What are the differences between double-dot “..” and triple-dot “…” in Git diff commit ranges?

Question

What are the differences between the following commands?:

git diff foo master   # a 
git diff foo..master  # b
git d         


        

Answer 1

The top picture is equivalent to the bottom graph tree

A0 <- A1 <- A2 <- A3 (master)
   \
    C0 <- C1 (test)

A picture is worth a thousand words, the difference between .. ... ^ is shown below.

$ git log master..test
# output C0 C1

$ git log ^master test
# output C0 C1

$ git log master…test
# output A1 A2 A3 C0 C1