Fixes logically dead code (Coverity)

Fixes reported logically dead codes by Coverity

* image.cpp: Doesn't really need any modification. But to remove the bug
report then we have to move the MAX call away from the for loop
statement.

* rasterizer_gles3.cpp: Removes unnecessary elif condition since it is
checked earlier in the function

* collada.cpp: If stamement never reached due to macro ERR_CONTINUE does
the same.

* navigation_mesh.cpp: Variables should always be null - however, also
checked for the very same condition in their function call. Leaving this
for review (whether the function call is necessary or not)

* path_editor_plugin.cpp: If cancel is true, then it should restore the
edited value to the original provided.
http://docs.godotengine.org/en/3.0/classes/class_editorspatialgizmo.html#class-editorspatialgizmo-commit-handle

* spatial_editor_gizmos.cpp: the very condition of i >= 3 is
predetermined in the if case right before it. Thus case 1 is always '1'
and case 2 is always '-1'

* grid_map_editor.cpp: Same as above in spatial_editor_gizmos.cpp

* voxel_light_baker.cpp: Same as above in spatial_editor_gizmos.cpp

* visual_server.cpp: Same as above in spatial_editor_gizmos.cpp

* visual_script_expression.cpp: char '-' is already true in the switch
case mechanism. Thus it can never reach to default case.

* particles.cpp: Case 'PARAM_MAX' is unreachable due to index checking
right before the switch execution.

* shader_language.cpp: Invalid index is handled in switch default case.
`type < TYPE_FLOAT && type > TYPE_VEC4` -> `(type < TYPE_FLOAT || type > TYPE_VEC4`)
Fixes the "always false problem" in TODO comment.

13 files changed, 38 insertions, 65 deletions

diff --git a/core/image.cpp b/core/image.cpp
index 2ac8ffea56..9f03892e74 100644
--- a/core/image.cpp
+++ b/core/image.cpp
@@ -366,6 +366,8 @@ int Image::get_mipmap_count() const {
 template <uint32_t read_bytes, bool read_alpha, uint32_t write_bytes, bool write_alpha, bool read_gray, bool write_gray>
 static void _convert(int p_width, int p_height, const uint8_t *p_src, uint8_t *p_dst) {
 
+	uint32_t max_bytes = MAX(read_bytes, write_bytes);
+
 	for (int y = 0; y < p_height; y++) {
 		for (int x = 0; x < p_width; x++) {
 
@@ -379,7 +381,8 @@ static void _convert(int p_width, int p_height, const uint8_t *p_src, uint8_t *p
 				rgba[1] = rofs[0];
 				rgba[2] = rofs[0];
 			} else {
-				for (uint32_t i = 0; i < MAX(read_bytes, write_bytes); i++) {
+
+				for (uint32_t i = 0; i < max_bytes; i++) {
 
 					rgba[i] = (i < read_bytes) ? rofs[i] : 0;
 				}
diff --git a/core/node_path.cpp b/core/node_path.cpp
index cd7ad77534..64983fc091 100644
--- a/core/node_path.cpp
+++ b/core/node_path.cpp
@@ -264,8 +264,9 @@ NodePath NodePath::get_as_property_path() const {
 		Vector<StringName> new_path = data->subpath;
 
 		String initial_subname = data->path[0];
+
 		for (size_t i = 1; i < data->path.size(); i++) {
-			initial_subname += i == 0 ? data->path[i].operator String() : "/" + data->path[i];
+			initial_subname += "/" + data->path[i];
 		}
 		new_path.insert(0, initial_subname);
 
diff --git a/drivers/gles3/rasterizer_gles3.cpp b/drivers/gles3/rasterizer_gles3.cpp
index ca39d9f966..0fb69494f4 100644
--- a/drivers/gles3/rasterizer_gles3.cpp
+++ b/drivers/gles3/rasterizer_gles3.cpp
@@ -111,8 +111,6 @@ static void GLAPIENTRY _gl_debug_print(GLenum source, GLenum type, GLuint id, GL
 		strcpy(debType, "Portability");
 	else if (type == _EXT_DEBUG_TYPE_PERFORMANCE_ARB)
 		strcpy(debType, "Performance");
-	else if (type == _EXT_DEBUG_TYPE_OTHER_ARB)
-		strcpy(debType, "Other");
 
 	if (severity == _EXT_DEBUG_SEVERITY_HIGH_ARB)
 		strcpy(debSev, "High");
diff --git a/editor/collada/collada.cpp b/editor/collada/collada.cpp
index 4ce57d7f63..734229d014 100644
--- a/editor/collada/collada.cpp
+++ b/editor/collada/collada.cpp
@@ -2266,10 +2266,8 @@ void Collada::_merge_skeletons2(VisualScene *p_vscene) {
 				}
 				node = node->parent;
 			}
-			ERR_CONTINUE(!sk);
 
-			if (!sk)
-				continue; //bleh
+			ERR_CONTINUE(!sk);
 
 			if (!skeleton) {
 				skeleton = sk;
diff --git a/editor/plugins/navigation_mesh_generator.cpp b/editor/plugins/navigation_mesh_generator.cpp
index 5d4e5520f4..0537c5c31f 100644
--- a/editor/plugins/navigation_mesh_generator.cpp
+++ b/editor/plugins/navigation_mesh_generator.cpp
@@ -280,26 +280,20 @@ void NavigationMeshGenerator::bake(Ref<NavigationMesh> p_nav_mesh, Node *p_node)
 
 		_build_recast_navigation_mesh(p_nav_mesh, &ep, hf, chf, cset, poly_mesh, detail_mesh, vertices, indices);
 
-		if (hf) {
-			rcFreeHeightField(hf);
-			hf = 0;
-		}
-		if (chf) {
-			rcFreeCompactHeightfield(chf);
-			chf = 0;
-		}
-		if (cset) {
-			rcFreeContourSet(cset);
-			cset = 0;
-		}
-		if (poly_mesh) {
-			rcFreePolyMesh(poly_mesh);
-			poly_mesh = 0;
-		}
-		if (detail_mesh) {
-			rcFreePolyMeshDetail(detail_mesh);
-			detail_mesh = 0;
-		}
+		rcFreeHeightField(hf);
+		hf = 0;
+
+		rcFreeCompactHeightfield(chf);
+		chf = 0;
+
+		rcFreeContourSet(cset);
+		cset = 0;
+
+		rcFreePolyMesh(poly_mesh);
+		poly_mesh = 0;
+
+		rcFreePolyMeshDetail(detail_mesh);
+		detail_mesh = 0;
 	}
 	ep.step(TTR("Done!"), 11);
 }
diff --git a/editor/plugins/path_editor_plugin.cpp b/editor/plugins/path_editor_plugin.cpp
index 056219a575..6dde639c54 100644
--- a/editor/plugins/path_editor_plugin.cpp
+++ b/editor/plugins/path_editor_plugin.cpp
@@ -167,18 +167,12 @@ void PathSpatialGizmo::commit_handle(int p_idx, const Variant &p_restore, bool p
 
 	Vector3 ofs;
 
-	if (p_cancel) {
-
-		return;
-	}
-
 	if (t == 0) {
-
 		if (p_cancel) {
-
 			c->set_point_in(p_idx, p_restore);
 			return;
 		}
+
 		ur->create_action(TTR("Set Curve In Position"));
 		ur->add_do_method(c.ptr(), "set_point_in", idx, c->get_point_in(idx));
 		ur->add_undo_method(c.ptr(), "set_point_in", idx, p_restore);
@@ -186,10 +180,11 @@ void PathSpatialGizmo::commit_handle(int p_idx, const Variant &p_restore, bool p
 
 	} else {
 		if (p_cancel) {
-
 			c->set_point_out(idx, p_restore);
+
 			return;
 		}
+
 		ur->create_action(TTR("Set Curve Out Position"));
 		ur->add_do_method(c.ptr(), "set_point_out", idx, c->get_point_out(idx));
 		ur->add_undo_method(c.ptr(), "set_point_out", idx, p_restore);
diff --git a/editor/spatial_editor_gizmos.cpp b/editor/spatial_editor_gizmos.cpp
index 8c90d86b9e..a3c4b73ae4 100644
--- a/editor/spatial_editor_gizmos.cpp
+++ b/editor/spatial_editor_gizmos.cpp
@@ -4052,9 +4052,9 @@ SpatialEditorGizmos::SpatialEditorGizmos() {
 				for (int k = 0; k < 3; k++) {
 
 					if (i < 3)
-						face_points[j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[j][(i + k) % 3] = v[k];
 					else
-						face_points[3 - j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[3 - j][(i + k) % 3] = -v[k];
 				}
 			}
 			//tri 1
diff --git a/modules/gridmap/grid_map_editor_plugin.cpp b/modules/gridmap/grid_map_editor_plugin.cpp
index f523eef895..4b96824dca 100644
--- a/modules/gridmap/grid_map_editor_plugin.cpp
+++ b/modules/gridmap/grid_map_editor_plugin.cpp
@@ -1154,9 +1154,9 @@ GridMapEditor::GridMapEditor(EditorNode *p_editor) {
 				for (int k = 0; k < 3; k++) {
 
 					if (i < 3)
-						face_points[j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[j][(i + k) % 3] = v[k];
 					else
-						face_points[3 - j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[3 - j][(i + k) % 3] = -v[k];
 				}
 			}
 
diff --git a/modules/visual_script/visual_script_expression.cpp b/modules/visual_script/visual_script_expression.cpp
index 16de04e4cf..bf06e7af7f 100644
--- a/modules/visual_script/visual_script_expression.cpp
+++ b/modules/visual_script/visual_script_expression.cpp
@@ -455,7 +455,7 @@ Error VisualScriptExpression::_get_token(Token &r_token) {
 					break;
 				}
 
-				if (cchar == '-' || (cchar >= '0' && cchar <= '9')) {
+				if (cchar >= '0' && cchar <= '9') {
 					//a number
 
 					String num;
@@ -466,11 +466,6 @@ Error VisualScriptExpression::_get_token(Token &r_token) {
 #define READING_DONE 4
 					int reading = READING_INT;
 
-					if (cchar == '-') {
-						num += '-';
-						cchar = GET_CHAR();
-					}
-
 					CharType c = cchar;
 					bool exp_sign = false;
 					bool exp_beg = false;
diff --git a/scene/3d/particles.cpp b/scene/3d/particles.cpp
index 693b416f6d..d1bd059b63 100644
--- a/scene/3d/particles.cpp
+++ b/scene/3d/particles.cpp
@@ -1028,8 +1028,6 @@ void ParticlesMaterial::set_param(Parameter p_param, float p_value) {
 		case PARAM_ANIM_OFFSET: {
 			VisualServer::get_singleton()->material_set_param(_get_material(), shader_names->anim_offset, p_value);
 		} break;
-		case PARAM_MAX: {
-		};
 	}
 }
 float ParticlesMaterial::get_param(Parameter p_param) const {
@@ -1082,8 +1080,6 @@ void ParticlesMaterial::set_param_randomness(Parameter p_param, float p_value) {
 		case PARAM_ANIM_OFFSET: {
 			VisualServer::get_singleton()->material_set_param(_get_material(), shader_names->anim_offset_random, p_value);
 		} break;
-		case PARAM_MAX: {
-		};
 	}
 }
 float ParticlesMaterial::get_param_randomness(Parameter p_param) const {
@@ -1160,8 +1156,6 @@ void ParticlesMaterial::set_param_texture(Parameter p_param, const Ref<Texture>
 		case PARAM_ANIM_OFFSET: {
 			VisualServer::get_singleton()->material_set_param(_get_material(), shader_names->anim_offset_texture, p_texture);
 		} break;
-		case PARAM_MAX: {
-		};
 	}
 
 	_queue_shader_change();
diff --git a/scene/3d/voxel_light_baker.cpp b/scene/3d/voxel_light_baker.cpp
index d389b69ef3..13700e0bd3 100644
--- a/scene/3d/voxel_light_baker.cpp
+++ b/scene/3d/voxel_light_baker.cpp
@@ -2338,9 +2338,9 @@ Ref<MultiMesh> VoxelLightBaker::create_debug_multimesh(DebugMode p_mode) {
 				for (int k = 0; k < 3; k++) {
 
 					if (i < 3)
-						face_points[j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[j][(i + k) % 3] = v[k];
 					else
-						face_points[3 - j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+						face_points[3 - j][(i + k) % 3] = -v[k];
 				}
 			}
 
diff --git a/servers/visual/shader_language.cpp b/servers/visual/shader_language.cpp
index 7aca497881..01cf689a09 100644
--- a/servers/visual/shader_language.cpp
+++ b/servers/visual/shader_language.cpp
@@ -2677,7 +2677,6 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 					return NULL;
 				}
 
-				bool index_valid = false;
 				DataType member_type = TYPE_VOID;
 
 				switch (expr->get_datatype()) {
@@ -2696,7 +2695,7 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 							_set_error("Only integer constants are allowed as index at the moment");
 							return NULL;
 						}
-						index_valid = true;
+
 						switch (expr->get_datatype()) {
 							case TYPE_BVEC2: member_type = TYPE_BOOL; break;
 							case TYPE_VEC2: member_type = TYPE_FLOAT; break;
@@ -2721,7 +2720,7 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 							_set_error("Only integer constants are allowed as index at the moment");
 							return NULL;
 						}
-						index_valid = true;
+
 						switch (expr->get_datatype()) {
 							case TYPE_BVEC3: member_type = TYPE_BOOL; break;
 							case TYPE_VEC3: member_type = TYPE_FLOAT; break;
@@ -2745,7 +2744,7 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 							_set_error("Only integer constants are allowed as index at the moment");
 							return NULL;
 						}
-						index_valid = true;
+
 						switch (expr->get_datatype()) {
 							case TYPE_BVEC4: member_type = TYPE_BOOL; break;
 							case TYPE_VEC4: member_type = TYPE_FLOAT; break;
@@ -2760,11 +2759,6 @@ ShaderLanguage::Node *ShaderLanguage::_parse_expression(BlockNode *p_block, cons
 					}
 				}
 
-				if (!index_valid) {
-					_set_error("Invalid index");
-					return NULL;
-				}
-
 				OperatorNode *op = alloc_node<OperatorNode>();
 				op->op = OP_INDEX;
 				op->return_cache = member_type;
@@ -3662,7 +3656,8 @@ Error ShaderLanguage::_parse_shader(const Map<StringName, FunctionInfo> &p_funct
 					_set_error("void datatype not allowed here");
 					return ERR_PARSE_ERROR;
 				}
-				if (!uniform && type < TYPE_FLOAT && type > TYPE_VEC4) { // FIXME: always false! should it be || instead?
+
+				if (!uniform && (type < TYPE_FLOAT || type > TYPE_VEC4)) {
 					_set_error("Invalid type for varying, only float,vec2,vec3,vec4 allowed.");
 					return ERR_PARSE_ERROR;
 				}
diff --git a/servers/visual_server.cpp b/servers/visual_server.cpp
index f8640720cb..59dd1ab495 100644
--- a/servers/visual_server.cpp
+++ b/servers/visual_server.cpp
@@ -214,9 +214,9 @@ RID VisualServer::_make_test_cube() {
 			for (int k = 0; k < 3; k++) {
 
 				if (i < 3)
-					face_points[j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+					face_points[j][(i + k) % 3] = v[k];
 				else
-					face_points[3 - j][(i + k) % 3] = v[k] * (i >= 3 ? -1 : 1);
+					face_points[3 - j][(i + k) % 3] = -v[k];
 			}
 			normal_points[j] = Vector3();
 			normal_points[j][i % 3] = (i >= 3 ? -1 : 1);