I've seen various open source libraries (actually I've seen it for assets as well) having a home-baked license in the following manner :

SomeGuy's License:
1. You can use this code freely in commercial projects and modify it as you wish, but not sell it
2. If you want to sell a modified version, drop me an email first, or give credits to me

Edit:

The above example is ambiguous, so I am giving another one, I want to know if 3 lines of license will hold some ground:

SomeGuy's License:
1. You can use this code in a commercial project as a 3rd party library
2. You can't sell it as a derivative work

I know that such license is not polished at all, for example the Creative Commons set of licenses seem to be short, but actually have some large legal stuff underneath it, but I wonder if at least some level of protection can be gained with a hobby license like that ?

My question is, could this hold any ground in the court, or would the corporative lawyers of the company X tear it apart ?