Re: [PATCH] t5310-pack-bitmaps: fix bogus 'pack-objects to file can use bitmap' test

Jeff King [off-list ref] writes:

quoted

quoted

If we assume that "expect" is first (which is our convention but not
necessarily guaranteed), then I think the best logic is something like:

  if $1 is empty; then
    bug in the test script
  elif test_cmp_allow_empty "$@"
    test failure

We do not need to check $2 at all. An empty one is either irrelevant (if
the expectation is empty), or a test failure (because it would not match
the non-empty $1).

... this is indeed a better solution. I written out the cases for
updated test_cmp to straighten out my thinking:

I'd be OK pursuing either this line, or what you showed originally.

As I do find [1] to be a real concern, I'd prefer not to flag empty
input to test_cmp as special.  But if we _were_ to do something, I
agree that "$2 can be anything---that is the output from the
potentially buggy program we are testing" is the right attitude to
take.

[Footnote]

*1*
https://public-inbox.org/git/CAM0VKjkT7fBJRie_3f4B13BHT9hp9MxRhuX5r1sogh2x7KQzbg@mail.gmail.com/