RFR: 1431: The method TestPullRequest#diff sometimes returns wrong information

[Magnus Ihse Bursie]

On Mon, 22 Aug 2022 12:47:05 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> test/src/main/java/org/openjdk/skara/test/TestPullRequest.java line 257:
>> 
>>> 255:             var baseHash = sourceHash;
>>> 256:             var targetBranch = new Branch(targetRef());
>>> 257:             while (!"0".repeat(40).equals(baseHash.hex())) {
>> 
>> So if the common commit is more than 40 commits away, return "no diff"? :-)
>> 
>> This is only used in testing, right? If so, this you could get away with it, but I think a comment describing the limitations would be needed.
>
> I think you are misunderstanding the code. `"0".repeat(40)` just generates a string with 40 zeros, basically a null hash.
> 
> Looping to find the common ancestor is one way of doing it, but I would recommend checking out `git merge-base`. There is a method for it already on `GitRepository`.

I see. Yes, I misunderstood the code as looping backwards for a maximum of 40. Don't know how I got to that conclusion. My brain is apparently still partially stuck in vacation mode. I don't think I'm used to methods being called on a string literal.

-------------

PR: https://git.openjdk.org/skara/pull/1360