setStyle errors with some style objects

[adamal]

Since 0.42 I have been getting errors setting certain styles using map.setStyle(styleObject).
The errors remain in 0.43 and were not present in 0.41.

To reproduce:

• Open this plunker and open the console.
• Notice how the first style loads correctly initially.
• Click on map to switch to the other style. Works correctly.
• Click again to switch back to initial style. Nothing happens visually; I get several errors along the lines of:

Cannot read property 'r' of undefined
Cannot read property 'get' of undefined