL_SIZE"] = "@SCREEN_UV";
 		actions.usage_defines["NORMAL"] = "#define NORMAL_USED\n";
@@ -1617,9 +1615,6 @@ MaterialStorage::MaterialStorage() {
 		actions.renames["POINT_COORD"] = "gl_PointCoord";
 		actions.renames["INSTANCE_CUSTOM"] = "instance_custom";
 		actions.renames["SCREEN_UV"] = "screen_uv";
-		//actions.renames["SCREEN_TEXTURE"] = "color_buffer"; //Not implemented in 3D yet.
-		//actions.renames["DEPTH_TEXTURE"] = "depth_buffer"; // Not implemented in 3D yet.
-		//actions.renames["NORMAL_ROUGHNESS_TEXTURE"] = "normal_roughness_buffer"; // Not implemented in 3D yet
 		actions.renames["DEPTH"] = "gl_FragDepth";
 		actions.renames["OUTPUT_IS_SRGB"] = "true";
 		actions.renames["FOG"] = "fog";
@@ -1684,7 +1679,6 @@ MaterialStorage::MaterialStorage() {
 		actions.usage_defines["SSS_STRENGTH"] = "#define ENABLE_SSS\n";
 		actions.usage_defines["SSS_TRANSMITTANCE_DEPTH"] = "#define ENABLE_TRANSMITTANCE\n";
 		actions.usage_defines["BACKLIGHT"] = "#define LIGHT_BACKLIGHT_USED\n";
-		actions.usage_defines["SCREEN_TEXTURE"] = "#define SCREEN_TEXTURE_USED\n";
 		actions.usage_defines["SCREEN_UV"] = "#define SCREEN_UV_USED\n";
 
 		actions.usage_defines["DIFFUSE_LIGHT"] = "#define USE_LIGHT_SHADER_CODE\n";
@@ -2765,6 +2759,14 @@ void MaterialStorage::material_free(RID p_rid) {
 	Material *material = material_owner.get_or_null(p_rid);
 	ERR_FAIL_COND(!material);
 
+	// Need to clear texture arrays to prevent spin locking of their RID's.
+	// This happens when the app is being closed.
+	for (KeyValue<StringName, Variant> &E : material->params) {
+		if (E.value.get_type() == Variant::ARRAY) {
+			Array(E.value).clear();
+		}
+	}
+
 	material_set_shader(p_rid, RID()); //clean up shader
 	material->dependency.deleted_notify(p_rid);
 
@@ -2952,7 +2954,6 @@ void CanvasShaderData::set_code(const String &p_code) {
 	actions.render_mode_values["blend_premul_alpha"] = Pair<int *, int>(&blend_modei, BLEND_MODE_PMALPHA);
 	actions.render_mode_values["blend_disabled"] = Pair<int *, int>(&blend_modei, BLEND_MODE_DISABLED);
 
-	actions.usage_flag_pointers["SCREEN_TEXTURE"] = &uses_screen_texture;
 	actions.usage_flag_pointers["texture_sdf"] = &uses_sdf;
 	actions.usage_flag_pointers["TIME"] = &uses_time;
 
@@ -2966,6 +2967,7 @@ void CanvasShaderData::set_code(const String &p_code) {
 
 	blend_mode = BlendMode(blend_modei);
 	uses_screen_texture_mipmaps = gen_code.uses_screen_texture_mipmaps;
+	uses_screen_texture = gen_code.uses_screen_texture;
 
 #if 0
 	print_line("**compiling shader:");
@@ -3301,9 +3303,6 @@ void SceneShaderData::set_code(const String &p_code) {
 	actions.usage_flag_pointers["SSS_STRENGTH"] = &uses_sss;
 	actions.usage_flag_pointers["SSS_TRANSMITTANCE_DEPTH"] = &uses_transmittance;
 
-	actions.usage_flag_pointers["SCREEN_TEXTURE"] = &uses_screen_texture;
-	actions.usage_flag_pointers["DEPTH_TEXTURE"] = &uses_depth_texture;
-	actions.usage_flag_pointers["NORMAL_TEXTURE"] = &uses_normal_texture;
 	actions.usage_flag_pointers["DISCARD"] = &uses_discard;
 	actions.usage_flag_pointers["TIME"] = &uses_time;
 	actions.usage_flag_pointers["ROUGHNESS"] = &uses_roughness;
@@ -3356,6 +3355,9 @@ void SceneShaderData::set_code(const String &p_code) {
 	vertex_input_mask |= uses_bones << 9;
 	vertex_input_mask |= uses_weights << 10;
 	uses_screen_texture_mipmaps = gen_code.uses_screen_texture_mipmaps;
+	uses_screen_texture = gen_code.uses_screen_texture;
+	uses_depth_texture = gen_code.uses_depth_texture;
+	uses_normal_texture = gen_code.uses_normal_roughness_texture;
 	uses_vertex_time = gen_code.uses_vertex_time;
 	uses_fragment_time = gen_code.uses_fragment_time;
 
diff --git a/drivers/gles3/storage/render_scene_buffers_gles3.cpp b/drivers/gles3/storage/render_scene_buffers_gles3.cpp
index 65c4ca6131..19bf57df94 100644
--- a/drivers/gles3/storage/render_scene_buffers_gles3.cpp
+++ b/drivers/gles3/storage/render_scene_buffers_gles3.cpp
@@ -37,13 +37,14 @@ RenderSceneBuffersGLES3::~RenderSceneBuffersGLES3() {
 	free_render_buffer_data();
 }
 
-void RenderSceneBuffersGLES3::configure(RID p_render_target, const Size2i p_internal_size, const Size2i p_target_size, float p_fsr_sharpness, float p_texture_mipmap_bias, RS::ViewportMSAA p_msaa, RenderingServer::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_taa, bool p_use_debanding, uint32_t p_view_count) {
+void RenderSceneBuffersGLES3::configure(RID p_render_target, const Size2i p_internal_size, const Size2i p_target_size, RS::ViewportScaling3DMode p_scaling_3d_mode, float p_fsr_sharpness, float p_texture_mipmap_bias, RS::ViewportMSAA p_msaa, RenderingServer::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_taa, bool p_use_debanding, uint32_t p_view_count) {
 	GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
 
 	//internal_size.x = p_internal_size.x; // ignore for now
 	//internal_size.y = p_internal_size.y;
 	width = p_target_size.x;
 	height = p_target_size.y;
+	//scaling_3d_mode = p_scaling_3d_mode
 	//fsr_sharpness = p_fsr_sharpness;
 	//texture_mipmap_bias = p_texture_mipmap_bias;
 	render_target = p_render_target;
diff --git a/drivers/gles3/storage/render_scene_buffers_gles3.h b/drivers/gles3/storage/render_scene_buffers_gles3.h
index 52a7737910..d07a0812f6 100644
--- a/drivers/gles3/storage/render_scene_buffers_gles3.h
+++ b/drivers/gles3/storage/render_scene_buffers_gles3.h
@@ -81,7 +81,7 @@ public:
 private:
 public:
 	virtual ~RenderSceneBuffersGLES3();
-	virtual void configure(RID p_render_target, const Size2i p_internal_size, const Size2i p_target_size, float p_fsr_sharpness, float p_texture_mipmap_bias, RS::ViewportMSAA p_msaa, RenderingServer::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_taa, bool p_use_debanding, uint32_t p_view_count) override;
+	virtual void configure(RID p_render_target, const Size2i p_internal_size, const Size2i p_target_size, RS::ViewportScaling3DMode p_scaling_3d_mode, float p_fsr_sharpness, float p_texture_mipmap_bias, RS::ViewportMSAA p_msaa, RenderingServer::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_taa, bool p_use_debanding, uint32_t p_view_count) override;
 
 	virtual void set_fsr_sharpness(float p_fsr_sharpness) override{};
 	virtual void set_texture_mipmap_bias(float p_texture_mipmap_bias) override{};
diff --git a/drivers/gles3/storage/texture_storage.cpp b/drivers/gles3/storage/texture_storage.cpp
index 489c328f64..12def52d50 100644
--- a/drivers/gles3/storage/texture_storage.cpp
+++ b/drivers/gles3/storage/texture_storage.cpp
@@ -567,23 +567,29 @@ Ref<Image> TextureStorage::_get_gl_image_and_format(const Ref<Image> &p_image, I
 			}
 		} break;
 		case Image::FORMAT_ETC2_RA_AS_RG: {
+#ifndef WEB_ENABLED
 			if (config->etc2_supported) {
 				r_gl_internal_format = _EXT_COMPRESSED_RGBA8_ETC2_EAC;
 				r_gl_format = GL_RGBA;
 				r_gl_type = GL_UNSIGNED_BYTE;
 				r_compressed = true;
-			} else {
+			} else
+#endif
+			{
 				need_decompress = true;
 			}
 			decompress_ra_to_rg = true;
 		} break;
 		case Image::FORMAT_DXT5_RA_AS_RG: {
+#ifndef WEB_ENABLED
 			if (config->s3tc_supported) {
 				r_gl_internal_format = _EXT_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 				r_gl_format = GL_RGBA;
 				r_gl_type = GL_UNSIGNED_BYTE;
 				r_compressed = true;
-			} else {
+			} else
+#endif
+			{
 				need_decompress = true;
 			}
 			decompress_ra_to_rg = true;
@@ -1137,6 +1143,7 @@ void TextureStorage::texture_set_data(RID p_texture, const Ref<Image> &p_image,
 	texture->gl_set_filter(RS::CANVAS_ITEM_TEXTURE_FILTER_NEAREST);
 	texture->gl_set_repeat(RS::CANVAS_ITEM_TEXTURE_REPEAT_ENABLED);
 
+#ifndef WEB_ENABLED
 	switch (texture->format) {
 #ifdef GLES_OVER_GL
 		case Image::FORMAT_L8: {
@@ -1151,7 +1158,8 @@ void TextureStorage::texture_set_data(RID p_texture, const Ref<Image> &p_image,
 			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_B, GL_RED);
 			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_GREEN);
 		} break;
-#endif
+#endif // GLES3_OVER_GL
+
 		case Image::FORMAT_ETC2_RA_AS_RG:
 		case Image::FORMAT_DXT5_RA_AS_RG: {
 			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_R, GL_RED);
@@ -1172,6 +1180,7 @@ void TextureStorage::texture_set_data(RID p_texture, const Ref<Image> &p_image,
 			glTexParameteri(texture->target, GL_TEXTURE_SWIZZLE_A, GL_ALPHA);
 		} break;
 	}
+#endif // WEB_ENABLED
 
 	int mipmaps = img->has_mipmaps() ? img->get_mipmap_count() + 1 : 1;
 
@@ -1525,18 +1534,6 @@ AABB TextureStorage::decal_get_aabb(RID p_decal) const {
 	return AABB();
 }
 
-/* DECAL INSTANCE API */
-
-RID TextureStorage::decal_instance_create(RID p_decal) {
-	return RID();
-}
-
-void TextureStorage::decal_instance_free(RID p_decal_instance) {
-}
-
-void TextureStorage::decal_instance_set_transform(RID p_decal, const Transform3D &p_transform) {
-}
-
 /* RENDER TARGET API */
 
 GLuint TextureStorage::system_fbo = 0;
diff --git a/drivers/gles3/storage/texture_storage.h b/drivers/gles3/storage/texture_storage.h
index 9ffe16fd16..9d3f407226 100644
--- a/drivers/gles3/storage/texture_storage.h
+++ b/drivers/gles3/storage/texture_storage.h
@@ -561,9 +561,10 @@ public:
 
 	/* DECAL INSTANCE */
 
-	virtual RID decal_instance_create(RID p_decal) override;
-	virtual void decal_instance_free(RID p_decal_instance) override;
-	virtual void decal_instance_set_transform(RID p_decal, const Transform3D &p_transform) override;
+	virtual RID decal_instance_create(RID p_decal) override { return RID(); }
+	virtual void decal_instance_free(RID p_decal_instance) override {}
+	virtual void decal_instance_set_transform(RID p_decal, const Transform3D &p_transform) override {}
+	virtual void decal_instance_set_sorting_offset(RID p_decal_instance, float p_sorting_offset) override {}
 
 	/* RENDER TARGET API */
 
diff --git a/drivers/unix/dir_access_unix.cpp b/drivers/unix/dir_access_unix.cpp
index 557060c907..a162f46103 100644
--- a/drivers/unix/dir_access_unix.cpp
+++ b/drivers/unix/dir_access_unix.cpp
@@ -189,7 +189,7 @@ void DirAccessUnix::list_dir_end() {
 	_cisdir = false;
 }
 
-#if defined(HAVE_MNTENT) && defined(X11_ENABLED)
+#if defined(HAVE_MNTENT) && defined(LINUXBSD_ENABLED)
 static bool _filter_drive(struct mntent *mnt) {
 	// Ignore devices that don't point to /dev
 	if (strncmp(mnt->mnt_fsname, "/dev", 4) != 0) {
@@ -213,7 +213,7 @@ static void _get_drives(List<String> *list) {
 	// Add root.
 	list->push_back("/");
 
-#if defined(HAVE_MNTENT) && defined(X11_ENABLED)
+#if defined(HAVE_MNTENT) && defined(LINUXBSD_ENABLED)
 	// Check /etc/mtab for the list of mounted partitions.
 	FILE *mtab = setmntent("/etc/mtab", "r");
 	if (mtab) {
diff --git a/drivers/unix/os_unix.cpp b/drivers/unix/os_unix.cpp
index c37b3d9c87..178f01b185 100644
--- a/drivers/unix/os_unix.cpp
+++ b/drivers/unix/os_unix.cpp
@@ -411,10 +411,6 @@ bool OS_Unix::is_process_running(const ProcessID &p_pid) const {
 	return true;
 }
 
-bool OS_Unix::has_environment(const String &p_var) const {
-	return getenv(p_var.utf8().get_data()) != nullptr;
-}
-
 String OS_Unix::get_locale() const {
 	if (!has_environment("LANG")) {
 		return "en";
@@ -487,6 +483,10 @@ Error OS_Unix::set_cwd(const String &p_cwd) {
 	return OK;
 }
 
+bool OS_Unix::has_environment(const String &p_var) const {
+	return getenv(p_var.utf8().get_data()) != nullptr;
+}
+
 String OS_Unix::get_environment(const String &p_var) const {
 	if (getenv(p_var.utf8().get_data())) {
 		return getenv(p_var.utf8().get_data());
@@ -494,8 +494,15 @@ String OS_Unix::get_environment(const String &p_var) const {
 	return "";
 }
 
-bool OS_Unix::set_environment(const String &p_var, const String &p_value) const {
-	return setenv(p_var.utf8().get_data(), p_value.utf8().get_data(), /* overwrite: */ true) == 0;
+void OS_Unix::set_environment(const String &p_var, const String &p_value) const {
+	ERR_FAIL_COND_MSG(p_var.is_empty() || p_var.contains("="), vformat("Invalid environment variable name '%s', cannot be empty or include '='.", p_var));
+	int err = setenv(p_var.utf8().get_data(), p_value.utf8().get_data(), /* overwrite: */ 1);
+	ERR_FAIL_COND_MSG(err != 0, vformat("Failed setting environment variable '%s', the system is out of memory.", p_var));
+}
+
+void OS_Unix::unset_environment(const String &p_var) const {
+	ERR_FAIL_COND_MSG(p_var.is_empty() || p_var.contains("="), vformat("Invalid environment variable name '%s', cannot be empty or include '='.", p_var));
+	unsetenv(p_var.utf8().get_data());
 }
 
 String OS_Unix::get_user_data_dir() const {
diff --git a/drivers/unix/os_unix.h b/drivers/unix/os_unix.h
index 416311307c..03429622ae 100644
--- a/drivers/unix/os_unix.h
+++ b/drivers/unix/os_unix.h
@@ -81,7 +81,9 @@ public:
 
 	virtual bool has_environment(const String &p_var) const override;
 	virtual String get_environment(const String &p_var) const override;
-	virtual bool set_environment(const String &p_var, const String &p_value) const override;
+	virtual void set_environment(const String &p_var, const String &p_value) const override;
+	virtual void unset_environment(const String &p_var) const override;
+
 	virtual String get_locale() const override;
 
 	virtual void initialize_debugging() override;
diff --git a/drivers/windows/file_access_windows.cpp b/drivers/windows/file_access_windows.cpp
index 37a94ce4cc..ea40622afc 100644
--- a/drivers/windows/file_access_windows.cpp
+++ b/drivers/windows/file_access_windows.cpp
@@ -34,7 +34,6 @@
 
 #include "core/os/os.h"
 #include "core/string/print_string.h"
-
 #include <share.h> // _SH_DENYNO
 #include <shlwapi.h>
 #define WIN32_LEAN_AND_MEAN
@@ -58,7 +57,27 @@ void FileAccessWindows::check_errors() const {
 	}
 }
 
+bool FileAccessWindows::is_path_invalid(const String &p_path) {
+	// Check for invalid operating system file.
+	String fname = p_path;
+	int dot = fname.find(".");
+	if (dot != -1) {
+		fname = fname.substr(0, dot);
+	}
+	fname = fname.to_lower();
+	return invalid_files.has(fname);
+}
+
 Error FileAccessWindows::open_internal(const String &p_path, int p_mode_flags) {
+	if (is_path_invalid(p_path)) {
+#ifdef DEBUG_ENABLED
+		if (p_mode_flags != READ) {
+			WARN_PRINT("The path :" + p_path + " is a reserved Windows system pipe, so it can't be used for creating files.");
+		}
+#endif
+		return ERR_INVALID_PARAMETER;
+	}
+
 	_close();
 
 	path_src = p_path;
@@ -313,6 +332,10 @@ void FileAccessWindows::store_buffer(const uint8_t *p_src, uint64_t p_length) {
 }
 
 bool FileAccessWindows::file_exists(const String &p_name) {
+	if (is_path_invalid(p_name)) {
+		return false;
+	}
+
 	String filename = fix_path(p_name);
 	FILE *g = _wfsopen((LPCWSTR)(filename.utf16().get_data()), L"rb", _SH_DENYNO);
 	if (g == nullptr) {
@@ -324,6 +347,10 @@ bool FileAccessWindows::file_exists(const String &p_name) {
 }
 
 uint64_t FileAccessWindows::_get_modified_time(const String &p_file) {
+	if (is_path_invalid(p_file)) {
+		return 0;
+	}
+
 	String file = fix_path(p_file);
 	if (file.ends_with("/") && file != "/") {
 		file = file.substr(0, file.length() - 1);
@@ -352,4 +379,20 @@ FileAccessWindows::~FileAccessWindows() {
 	_close();
 }
 
+HashSet<String> FileAccessWindows::invalid_files;
+
+void FileAccessWindows::initialize() {
+	static const char *reserved_files[]{
+		"con", "prn", "aux", "nul", "com0", "com1", "com2", "com3", "com4", "com5", "com6", "com7", "com8", "com9", "lpt0", "lpt1", "lpt2", "lpt3", "lpt4", "lpt5", "lpt6", "lpt7", "lpt8", "lpt9", nullptr
+	};
+	int reserved_file_index = 0;
+	while (reserved_files[reserved_file_index] != nullptr) {
+		invalid_files.insert(reserved_files[reserved_file_index]);
+		reserved_file_index++;
+	}
+}
+void FileAccessWindows::finalize() {
+	invalid_files.clear();
+}
+
 #endif // WINDOWS_ENABLED
diff --git a/drivers/windows/file_access_windows.h b/drivers/windows/file_access_windows.h
index 832cef3363..2b9960d494 100644
--- a/drivers/windows/file_access_windows.h
+++ b/drivers/windows/file_access_windows.h
@@ -50,6 +50,9 @@ class FileAccessWindows : public FileAccess {
 
 	void _close();
 
+	static bool is_path_invalid(const String &p_path);
+	static HashSet<String> invalid_files;
+
 public:
 	virtual Error open_internal(const String &p_path, int p_mode_flags) override; ///< open a file
 	virtual bool is_open() const override; ///< true when file is open
@@ -79,6 +82,9 @@ public:
 	virtual uint32_t _get_unix_permissions(const String &p_file) override;
 	virtual Error _set_unix_permissions(const String &p_file, uint32_t p_permissions) override;
 
+	static void initialize();
+	static void finalize();
+
 	FileAccessWindows() {}
 	virtual ~FileAccessWindows();
 };