This diff bug is illustrated on try.discourse: http://try.discourse.org/t/testing-diffs-date-changing-content-diff-avatar/686/3?u=grschafer
Look at the 2 edit diffs of the 3rd post and you’ll notice that the following line:
Something that will magically appear without being highlighted in a diff.
appears between the diffs without being highlighted in green. That is, in “2 vs 3” the above line is present in version 2 of the file, but in “1 vs 2” it is missing in version 2 of the file.
This happened because I edited the post to add that sentence, saved the edit, then made a new edit soon after, where I added:
Because I submitted another change immediately after.
The 2nd edit is the only one that shows up in the diff, but the 1st edit didn’t get its own diff – it was overwritten because the 2nd edit happened so soon after the 1st edit. If diffs near each other in time are going to be grouped under 1 diff, they should be added rather than overwritten.
Let me know if you have any questions, because I know this text description is a bit unwieldy.