[IvyMike]

We can go deeper...

  if(
  	b != nil &&
  	b->qid.type == a->qid.type &&
  	b->qid.path == a->qid.path &&
  	b->qid.vers == a->qid.vers &&
  	b->dev      == a->dev &&
  	b->type     == a->type
  ) {
  	fprint(2, "cp: %s and %s are the same file\n", an, bn);
  	ret = 1;
  }

(Lined up the "a"s to make it obvious that they're all the same.)

[MaulingMonkey]

I'd prefer some variation on:

    int samedirfile( Dir *a, Dir *b )
    {
            if( a == b )
                    return 1;
    
            return  ( a && b ) &&
                    ( a->qid.type == b->qid.type ) &&
                    ( a->qid.path == b->qid.path ) &&
                    ( a->qid.vers == b->qid.vers ) &&
                    ( a->dev      == b->dev ) &&
                    ( a->type     == b->type );
    }
    
    ...
    
    if( samedirfile( a, b ) ) {
            fprint(2, "cp: %s and %s are the same file\n", an, bn);
            ret = 1;
    }

[tricolon]

I think it's fascinating that we prefer styles that are almost opposites:

    int samedirfile(Dir *a, Dir *b) {
        if(a == b) {
            return 1;
        }

        return (a && b)
            && (a->qid.type == b->qid.type)
            && (a->qid.path == b->qid.path)
            && (a->qid.vers == b->qid.vers)
            && (a->dev == b->dev)
            && (a->type == b->type);
    }
    
    ...
    
    if(samedirfile(a, b)) {
        fprint(2, "cp: %s and %s are the same file\n", an, bn);
        ret = 1;
    }

[MaulingMonkey]

I'll note I actually have a slight preference for prepended continuation operators like you have, but I stick to the style used at work for the sake of my sanity in trying to write consistent code.

[drivebyacct2]

I'm so, so, so glad that new languages are banning braceless if/else bodies.

[MaulingMonkey]

So how about that python? </trololololo>

[drivebyacct2]

I should have of course said "some" :)