Current policy is to update code to the standard style when changing a
substantial portion of it.  Blocks of code can be passed through astyle
to ensure that their formatting is correct:

astyle --style=1tbs --indent=spaces=4 --align-pointer=name --max-code-length=100 --break-after-logical --indent-classes --indent-preprocessor --indent-col1-comments --min-conditional-indent=0 --pad-oper --add-brackets --convert-tabs

For example, from vi, set marks a and b around the block, then:
:'a,'b ! astyle  --style=1tbs --indent=spaces=4 --align-pointer=name --max-code-length=100 --break-after-logical --indent-classes --indent-preprocessor --indent-col1-comments --min-conditional-indent=0 --pad-oper --add-brackets --convert-tabs

Here's an example that illustrates the most common points of style.

int foo( int arg1, int *arg2 )
{
    if( arg1 < 5 ) {
        switch( *arg2 ) {
        case 0:
            return arg1 + 5;
            break;
        case 1:
            return arg1 + 7;
            break;
        default:
            return 0;
            break;
        }
    } else if( arg1 > 17 ) {
        int i = 0;
        while( i < arg1 ) {
            printf( _("Really long message that's pointless except for the number %d and for its "
                      "length as it's illustrative of how to break strings properly.\n"), i );
        }
    }
    return 0;
}
