pull: accept --rebase=recreate to recreate the branch topology

Similar to the `preserve` mode simply passing the `--preserve-merges`
option to the `rebase` command, the `recreate` mode simply passes the
`--recreate-merges` option.

This will allow users to conveniently rebase non-trivial commit
topologies when pulling new commits, without flattening them.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

5 files changed, 25 insertions, 6 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0e25b2c92b..da41ab246d 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1058,6 +1058,10 @@ branch.<name>.rebase::
 	"git pull" is run. See "pull.rebase" for doing this in a non
 	branch-specific manner.
 +
+When recreate, also pass `--recreate-merges` along to 'git rebase'
+so that locally committed merge commits will not be flattened
+by running 'git pull'.
++
 When preserve, also pass `--preserve-merges` along to 'git rebase'
 so that locally committed merge commits will not be flattened
 by running 'git pull'.
@@ -2607,6 +2611,10 @@ pull.rebase::
 	pull" is run. See "branch.<name>.rebase" for setting this on a
 	per-branch basis.
 +
+When recreate, also pass `--recreate-merges` along to 'git rebase'
+so that locally committed merge commits will not be flattened
+by running 'git pull'.
++
 When preserve, also pass `--preserve-merges` along to 'git rebase'
 so that locally committed merge commits will not be flattened
 by running 'git pull'.
diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
index ce05b7a5b1..b4f9f057ea 100644
--- a/Documentation/git-pull.txt
+++ b/Documentation/git-pull.txt
@@ -101,13 +101,16 @@ Options related to merging
 include::merge-options.txt[]
 
 -r::
---rebase[=false|true|preserve|interactive]::
+--rebase[=false|true|recreate|preserve|interactive]::
 	When true, rebase the current branch on top of the upstream
 	branch after fetching. If there is a remote-tracking branch
 	corresponding to the upstream branch and the upstream branch
 	was rebased since last fetched, the rebase uses that information
 	to avoid rebasing non-local changes.
 +
+When set to recreate, rebase with the `--recreate-merges` option passed
+to `git rebase` so that locally created merge commits will not be flattened.
++
 When set to preserve, rebase with the `--preserve-merges` option passed
 to `git rebase` so that locally created merge commits will not be flattened.
 +
diff --git a/builtin/pull.c b/builtin/pull.c
index 511dbbe0f6..e33c84e034 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -27,14 +27,16 @@ enum rebase_type {
 	REBASE_FALSE = 0,
 	REBASE_TRUE,
 	REBASE_PRESERVE,
+	REBASE_RECREATE,
 	REBASE_INTERACTIVE
 };
 
 /**
  * Parses the value of --rebase. If value is a false value, returns
  * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
- * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
- * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
+ * "recreate", returns REBASE_RECREATE. If value is "preserve", returns
+ * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if
+ * fatal is true, otherwise returns REBASE_INVALID.
  */
 static enum rebase_type parse_config_rebase(const char *key, const char *value,
 		int fatal)
@@ -47,6 +49,8 @@ static enum rebase_type parse_config_rebase(const char *key, const char *value,
 		return REBASE_TRUE;
 	else if (!strcmp(value, "preserve"))
 		return REBASE_PRESERVE;
+	else if (!strcmp(value, "recreate"))
+		return REBASE_RECREATE;
 	else if (!strcmp(value, "interactive"))
 		return REBASE_INTERACTIVE;
 
@@ -130,7 +134,7 @@ static struct option pull_options[] = {
 	/* Options passed to git-merge or git-rebase */
 	OPT_GROUP(N_("Options related to merging")),
 	{ OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
-	  "false|true|preserve|interactive",
+	  "false|true|recreate|preserve|interactive",
 	  N_("incorporate changes by rebasing rather than merging"),
 	  PARSE_OPT_OPTARG, parse_opt_rebase },
 	OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
@@ -798,7 +802,9 @@ static int run_rebase(const struct object_id *curr_head,
 	argv_push_verbosity(&args);
 
 	/* Options passed to git-rebase */
-	if (opt_rebase == REBASE_PRESERVE)
+	if (opt_rebase == REBASE_RECREATE)
+		argv_array_push(&args, "--recreate-merges");
+	else if (opt_rebase == REBASE_PRESERVE)
 		argv_array_push(&args, "--preserve-merges");
 	else if (opt_rebase == REBASE_INTERACTIVE)
 		argv_array_push(&args, "--interactive");
diff --git a/builtin/remote.c b/builtin/remote.c
index d95bf904c3..b7d0f7ce59 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -306,6 +306,8 @@ static int config_read_branches(const char *key, const char *value, void *cb)
 				info->rebase = v;
 			else if (!strcmp(value, "preserve"))
 				info->rebase = NORMAL_REBASE;
+			else if (!strcmp(value, "recreate"))
+				info->rebase = NORMAL_REBASE;
 			else if (!strcmp(value, "interactive"))
 				info->rebase = INTERACTIVE_REBASE;
 		}
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 6893c3adab..6f98c96fee 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -2182,7 +2182,7 @@ _git_config ()
 		return
 		;;
 	branch.*.rebase)
-		__gitcomp "false true preserve interactive"
+		__gitcomp "false true recreate preserve interactive"
 		return
 		;;
 	remote.pushdefault)