Broken vertex shaders for Draco compressed meshes with vec3 per-vertex color

[likangning93]

Here's Draco and non-Draco versions of the model as glb: luyssport_Ftm_skysphere.zip

These were derived from https://sketchfab.com/3d-models/ftm-0970f30574d047b1976ba0aa6f2ef855, by Sketchfab user luyssport, used under CC Attribution-NonCommercial-ShareAlike: https://creativecommons.org/licenses/by-nc-sa/4.0/

The shader Cesium is generating:

uniform float gltf_u_dec_texcoord_0_normConstant;
uniform vec2 gltf_u_dec_texcoord_0_min;
vec2 gltf_a_dec_texcoord_0;
uniform float gltf_u_dec_position_normConstant;
uniform vec3 gltf_u_dec_position_min;
vec3 gltf_a_dec_position;
uniform float gltf_u_dec_normal_rangeConstant;
vec3 gltf_a_dec_normal;
uniform float gltf_u_dec_color_0_normConstant;
uniform vec3 gltf_u_dec_color_0_min;
vec3 gltf_a_dec_vertexColor;
attribute vec4 a_tangent;
attribute vec3 a_normal;
precision highp float;
uniform mat4 u_modelViewMatrix;
uniform mat4 u_projectionMatrix;
attribute vec3 a_position;
attribute vec2 a_texcoord_0;
varying vec2 v_texcoord_0;
attribute vec4 a_vertexColor;
varying vec4 v_vertexColor;
void gltf_decoded_COLOR_0() 
{
    vec3 weightedPosition = gltf_a_dec_position;
    vec4 position = vec4(weightedPosition, 1.0);
    position = u_modelViewMatrix * position;
    gl_Position = u_projectionMatrix * position;
    v_texcoord_0 = gltf_a_dec_texcoord_0;
  v_vertexColor = gltf_a_dec_vertexColor; // <<< here!
}

void gltf_decoded_NORMAL() {
    gltf_a_dec_vertexColor = gltf_u_dec_color_0_min + a_vertexColor * gltf_u_dec_color_0_normConstant;
    gltf_decoded_COLOR_0();
}

void gltf_decoded_POSITION() {
    gltf_a_dec_normal = czm_octDecode(a_normal.xy, gltf_u_dec_normal_rangeConstant).zxy;
    gltf_decoded_NORMAL();
}

void gltf_decoded_TEXCOORD_0() {
    gltf_a_dec_position = gltf_u_dec_position_min + a_position * gltf_u_dec_position_normConstant;
    gltf_decoded_POSITION();
}

void czm_depth_main() {
    gltf_a_dec_texcoord_0 = gltf_u_dec_texcoord_0_min + a_texcoord_0 * gltf_u_dec_texcoord_0_normConstant;
    gltf_decoded_TEXCOORD_0();
}

void main() 
{ 
    czm_depth_main(); 
    czm_vertexLogDepth(u_projectionMatrix * u_modelViewMatrix * vec4(gltf_a_dec_position.xyz, 1.0)); 
}