with gcc 4.3.2

Compiling MySQL with gcc 4.3.2 and later produces a number of 
warnings, many of which are new with the recent compiler
versions.

This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number 
of the warnings, predominantly "suggest using parentheses 
around && in ||", and empty for and while bodies.