docs: say that --rebase=preserve is deprecated

dscho · gitster · commit 7401ab92f8c9 · 2019-05-28T13:22:34.000-07:00
As of Git v2.22.0, the `--preserve-merges` backend of `git rebase` will
be officially deprecated in favor of the `--rebase-merges` backend.
Consequently, `git pull --rebase=preserve` will also be deprected. State
this explicitly.

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
@@ -112,8 +112,9 @@ When set to `merges`, rebase using `git rebase --rebase-merges` so that
 the local merge commits are included in the rebase (see
 linkgit:git-rebase[1] for details).
 +
-When set to preserve, rebase with the `--preserve-merges` option passed
-to `git rebase` so that locally created merge commits will not be flattened.
+When set to `preserve` (deprecated in favor of `merges`), rebase with the
+`--preserve-merges` option passed to `git rebase` so that locally created
+merge commits will not be flattened.
 +
 When false, merge the current branch into the upstream branch.
 +

Original file line number	Diff line number	Diff line change
@@ -112,8 +112,9 @@ When set to `merges`, rebase using `git rebase --rebase-merges` so that
`112`	`112`	`the local merge commits are included in the rebase (see`
`113`	`113`	`linkgit:git-rebase[1] for details).`
`114`	`114`	`+`
`115`		-When set to preserve, rebase with the `--preserve-merges` option passed
`116`		-to `git rebase` so that locally created merge commits will not be flattened.
	`115`	+When set to `preserve` (deprecated in favor of `merges`), rebase with the
	`116`	+`--preserve-merges` option passed to `git rebase` so that locally created
	`117`	`+merge commits will not be flattened.`
`117`	`118`	`+`
`118`	`119`	`When false, merge the current branch into the upstream branch.`
`119`	`120`	`+`