hwhw/kindlepdfviewer — pull request #279 by tigran123 (2012-09-14 16:40:48+00:00)
Title: Calculator: make it more robust.

Previously it was very easy to crash the application by entering invalid input into calculator, for example
things like these: ")(", "inf/0", "f()", etc. By using Lua pcall() function to execute not only the construction of
the expression, but also the calculation of the final result, the calculator is made more robust and safe-guarded from such crashes.