[PATCH 5/6] Documentation: merge: add a section about fast-forward

From

Jonathan Nieder <jrnieder@gmail.com>

Date

Jan 11, 2010, 08:39 UTC

Message-ID

<20100111083940.GE23806@progeny.tock>

In-Reply-To

<20100111082123.GA23742@progeny.tock>

Cc: Petr Baudis <pasky@suse.cz>,
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Documentation/git-merge.txt |   31 ++++++++++++++++++-------------
 1 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 8950aa4..ec9c6d3 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -82,6 +82,20 @@ the same state that would result from the merge anyway.)
 If all named commits are already ancestors of `HEAD`, 'git merge'
 will exit early with the message "Already up-to-date."
 
+FAST-FORWARD MERGE
+------------------
+
+Often the current branch head is an ancestor of the named commit.
+This is the most common case especially when invoked from 'git
+pull': you are tracking an upstream repository, you have committed
+no local changes, and now you want to update to a newer upstream
+revision.  In this case, a new commit is not needed to store the
+combined history; instead, the `HEAD` (along with the index) is
+updated to point at the named commit, without creating an extra
+merge commit.
+
+This behavior can be suppressed with the `--no-ff` option.
+
 include::merge-strategies.txt[]
 
 
@@ -94,19 +108,10 @@ HOW MERGE WORKS
 A merge is always between the current `HEAD` and one or more
 commits (usually, branch head or tag).
 
-Two kinds of merge can happen:
-
-* `HEAD` is already contained in the merged commit. This is the
-  most common case especially when invoked from 'git pull':
-  you are tracking an upstream repository, have committed no local
-  changes and now you want to update to a newer upstream revision.
-  Your `HEAD` (and the index) is updated to point at the merged
-  commit, without creating an extra merge commit.  This is
-  called "Fast-forward".
-
-* Both the merged commit and `HEAD` are independent and must be
-  tied together by a merge commit that has both of them as its parents.
-  The rest of this section describes this "True merge" case.
+Except in a fast-forward merge (see above), the branches to be
+merged must be tied together by a merge commit that has both of them
+as its parents.
+The rest of this section describes this "True merge" case.
 
 The chosen merge strategy merges the two commits into a single
 new source tree.

-- 
1.6.6