Fix many errors found by PVS-Studio

Fix errors 2, 3, 4, 6, 8, 9, 11, 12, 13, 14, and 15.

core/variant_op.cpp

@@ -2149,7 +2149,7 @@ void Variant::set(const Variant &p_index, const Variant &p_value, bool *r_valid)
 				int idx = p_index;
 				if (idx < 0)
 					idx += 4;
-				if (idx >= 0 || idx < 4) {
+				if (idx >= 0 && idx < 4) {
 					Color *v = reinterpret_cast<Color *>(_data._mem);
 					(*v)[idx] = p_value;
 					valid = true;
@@ -2524,7 +2524,7 @@ Variant Variant::get(const Variant &p_index, bool *r_valid) const {
 				int idx = p_index;
 				if (idx < 0)
 					idx += 4;
-				if (idx >= 0 || idx < 4) {
+				if (idx >= 0 && idx < 4) {
 					const Color *v = reinterpret_cast<const Color *>(_data._mem);
 					valid = true;
 					return (*v)[idx];

drivers/gles2/shader_gles2.cpp

@@ -99,7 +99,7 @@ void ShaderGLES2::bind_uniforms() {
 	const Map<uint32_t, CameraMatrix>::Element *C = uniform_cameras.front();
 
 	while (C) {
-		int idx = E->key();
+		int idx = C->key();
 		int location = version->uniform_location[idx];
 
 		if (location < 0) {

editor/editor_spin_slider.cpp

@@ -154,7 +154,7 @@ void EditorSpinSlider::_grabber_gui_input(const Ref<InputEvent> &p_event) {
 
 void EditorSpinSlider::_notification(int p_what) {
 
-	if (p_what == MainLoop::NOTIFICATION_WM_FOCUS_OUT || p_what == MainLoop::NOTIFICATION_WM_FOCUS_OUT) {
+	if (p_what == MainLoop::NOTIFICATION_WM_FOCUS_OUT || p_what == MainLoop::NOTIFICATION_WM_FOCUS_IN) {
 		if (grabbing_spinner) {
 			Input::get_singleton()->set_mouse_mode(Input::MOUSE_MODE_VISIBLE);
 			grabbing_spinner = false;

editor/plugins/animation_state_machine_editor.cpp

@@ -849,7 +849,7 @@ void AnimationNodeStateMachineEditor::_state_machine_pos_draw() {
 		return;
 
 	int idx = -1;
-	for (int i = 0; node_rects.size(); i++) {
+	for (int i = 0; i < node_rects.size(); i++) {
 		if (node_rects[i].node_name == playback->get_current_node()) {
 			idx = i;
 			break;

editor/plugins/sprite_frames_editor_plugin.cpp

@@ -598,7 +598,7 @@ bool SpriteFramesEditor::can_drop_data_fw(const Point2 &p_point, const Variant &
 			return false;
 
 		for (int i = 0; i < files.size(); i++) {
-			String file = files[0];
+			String file = files[i];
 			String ftype = EditorFileSystem::get_singleton()->get_file_type(file);
 
 			if (!ClassDB::is_parent_class(ftype, "Texture")) {

main/tests/test_shader_lang.cpp

@@ -180,7 +180,7 @@ static String dump_node_code(SL::Node *p_node, int p_level) {
 
 				String scode = dump_node_code(bnode->statements[i], p_level);
 
-				if (bnode->statements[i]->type == SL::Node::TYPE_CONTROL_FLOW || bnode->statements[i]->type == SL::Node::TYPE_CONTROL_FLOW) {
+				if (bnode->statements[i]->type == SL::Node::TYPE_CONTROL_FLOW) {
 					code += scode; //use directly
 				} else {
 					code += _mktab(p_level) + scode + ";\n";

modules/gdscript/gdscript_compiler.cpp

@@ -132,7 +132,7 @@ GDScriptDataType GDScriptCompiler::_gdtype_from_datatype(const GDScriptParser::D
 			result.kind = GDScriptDataType::SCRIPT;
 			result.script_type = p_datatype.script_type;
 			result.native_type = result.script_type->get_instance_base_type();
-		}
+		} break;
 		case GDScriptParser::DataType::GDSCRIPT: {
 			result.kind = GDScriptDataType::GDSCRIPT;
 			result.script_type = p_datatype.script_type;

scene/3d/cpu_particles.cpp

@@ -691,7 +691,7 @@ void CPUParticles::_particles_process(float p_delta) {
 
 			if (flags[FLAG_DISABLE_Z]) {
 				p.velocity.z = 0.0;
-				p.velocity.z = 0.0;
+				p.transform.origin.z = 0.0;
 			}
 
 		} else if (!p.active) {
@@ -757,15 +757,15 @@ void CPUParticles::_particles_process(float p_delta) {
 			}
 
 			Vector3 force = gravity;
-			Vector3 pos = p.transform.origin;
+			Vector3 position = p.transform.origin;
 			if (flags[FLAG_DISABLE_Z]) {
-				pos.z = 0.0;
+				position.z = 0.0;
 			}
 			//apply linear acceleration
 			force += p.velocity.length() > 0.0 ? p.velocity.normalized() * (parameters[PARAM_LINEAR_ACCEL] + tex_linear_accel) * Math::lerp(1.0f, rand_from_seed(alt_seed), randomness[PARAM_LINEAR_ACCEL]) : Vector3();
 			//apply radial acceleration
 			Vector3 org = emission_xform.origin;
-			Vector3 diff = pos - org;
+			Vector3 diff = position - org;
 			force += diff.length() > 0.0 ? diff.normalized() * (parameters[PARAM_RADIAL_ACCEL] + tex_radial_accel) * Math::lerp(1.0f, rand_from_seed(alt_seed), randomness[PARAM_RADIAL_ACCEL]) : Vector3();
 			//apply tangential acceleration;
 			if (flags[FLAG_DISABLE_Z]) {

scene/3d/soft_body.cpp

@@ -401,7 +401,7 @@ String SoftBody::get_configuration_warning() const {
 	}
 
 	Transform t = get_transform();
-	if ((ABS(t.basis.get_axis(0).length() - 1.0) > 0.05 || ABS(t.basis.get_axis(1).length() - 1.0) > 0.05 || ABS(t.basis.get_axis(0).length() - 1.0) > 0.05)) {
+	if ((ABS(t.basis.get_axis(0).length() - 1.0) > 0.05 || ABS(t.basis.get_axis(1).length() - 1.0) > 0.05 || ABS(t.basis.get_axis(2).length() - 1.0) > 0.05)) {
 		if (!warning.empty())
 			warning += "\n\n";
 

scene/resources/texture.cpp

@@ -994,11 +994,11 @@ void AtlasTexture::_bind_methods() {
 
 void AtlasTexture::draw(RID p_canvas_item, const Point2 &p_pos, const Color &p_modulate, bool p_transpose, const Ref<Texture> &p_normal_map) const {
 
-	Rect2 rc = region;
-
 	if (!atlas.is_valid())
 		return;
 
+	Rect2 rc = region;
+
 	if (rc.size.width == 0) {
 		rc.size.width = atlas->get_width();
 	}
@@ -1013,11 +1013,11 @@ void AtlasTexture::draw(RID p_canvas_item, const Point2 &p_pos, const Color &p_m
 
 void AtlasTexture::draw_rect(RID p_canvas_item, const Rect2 &p_rect, bool p_tile, const Color &p_modulate, bool p_transpose, const Ref<Texture> &p_normal_map) const {
 
-	Rect2 rc = region;
-
 	if (!atlas.is_valid())
 		return;
 
+	Rect2 rc = region;
+
 	if (rc.size.width == 0) {
 		rc.size.width = atlas->get_width();
 	}
@@ -1048,11 +1048,11 @@ void AtlasTexture::draw_rect_region(RID p_canvas_item, const Rect2 &p_rect, cons
 
 bool AtlasTexture::get_rect_region(const Rect2 &p_rect, const Rect2 &p_src_rect, Rect2 &r_rect, Rect2 &r_src_rect) const {
 
-	Rect2 rc = region;
-
 	if (!atlas.is_valid())
 		return false;
 
+	Rect2 rc = region;
+
 	Rect2 src = p_src_rect;
 	if (src.size == Size2()) {
 		src.size = rc.size;
@@ -1084,11 +1084,13 @@ bool AtlasTexture::get_rect_region(const Rect2 &p_rect, const Rect2 &p_src_rect,
 
 bool AtlasTexture::is_pixel_opaque(int p_x, int p_y) const {
 
-	if (atlas.is_valid()) {
+	if (!atlas.is_valid())
-		return atlas->is_pixel_opaque(p_x + region.position.x + margin.position.x, p_x + region.position.y + margin.position.y);
-	}
-
 		return true;
+
+	int x = p_x + region.position.x + margin.position.x;
+	int y = p_y + region.position.y + margin.position.y;
+
+	return atlas->is_pixel_opaque(x, y);
 }
 
 AtlasTexture::AtlasTexture() {