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When I run git log --oneline for example, it outputs a list of commits in chronologic order (descendent). My question is: What criteria git uses to sort this list? Does it use the author_date or the committer_date to order the result? Or it uses another? This can be an issue for me if it sort by committer_date as this attribute can change over time. I appreciate any help about this.

Savrige
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    As an extra note : try adding `--graph` to your `git log` commands to have a better view of how commits are ordered -- for example : to view the difference between `--date-order` and `--topo-order` – LeGEC Mar 13 '20 at 14:22

1 Answers1

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Actually the primary sort criterion is given by the parent-child relationships, which are always respected in log listings (if three commits are chained A->B->C they will never be displayed in A C B order, no matter the dates or the log options).

But when we are displaying commits from paralell branches, there is some freedom in the ordering. For this scenario, there exist the options --date-order --topo-order. And here, "date-order" (the default) means the committer_date. If you wish to sort by the author date, there is the additional option --author-date-order.

If you are listing commits from a single branch, then these options are irrelevant.

Doc: https://git-scm.com/docs/git-log#_commit_ordering

---1----2----4----7
    \              \
     3----5----6----8----9--

Suppose you have this commit history (copied from docs) where the horizontal coordinate corresponds to the (author) date. Then the log list will display:

date-order  topo-order      topo-order (alt)
   9             9              9  
   8             8              8  
   7             6              7  
   6             5              4  
   4             3              2  
   5             7              6  
   2             4              5  
   3             2              3  
   1             1              1

More info here

leonbloy
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  • topological is the default behavior? because in the docs it says "By default, the commits are shown in reverse chronological order." – Savrige Mar 13 '20 at 13:43
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    @Maigret Perhaps it's more clear now? If not, see the linked docs – leonbloy Mar 13 '20 at 13:49
  • let me see if a got it: if I want to traverse only commits in **one** branch (let's say master branch), it will follow the parent-child relationship order. But if I want to traverse all commits considering **n** possible branches, it will default to date-order (commiter_date) as the order criterion? I'm not considering here using additional options, just want to know the default behavior of git log. – Savrige Mar 13 '20 at 14:28
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    Not exactly. The commits in each (sub)branch are first ordered by parent-child. Then, paralell braches are intermixed by commiter_date order. See the figure in https://git-scm.com/docs/git-log#_commit_ordering – leonbloy Mar 13 '20 at 14:47
  • This answer incorrect. In order for log listings to respect the parent child relationships, `--topo-order` must be used. Otherwise `git log master` would return exactly the same result as `git log master --topo-order`. But, in reality, the results differ. – gilly3 Dec 21 '20 at 19:47