How do I get the Git log for a specific branch only?

Question

Assuming the following Git history:

Branch1     B---C-------F---G
           /     \           \
Master    A-------D---E-------H

Doing a git log master gives the log entries in following order A-B-C-D-E-F-G-H. - but I'm interested in history of master-only (i.e A-D-E-H)

How can I "get rid" of the unwanted log-entries from Branch1? I tried a lot of options for git log, but I cannot find anything appropriate...

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This leads to a further thing I don't understand in this context:

Looking at the log-history given by git log master it shows how my branch master evolved (A-B-C-D-E-F-G-H).

But doing a git checkout HEAD~1 (assuming master=HEAD) gives me E (Evolution HEAD~3:A - HEAD~2:D - HEAD~1:E - HEAD:H -> A-D-E-H)

This is what I don't understand: the ancestor of H looking at git log is G, while the ancestor of H looking at git checkout is E.

I don't understand this - What's the ancestor of H: G or E?...

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Conclusion: What I would like to have are git log entries from HEAD to HEAD~n only (for example above n = 1...3). How can this be achieved? Is it possible at all?

Answer 1

What you're looking for is

git log --first-parent

Why that option is called --first-parent answers your question

I don't understand this - What's the ancestor of H: G or E?

The answer is: both. E is the first parent, but G is the second parent, because H is a merge commit. A merge commit is one that has more than one parent.