Program: 942
Project: 942
Buggy source:
private void renderOpaque(SetMultimap<Material,EntityRef> meshByMaterial){
  Vector3f cameraPosition=worldRenderer.getActiveCamera().getPosition();
  Quat4f worldRot=new Quat4f();
  Vector3f worldPos=new Vector3f();
  Matrix4f matrixWorldSpace=new Matrix4f();
  Transform transWorldSpace=new Transform();
  Matrix4f matrixCameraSpace=new Matrix4f();
  FloatBuffer tempMatrixBuffer44=BufferUtils.createFloatBuffer(16);
  FloatBuffer tempMatrixBuffer33=BufferUtils.createFloatBuffer(12);
  for (  Material material : meshByMaterial.keys()) {
    OpenGLMesh lastMesh=null;
    material.enable();
    material.setFloat("String_Node_Str",1.0f);
    material.setFloat("String_Node_Str",1.0f);
    material.setMatrix4("String_Node_Str",worldRenderer.getActiveCamera().getProjectionMatrix());
    material.bindTextures();
    lastRendered=meshByMaterial.get(material).size();
    for (    EntityRef entity : meshByMaterial.get(material)) {
      MeshComponent meshComp=entity.getComponent(MeshComponent.class);
      LocationComponent location=entity.getComponent(LocationComponent.class);
      if (location == null || meshComp.mesh == null) {
        continue;
      }
      if (meshComp.mesh.isDisposed()) {
        logger.error("String_Node_Str");
        continue;
      }
      location.getWorldRotation(worldRot);
      location.getWorldPosition(worldPos);
      float worldScale=location.getWorldScale();
      matrixWorldSpace.set(worldRot,worldPos,worldScale);
      transWorldSpace.set(matrixWorldSpace);
      Vector3f worldPositionCameraSpace=new Vector3f();
      worldPositionCameraSpace.sub(worldPos,cameraPosition);
      matrixCameraSpace.set(worldRot,worldPositionCameraSpace,worldScale);
      AABB aabb=meshComp.mesh.getAABB().transform(transWorldSpace);
      boolean visible=worldRenderer.isAABBVisible(aabb);
      if (visible) {
        if (worldRenderer.isAABBVisible(aabb)) {
          if (meshComp.mesh != lastMesh) {
            if (lastMesh != null) {
              lastMesh.postRender();
            }
            lastMesh=(OpenGLMesh)meshComp.mesh;
            lastMesh.preRender();
          }
          Matrix4f modelViewMatrix=MatrixUtils.calcModelViewMatrix(worldRenderer.getActiveCamera().getViewMatrix(),matrixCameraSpace);
          MatrixUtils.matrixToFloatBuffer(modelViewMatrix,tempMatrixBuffer44);
          material.setMatrix4("String_Node_Str",tempMatrixBuffer44,true);
          MatrixUtils.matrixToFloatBuffer(MatrixUtils.calcNormalMatrix(modelViewMatrix),tempMatrixBuffer33);
          material.setMatrix3("String_Node_Str",tempMatrixBuffer33,true);
          material.setFloat("String_Node_Str",worldRenderer.getSunlightValueAt(worldPos),true);
          material.setFloat("String_Node_Str",worldRenderer.getBlockLightValueAt(worldPos),true);
          if (lastMesh != null) {
            lastMesh.doRender();
          }
        }
      }
    }
    if (lastMesh != null) {
      lastMesh.postRender();
    }
  }
}

Fixed version (ground truth):
private void renderOpaque(SetMultimap<Material,EntityRef> meshByMaterial){
  Vector3f cameraPosition=worldRenderer.getActiveCamera().getPosition();
  Quat4f worldRot=new Quat4f();
  Vector3f worldPos=new Vector3f();
  Matrix4f matrixWorldSpace=new Matrix4f();
  Transform transWorldSpace=new Transform();
  Matrix4f matrixCameraSpace=new Matrix4f();
  FloatBuffer tempMatrixBuffer44=BufferUtils.createFloatBuffer(16);
  FloatBuffer tempMatrixBuffer33=BufferUtils.createFloatBuffer(12);
  for (  Map.Entry<Material,Collection<EntityRef>> materialEntries : meshByMaterial.asMap().entrySet()) {
    Material material=materialEntries.getKey();
    OpenGLMesh lastMesh=null;
    material.enable();
    material.setFloat("String_Node_Str",1.0f);
    material.setFloat("String_Node_Str",1.0f);
    material.setMatrix4("String_Node_Str",worldRenderer.getActiveCamera().getProjectionMatrix());
    material.bindTextures();
    lastRendered=materialEntries.getValue().size();
    for (    EntityRef entity : materialEntries.getValue()) {
      MeshComponent meshComp=entity.getComponent(MeshComponent.class);
      LocationComponent location=entity.getComponent(LocationComponent.class);
      if (location == null || meshComp.mesh == null) {
        continue;
      }
      if (meshComp.mesh.isDisposed()) {
        logger.error("String_Node_Str");
        continue;
      }
      location.getWorldRotation(worldRot);
      location.getWorldPosition(worldPos);
      float worldScale=location.getWorldScale();
      matrixWorldSpace.set(worldRot,worldPos,worldScale);
      transWorldSpace.set(matrixWorldSpace);
      Vector3f worldPositionCameraSpace=new Vector3f();
      worldPositionCameraSpace.sub(worldPos,cameraPosition);
      matrixCameraSpace.set(worldRot,worldPositionCameraSpace,worldScale);
      AABB aabb=meshComp.mesh.getAABB().transform(transWorldSpace);
      boolean visible=worldRenderer.isAABBVisible(aabb);
      if (visible) {
        if (worldRenderer.isAABBVisible(aabb)) {
          if (meshComp.mesh != lastMesh) {
            if (lastMesh != null) {
              lastMesh.postRender();
            }
            lastMesh=(OpenGLMesh)meshComp.mesh;
            lastMesh.preRender();
          }
          Matrix4f modelViewMatrix=MatrixUtils.calcModelViewMatrix(worldRenderer.getActiveCamera().getViewMatrix(),matrixCameraSpace);
          MatrixUtils.matrixToFloatBuffer(modelViewMatrix,tempMatrixBuffer44);
          material.setMatrix4("String_Node_Str",tempMatrixBuffer44,true);
          MatrixUtils.matrixToFloatBuffer(MatrixUtils.calcNormalMatrix(modelViewMatrix),tempMatrixBuffer33);
          material.setMatrix3("String_Node_Str",tempMatrixBuffer33,true);
          material.setFloat("String_Node_Str",worldRenderer.getSunlightValueAt(worldPos),true);
          material.setFloat("String_Node_Str",worldRenderer.getBlockLightValueAt(worldPos),true);
          if (lastMesh != null) {
            lastMesh.doRender();
          }
        }
      }
    }
    if (lastMesh != null) {
      lastMesh.postRender();
    }
  }
}