Crash after adding clipping plane to empty clipping plane collection

[lilleyse]

Cesium crashes when adding a clipping plane to an empty clipping plane collection. It does not crash if the collection already has at least one plane in it. Seems to affect all the different types of objects that clipping planes can be applied to.

Model Example
3D Tiles Example
Terrain example
Point Cloud Example

RuntimeError: Fragment shader failed to compile.  Compile log: ERROR: 0:24: 'NaN' : undeclared identifier
ERROR: 0:24: '.0' : syntax error

Error
    at new RuntimeError (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:4365:19)
    at createAndLinkProgram (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:100439:23)
    at initialize (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:100660:23)
    at ShaderProgram._bind (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:100677:9)
    at beginDraw (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:175514:23)
    at Context.draw (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:175576:9)
    at DrawCommand.execute (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:96653:17)
    at executeCommand (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:239176:21)
    at executeCommands (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:239555:17)
    at executeCommandsInViewport (https://cesiumjs.org/Cesium/Build/CesiumUnminified/Cesium.js:239968:9)

[lilleyse]

@OmarShehata could you investigate this?

[OmarShehata]

I'm taking a look now.