Separate each statement of the form "assert(a && b);" into "assert(a);" and "assert(b);" for more precise diagnostics, except for this clever use in drmmode_display.c where it was used to pass a hint to developers:
assert(num_infos <= 32 && "update return type");
The following potential advantages come to mind:
Assertion failure are often sporadic and users who report them may not be in a position to narrow them down further easily, so it is important to get as much precision from each assertion failure as possible.
It's often more readable, sometimes eliminating parentheses.
When using a debugger to step over an assertion failure in the first part of the statement, the second part is still tested.
Providing separate branch likelihood hints to the compiler in the form of separate assert statements does not require the compiler to be quite as smart to recognize that it should optimize both branches, although I do not know if that makes a difference for any compiler commonly used to compile X (that is, I suspect that they are all smart enough to realize is that "a && b" is likely true, then "a" is likely true and "b" is likely true).
I have confirmed that the resulting tree built without any apparent complaints about the assert statements, and I am running the resulting X server now.