Vertex shader fill failed to compile

[ivovandongen]

Capturing this from #5610 (comment) so it doesn't get lost.

This crash happens when adding a Layer in the MapView#onMapReady callback. I've added a test case here to reproduce the issue (thanks @cammace)

08-02 10:14:44.321 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeAddLayer
08-02 10:14:44.321 4607-4607/? D/mbgl: {pboxsdk.testapp}[Android]: NativeMapView::activate
08-02 10:14:44.321 4607-4607/? D/mbgl: {pboxsdk.testapp}[Android]: NativeMapView::deactivate
08-02 10:14:44.322 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeLatLngForPixel
08-02 10:14:44.322 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeLatLngForPixel
08-02 10:14:44.322 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeLatLngForPixel
08-02 10:14:44.322 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeLatLngForPixel
08-02 10:14:44.322 4607-4607/? D/mbgl: {pboxsdk.testapp}[JNI]: nativeGetAnnotationsInBounds
08-02 10:14:44.323 4607-4607/? D/mbgl: {pboxsdk.testapp}[Android]: NativeMapView::notifyMapChange()
08-02 10:14:44.323 4607-4607/? E/libEGL: call to OpenGL ES API with no current context (logged once per thread)
08-02 10:14:44.323 4607-4607/? E/mbgl: {pboxsdk.testapp}[Shader]: Vertex shader fill failed to compile: precision highp float;
                                       #ifdef GL_ES
                                       precision highp float;
                                       #else
                                       #define lowp
                                       #define mediump
                                       #define highp
                                       #endif

                                       attribute vec2 a_pos;

                                       uniform mat4 u_matrix;

                                       uniform lowp vec4 u_color;
                                       uniform lowp float u_opacity;

                                       void main() {
                                           lowp vec4 color = u_color;
                                           lowp float opacity = u_opacity;

                                           gl_Position = u_matrix * vec4(a_pos, 0, 1);
                                       }
08-02 10:14:44.323 4607-4607/? D/AndroidRuntime: Shutting down VM

cc @tmpsantos @zugaldia @tobrun @cammace

[drmarkpowell]

Looks like I got this or something very similar trying out Mapbox Android SDK 4.2 beta 1 for the first time. Same shader failed to compile message, precision highp float;

[ivovandongen]

@drmarkpowell Was this on an emulator? And if so, might it be this bug: #5878

[ivovandongen]

This is no longer the case. cc @cammace