pull: allow interactive rebase with --rebase=interactive

A couple of years ago, I found the need to collaborate on topic
branches that were rebased all the time, and I really needed to see
what I was rebasing when pulling, so I introduced an
interactively-rebasing pull.

The way builtin pull works, this change also supports the value
'interactive' for the 'branch.<name>.rebase' config variable, which
is a neat thing because users can now configure given branches for
interactively-rebasing pulls without having to type out the complete
`--rebase=interactive` option every time they pull.

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

Documentation/config.txt

@@ -870,6 +870,8 @@ When preserve, also pass `--preserve-merges` along to 'git rebase'
 so that locally committed merge commits will not be flattened
 by running 'git pull'.
 +
+When the value is `interactive`, the rebase is run in interactive mode.
++
 *NOTE*: this is a possibly dangerous operation; do *not* use
 it unless you understand the implications (see linkgit:git-rebase[1]
 for details).
@@ -2149,6 +2151,8 @@ When preserve, also pass `--preserve-merges` along to 'git rebase'
 so that locally committed merge commits will not be flattened
 by running 'git pull'.
 +
+When the value is `interactive`, the rebase is run in interactive mode.
++
 *NOTE*: this is a possibly dangerous operation; do *not* use
 it unless you understand the implications (see linkgit:git-rebase[1]
 for details).

Documentation/git-pull.txt

@@ -101,7 +101,7 @@ Options related to merging
 include::merge-options.txt[]
 
 -r::
---rebase[=false|true|preserve]::
+--rebase[=false|true|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
@@ -113,6 +113,8 @@ to `git rebase` so that locally created merge commits will not be flattened.
 +
 When false, merge the current branch into the upstream branch.
 +
+When `interactive`, enable the interactive mode of rebase.
++
 See `pull.rebase`, `branch.<name>.rebase` and `branch.autoSetupRebase` in
 linkgit:git-config[1] if you want to make `git pull` always use
 `--rebase` instead of merging.

builtin/pull.c

@@ -22,7 +22,8 @@ enum rebase_type {
 	REBASE_INVALID = -1,
 	REBASE_FALSE = 0,
 	REBASE_TRUE,
-	REBASE_PRESERVE
+	REBASE_PRESERVE,
+	REBASE_INTERACTIVE
 };
 
 /**
@@ -42,6 +43,8 @@ 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, "interactive"))
+		return REBASE_INTERACTIVE;
 
 	if (fatal)
 		die(_("Invalid value for %s: %s"), key, value);
@@ -112,7 +115,7 @@ 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",
+	  "false|true|preserve|interactive",
 	  N_("incorporate changes by rebasing rather than merging"),
 	  PARSE_OPT_OPTARG, parse_opt_rebase },
 	OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
@@ -772,6 +775,8 @@ static int run_rebase(const unsigned char *curr_head,
 	/* Options passed to git-rebase */
 	if (opt_rebase == REBASE_PRESERVE)
 		argv_array_push(&args, "--preserve-merges");
+	else if (opt_rebase == REBASE_INTERACTIVE)
+		argv_array_push(&args, "--interactive");
 	if (opt_diffstat)
 		argv_array_push(&args, opt_diffstat);
 	argv_array_pushv(&args, opt_strategies.argv);

t/t5520-pull.sh

@@ -326,6 +326,16 @@ test_expect_success 'pull.rebase=preserve rebases and merges keep-merge' '
 	test "$(git rev-parse HEAD^2)" = "$(git rev-parse keep-merge)"
 '
 
+test_expect_success 'pull.rebase=interactive' '
+	write_script "$TRASH_DIRECTORY/fake-editor" <<-\EOF &&
+	echo I was here >fake.out &&
+	false
+	EOF
+	test_set_editor "$TRASH_DIRECTORY/fake-editor" &&
+	test_must_fail git pull --rebase=interactive . copy &&
+	test "I was here" = "$(cat fake.out)"
+'
+
 test_expect_success 'pull.rebase=invalid fails' '
 	git reset --hard before-preserve-rebase &&
 	test_config pull.rebase invalid &&