doc: add an UPSTREAM BRANCHES section to pull/push/fetch

jvns · jvns · commit 0ec629d4037b · 2025-09-12T14:46:25.000-04:00
From user feedback: one user mentioned that they don't know what the
term "upstream branch" means. As far as I can tell, the most complete
description is under the `--track` option in `git branch`. Upstreams
are an important concept in Git and the `git branch` man page is not an
obvious place for that information to live.

There's also a very terse description of "upstream branch" in the
glossary that's missing a lot of key information, like the fact that the
upstream is used by `git status` and `git pull`, as well as a
description in `git-config` in `branch.&lt;name&gt;.remote` which doesn't
explain the relationship to `git status` either.

Since the `git pull`, `git push`, and `git fetch` man pages already
include sections on REMOTES and the syntax for URLs, add a section on
UPSTREAM BRANCHES to `urls-remotes.adoc` and rename it to
`urls-remotes-upstreams.adoc`. That's an awkward name but at least it's
clear what's in the file.

In the new UPSTREAM BRANCHES section, cover the various ways that
upstreams branches are automatically set in Git, since users may
mistakenly think that their branch does not have an upstream branch if
they didn't explicitly set one.

A terminology note: Git uses two terms for this concept:

- "tracking" as in "the current branch is _tracking_ some remote"
  or the `--track` option to `git branch`
- "upstream" or "upstream branch", as in `git push --set-upstream`.
  This term is also used in the `git rebase` man page to refer to the
  first argument to `git rebase`, as well as in `git pull` to refer to
  the branch which is going to be merged into the current branch ("merge
  the upstream branch into the current branch")

Use "upstream branch" as a heading for this concept even though the term
"upstream branch" is not always used strictly in the sense of "the
tracking information for the current branch". "Upstream" is used much
more often than "tracking" in the Git docs to refer to this concept and
the goal is to help users understand the docs.

Signed-off-by: Julia Evans &lt;julia@jvns.ca&gt;
diff --git a/Documentation/git-fetch.adoc b/Documentation/git-fetch.adoc
@@ -52,7 +52,7 @@ include::pull-fetch-param.adoc[]
 	Read refspecs, one per line, from stdin in addition to those provided
 	as arguments. The "tag <name>" format is not supported.
 
-include::urls-remotes.adoc[]
+include::urls-remotes-upstreams.adoc[]
 
 
 CONFIGURED REMOTE-TRACKING BRANCHES[[CRTB]]
diff --git a/Documentation/git-pull.adoc b/Documentation/git-pull.adoc
@@ -140,7 +140,7 @@ include::fetch-options.adoc[]
 
 include::pull-fetch-param.adoc[]
 
-include::urls-remotes.adoc[]
+include::urls-remotes-upstreams.adoc[]
 
 include::merge-strategies.adoc[]
 
diff --git a/Documentation/git-push.adoc b/Documentation/git-push.adoc
@@ -431,7 +431,7 @@ further recursion will occur. In this case, "only" is treated as "on-demand".
 --ipv6::
 	Use IPv6 addresses only, ignoring IPv4 addresses.
 
-include::urls-remotes.adoc[]
+include::urls-remotes-upstreams.adoc[]
 
 OUTPUT
 ------
diff --git a/Documentation/urls-remotes-upstreams.adoc b/Documentation/urls-remotes-upstreams.adoc
@@ -91,6 +91,41 @@ git push uses:
 	HEAD:refs/heads/<head>
 ------------
 
-
-
-
+UPSTREAM BRANCHES[[UPSTREAM-BRANCHES]]
+--------------------------------------
+
+Branches in Git can optionally have an upstream remote branch.
+Git defaults to using the upstream branch for remote operations, for example:
+
+* It's the default for `git pull` or `git fetch` with no arguments
+* It's sometimes the default for `git push` with no arguments. See the
+  `push.default` section of linkgit:git-config[1] for the details.
+* `git status` and `git branch -v` will show the
+  relationship between the current branch and the upstream,
+  for example "Your branch is up to date with origin/main"
+
+The upstream is stored in `.git/config`, in the "remote" and "merge"
+fields. For example, if `main`'s upstream is `origin/main`:
+
+```
+[branch "main"]
+   remote = origin
+   merge = refs/heads/main
+```
+
+You can set an upstream branch explicitly with
+`git push --set-upstream <remote> <branch>` or `git branch --track`,
+but Git will often automatically set the upstream for you, for example:
+
+* When you clone a repository, Git will automatically set the upstream
+  for the default branch.
+* If you have the `push.autoSetupRemote` configuration option set,
+  `git push` will automatically set the upstream the first time you push
+  a branch.
+* Checking out a remote-tracking branch with `git checkout <branch>`
+  will automatically create a local branch with that name and set
+  the upstream to the remote branch.
+
+[NOTE]
+Upstream branches are sometimes referred to as "tracking information",
+as in "set the branch's tracking information".
