Merge branch 'en/ps-history-some' into seen

* en/ps-history-some:
  history: fix detached HEAD handling
  SQUASH ME: Fixups

Documentation/git-history.adoc

@@ -63,7 +63,7 @@ OPTIONS
 `--ref-action=(branches|head|print)`::
 	Control which references will be updated by the command, if any. With
 	`branches`, all local branches that point to commits which are
-	decendants of the original commit will be rewritten. With `head`, only
+	descendants of the original commit will be rewritten. With `head`, only
 	the current `HEAD` reference will be rewritten. With `print`, all
 	updates as they would be performed with `branches` are printed in a
 	format that can be consumed by linkgit:git-update-ref[1].

builtin/history.c

@@ -178,17 +178,23 @@ static int handle_reference_updates(enum ref_action action,
 {
 	const struct name_decoration *decoration;
 	struct replay_revisions_options opts = { 0 };
-	struct replay_result result = {
-		.final_oid = rewritten->object.oid,
-	};
+	struct replay_result result = { 0 };
 	struct ref_transaction *transaction = NULL;
 	struct strvec args = STRVEC_INIT;
 	struct strbuf err = STRBUF_INIT;
 	struct commit *head = NULL;
+	char *head_ref = NULL;
+	bool detached_head = false;
 	struct rev_info revs;
 	char hex[GIT_MAX_HEXSZ + 1];
 	int ret;
 
+	head_ref = refs_resolve_refdup(get_main_ref_store(repo), "HEAD",
+				       RESOLVE_REF_READING, NULL, NULL);
+	if (!strcmp(head_ref, "HEAD"))
+		detached_head = true;
+	free(head_ref);
+
 	repo_init_revisions(repo, &revs, NULL);
 	strvec_push(&args, "ignored");
 	strvec_push(&args, "--reverse");
@@ -233,9 +239,10 @@ static int handle_reference_updates(enum ref_action action,
 			goto out;
 		}
 
-		strvec_push(&args, oid_to_hex(&head->object.oid));
+		strvec_push(&args, "HEAD");
 	} else {
 		strvec_push(&args, "--branches");
+		strvec_push(&args, "HEAD");
 	}
 
 	setup_revisions_from_strvec(&args, &revs, NULL);
@@ -244,13 +251,14 @@ static int handle_reference_updates(enum ref_action action,
 
 	opts.onto = oid_to_hex_r(hex, &rewritten->object.oid);
 
-	ret = replay_revisions(repo, &revs, &opts, &result);
+	ret = replay_revisions(&revs, &opts, &result);
 	if (ret)
 		goto out;
 
 	switch (action) {
 	case REF_ACTION_DEFAULT:
 	case REF_ACTION_BRANCHES:
+	case REF_ACTION_HEAD:
 		transaction = ref_store_transaction_begin(get_main_ref_store(repo), 0, &err);
 		if (!transaction) {
 			ret = error(_("failed to begin ref transaction: %s"), err.buf);
@@ -279,9 +287,11 @@ static int handle_reference_updates(enum ref_action action,
 		     decoration;
 		     decoration = decoration->next)
 		{
-			if (decoration->type != DECORATION_REF_LOCAL)
+			if ((decoration->type != DECORATION_REF_HEAD ||
+			     (action != REF_ACTION_HEAD && !detached_head)) &&
+			    (decoration->type != DECORATION_REF_LOCAL ||
+			     action == REF_ACTION_HEAD))
 				continue;
-
 			ret = ref_transaction_update(transaction,
 						     decoration->name,
 						     &rewritten->object.oid,
@@ -300,13 +310,6 @@ static int handle_reference_updates(enum ref_action action,
 		}
 
 		break;
-	case REF_ACTION_HEAD:
-		ret = refs_update_ref(get_main_ref_store(repo), reflog_msg, "HEAD",
-				      &result.final_oid, &head->object.oid, 0,
-				      UPDATE_REFS_MSG_ON_ERR);
-		if (ret)
-			goto out;
-		break;
 	case REF_ACTION_PRINT:
 		for (size_t i = 0; i < result.updates_nr; i++)
 			printf("update %s %s %s\n",

builtin/replay.c

@@ -167,7 +167,7 @@ int cmd_replay(int argc,
 		revs.simplify_history = 0;
 	}
 
-	ret = replay_revisions(repo, &revs, &opts, &result);
+	ret = replay_revisions(&revs, &opts, &result);
 	if (ret)
 		goto cleanup;
 
@@ -220,11 +220,5 @@ cleanup:
 	strbuf_release(&reflog_msg);
 	release_revisions(&revs);
 
-	if (ret) {
-		if (result.merge_conflict)
-			return 1;
-		return 128;
-	}
-
-	return 0;
+	return ret;
 }

replay.c

@@ -5,11 +5,11 @@
 #include "hex.h"
 #include "merge-ort.h"
 #include "object-name.h"
-#include "oidset.h"
 #include "parse-options.h"
 #include "refs.h"
 #include "replay.h"
 #include "revision.h"
+#include "strmap.h"
 #include "tree.h"
 
 static const char *short_commit_name(struct repository *repo,
@@ -151,11 +151,20 @@ static void get_ref_information(struct repository *repo,
 static void set_up_replay_mode(struct repository *repo,
 			       struct rev_cmdline_info *cmd_info,
 			       const char *onto_name,
+			       bool *detached_head,
 			       char **advance_name,
 			       struct commit **onto,
 			       struct strset **update_refs)
 {
 	struct ref_info rinfo;
+	char *head_ref;
+
+	*detached_head = false;
+	head_ref = refs_resolve_refdup(get_main_ref_store(repo), "HEAD",
+				       RESOLVE_REF_READING, NULL, NULL);
+	if (!strcmp(head_ref, "HEAD"))
+		*detached_head = true;
+	free(head_ref);
 
 	get_ref_information(repo, cmd_info, &rinfo);
 	if (!rinfo.positive_refexprs)
@@ -256,7 +265,7 @@ static void replay_result_queue_update(struct replay_result *result,
 	result->updates_nr++;
 }
 
-int replay_revisions(struct repository *repo, struct rev_info *revs,
+int replay_revisions(struct rev_info *revs,
 		     struct replay_revisions_options *opts,
 		     struct replay_result *out)
 {
@@ -265,16 +274,18 @@ int replay_revisions(struct repository *repo, struct rev_info *revs,
 	struct commit *last_commit = NULL;
 	struct commit *commit;
 	struct commit *onto = NULL;
+	struct repository *repo = revs->repo;
 	struct merge_options merge_opt;
 	struct merge_result result = {
 		.clean = 1,
 	};
 	char *advance;
+	bool detached_head;
 	int ret;
 
 	advance = xstrdup_or_null(opts->advance);
-	set_up_replay_mode(repo, &revs->cmdline, opts->onto, &advance,
-			   &onto, &update_refs);
+	set_up_replay_mode(repo, &revs->cmdline, opts->onto,
+			   &detached_head, &advance, &onto, &update_refs);
 
 	/* FIXME: Should allow replaying commits with the first as a root commit */
 
@@ -316,7 +327,9 @@ int replay_revisions(struct repository *repo, struct rev_info *revs,
 		if (!decoration)
 			continue;
 		while (decoration) {
-			if (decoration->type == DECORATION_REF_LOCAL &&
+			if ((decoration->type == DECORATION_REF_LOCAL ||
+			     (decoration->type == DECORATION_REF_HEAD &&
+			      detached_head)) &&
 			    (opts->contained || strset_contains(update_refs,
 								decoration->name))) {
 				replay_result_queue_update(out, decoration->name,
@@ -328,8 +341,7 @@ int replay_revisions(struct repository *repo, struct rev_info *revs,
 	}
 
 	if (!result.clean) {
-		out->merge_conflict = true;
-		ret = -1;
+		ret = 1;
 		goto out;
 	}
 
@@ -339,8 +351,6 @@ int replay_revisions(struct repository *repo, struct rev_info *revs,
 					   &onto->object.oid,
 					   &last_commit->object.oid);
 
-	out->final_oid = last_commit->object.oid;
-
 	ret = 0;
 
 out:

replay.h

@@ -43,25 +43,6 @@ struct replay_result {
 		struct object_id new_oid;
 	} *updates;
 	size_t updates_nr, updates_alloc;
-
-	/* Set to true in case the replay failed with a merge conflict. */
-	bool merge_conflict;
-
-	/*
-	 * The final object ID that was rewritten. Note that this field has
-	 * somewhat special semantics and may or may not be what you want:
-	 *
-	 *   - If no commits were rewritten it will remain uninitialized.
-	 *
-	 *   - If a thicket of branches is rewritten it is undefined in which
-	 *     order those branches will be rewritten, and thus the final object
-	 *     ID may point to a different commit than you'd expect.
-	 *
-	 * That being said, this field can still be useful when you know that
-	 * you only replay a single strand of commits. In that case, the final
-	 * commit will point to the tip of the rewritten strand of commits.
-	 */
-	struct object_id final_oid;
 };
 
 void replay_result_release(struct replay_result *result);
@@ -73,7 +54,7 @@ void replay_result_release(struct replay_result *result);
  *
  * Returns 0 on success, a negative error code otherwise.
  */
-int replay_revisions(struct repository *repo, struct rev_info *revs,
+int replay_revisions(struct rev_info *revs,
 		     struct replay_revisions_options *opts,
 		     struct replay_result *out);
 

t/t3451-history-reword.sh

@@ -77,6 +77,53 @@ test_expect_success 'can reword commit in the middle' '
 	)
 '
 
+test_expect_success 'can reword commit in the middle even on detached head' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third_on_main &&
+		git checkout --detach HEAD^ &&
+		test_commit third_on_head &&
+
+		reword_with_message HEAD~ <<-EOF &&
+		second reworded
+		EOF
+
+		expect_log HEAD --branches --graph <<-\EOF
+		* third_on_head
+		| * third_on_main
+		|/  
+		* second reworded
+		* first
+		EOF
+	)
+'
+
+test_expect_success 'can reword the detached head' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		git checkout --detach HEAD &&
+		test_commit third &&
+
+		reword_with_message HEAD <<-EOF &&
+		third reworded
+		EOF
+
+		expect_log <<-\EOF
+		third reworded
+		second
+		first
+		EOF
+	)
+'
+
 test_expect_success 'can reword root commit' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&