sequencer: make it clearer that commit descriptions are just comments

Every once in a while, users report that editing the commit summaries
in the todo list does not get reflected in the rebase operation,
suggesting that users are (a) only using one-line commit messages, and
(b) not understanding that the commit summaries are merely helpful
comments to help them find the right hashes.

It may be difficult to correct users' poor commit messages, but we can
at least try to make it clearer that the commit summaries are not
directives of some sort by inserting a comment character.

sequencer.c

@@ -5189,11 +5189,11 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 		/* Create a label */
 		strbuf_reset(&label);
-		if (skip_prefix(oneline.buf, "Merge ", &p1) &&
+		if (skip_prefix(oneline.buf, "# Merge ", &p1) &&
 		    (p1 = strchr(p1, '\'')) &&
 		    (p2 = strchr(++p1, '\'')))
 			strbuf_add(&label, p1, p2 - p1);
-		else if (skip_prefix(oneline.buf, "Merge pull request ",
+		else if (skip_prefix(oneline.buf, "# Merge pull request ",
 				     &p1) &&
 			 (p1 = strstr(p1, " from ")))
 			strbuf_addstr(&label, p1 + strlen(" from "));
@@ -5220,7 +5220,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 			strbuf_addstr(&buf, label_oid(oid, label.buf, &state));
 		}
-		strbuf_addf(&buf, " # %s", oneline.buf);
+		strbuf_addf(&buf, " %s", oneline.buf);
 
 		FLEX_ALLOC_STR(entry, string, buf.buf);
 		oidcpy(&entry->entry.oid, &commit->object.oid);
@@ -5302,7 +5302,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 			else {
 				strbuf_reset(&oneline);
 				pretty_print_commit(pp, commit, &oneline);
-				strbuf_addf(out, "%s %s # %s\n",
+				strbuf_addf(out, "%s %s %s\n",
 					    cmd_reset, to, oneline.buf);
 			}
 		}
@@ -5365,8 +5365,14 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 	git_config_get_string("rebase.instructionFormat", &format);
 	if (!format || !*format) {
 		free(format);
-		format = xstrdup("%s");
+		format = xstrdup("# %s");
 	}
+	if (*format != '#') {
+		char *temp = format;
+		format = xstrfmt("# %s", temp);
+		free(temp);
+	}
+
 	get_commit_format(format, &revs);
 	free(format);
 	pp.fmt = revs.commit_format;

t/t3404-rebase-interactive.sh

@@ -1388,7 +1388,7 @@ test_expect_success 'rebase -i respects rebase.missingCommitsCheck = warn' '
 	cat >expect <<-EOF &&
 	Warning: some commits may have been dropped accidentally.
 	Dropped commits (newer to older):
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary)
+	 - $(git log --format="%h # %s" -1 primary)
 	To avoid this message, use "drop" to explicitly remove a commit.
 	EOF
 	test_config rebase.missingCommitsCheck warn &&
@@ -1406,8 +1406,8 @@ test_expect_success 'rebase -i respects rebase.missingCommitsCheck = error' '
 	cat >expect <<-EOF &&
 	Warning: some commits may have been dropped accidentally.
 	Dropped commits (newer to older):
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary)
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary~2)
+	 - $(git log --format="%h # %s" -1 primary)
+	 - $(git log --format="%h # %s" -1 primary~2)
 	To avoid this message, use "drop" to explicitly remove a commit.
 
 	Use '\''git config rebase.missingCommitsCheck'\'' to change the level of warnings.
@@ -1449,11 +1449,11 @@ test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = ig
 
 test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = warn' '
 	cat >expect <<-EOF &&
-	error: invalid line 1: badcmd $(git rev-list --pretty=oneline --abbrev-commit -1 primary~4)
+	error: invalid line 1: badcmd $(git log --format="%h # %s" -1 primary~4)
 	Warning: some commits may have been dropped accidentally.
 	Dropped commits (newer to older):
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary)
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary~4)
+	 - $(git log --format="%h # %s" -1 primary)
+	 - $(git log --format="%h # %s" -1 primary~4)
 	To avoid this message, use "drop" to explicitly remove a commit.
 	EOF
 	head -n4 expect >expect.2 &&
@@ -1483,11 +1483,11 @@ test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = wa
 
 test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = error' '
 	cat >expect <<-EOF &&
-	error: invalid line 1: badcmd $(git rev-list --pretty=oneline --abbrev-commit -1 primary~4)
+	error: invalid line 1: badcmd $(git log --format="%h # %s" -1 primary~4)
 	Warning: some commits may have been dropped accidentally.
 	Dropped commits (newer to older):
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary)
-	 - $(git rev-list --pretty=oneline --abbrev-commit -1 primary~4)
+	 - $(git log --format="%h # %s" -1 primary)
+	 - $(git log --format="%h # %s" -1 primary~4)
 	To avoid this message, use "drop" to explicitly remove a commit.
 
 	Use '\''git config rebase.missingCommitsCheck'\'' to change the level of warnings.
@@ -1560,11 +1560,11 @@ test_expect_success 'respects rebase.abbreviateCommands with fixup, squash and e
 	test_commit "fixup! first" file2.txt "first line again" first_fixup &&
 	test_commit "squash! second" file1.txt "another line here" second_squash &&
 	cat >expected <<-EOF &&
-	p $(git rev-list --abbrev-commit -1 first) first
-	f $(git rev-list --abbrev-commit -1 first_fixup) fixup! first
+	p $(git rev-list --abbrev-commit -1 first) # first
+	f $(git rev-list --abbrev-commit -1 first_fixup) # fixup! first
 	x git show HEAD
-	p $(git rev-list --abbrev-commit -1 second) second
-	s $(git rev-list --abbrev-commit -1 second_squash) squash! second
+	p $(git rev-list --abbrev-commit -1 second) # second
+	s $(git rev-list --abbrev-commit -1 second_squash) # squash! second
 	x git show HEAD
 	EOF
 	git checkout abbrevcmd &&
@@ -1583,7 +1583,7 @@ test_expect_success 'static check of bad command' '
 		set_fake_editor &&
 		test_must_fail env FAKE_LINES="1 2 3 bad 4 5" \
 		git rebase -i --root 2>actual &&
-		test_i18ngrep "badcmd $(git rev-list --oneline -1 primary~1)" \
+		test_i18ngrep "badcmd $(git log --format="%h # %s" -1 primary~1)" \
 				actual &&
 		test_i18ngrep "You can fix this with .git rebase --edit-todo.." \
 				actual &&

t/t3415-rebase-autosquash.sh

@@ -280,10 +280,10 @@ test_auto_fixup_fixup () {
 		parent2=$(git rev-parse --short HEAD^^) &&
 		parent3=$(git rev-parse --short HEAD^^^) &&
 		cat >expected <<-EOF &&
-		pick $parent3 first commit
-		$1 $parent1 $1! first
-		$1 $head $1! $2! first
-		pick $parent2 second commit
+		pick $parent3 # first commit
+		$1 $parent1 # $1! first
+		$1 $head # $1! $2! first
+		pick $parent2 # second commit
 		EOF
 		test_cmp expected actual
 	) &&
@@ -358,7 +358,7 @@ test_expect_success 'autosquash with empty custom instructionFormat' '
 		set_cat_todo_editor &&
 		test_must_fail git -c rebase.instructionFormat= \
 			rebase --autosquash  --force-rebase -i HEAD^ >actual &&
-		git log -1 --format="pick %h %s" >expect &&
+		git log -1 --format="pick %h # %s" >expect &&
 		test_cmp expect actual
 	)
 '

t/t3430-rebase-merges.sh

@@ -106,18 +106,18 @@ test_expect_success 'generate correct todo list' '
 	label onto
 
 	reset onto
-	pick $b B
+	pick $b # B
 	label E
 
 	reset onto
-	pick $c C
+	pick $c # C
 	label branch-point
-	pick $f F
-	pick $g G
+	pick $f # F
+	pick $g # G
 	label H
 
 	reset branch-point # C
-	pick $d D
+	pick $d # D
 	merge -C $e E # E
 	merge -C $h H # H
 

t/t5520-pull.sh

@@ -796,7 +796,7 @@ test_expect_success 'git pull --rebase does not reapply old patches' '
 		cd dst &&
 		test_must_fail git pull --rebase &&
 		cat .git/rebase-merge/done .git/rebase-merge/git-rebase-todo >work &&
-		grep -v -e \# -e ^$ work >patches &&
+		sed -e s/#.*// work | grep -v ^$ >patches &&
 		test_line_count = 1 patches &&
 		rm -f work
 	)

t/t7512-status-help.sh

@@ -139,7 +139,7 @@ test_expect_success 'status during rebase -i when conflicts unresolved' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last command done (1 command done):
-   pick $LAST_COMMIT one_second
+   pick $LAST_COMMIT # one_second
 No commands remaining.
 You are currently rebasing branch '\''rebase_i_conflicts_second'\'' on '\''$ONTO'\''.
   (fix conflicts and then run "git rebase --continue")
@@ -168,7 +168,7 @@ test_expect_success 'status during rebase -i after resolving conflicts' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last command done (1 command done):
-   pick $LAST_COMMIT one_second
+   pick $LAST_COMMIT # one_second
 No commands remaining.
 You are currently rebasing branch '\''rebase_i_conflicts_second'\'' on '\''$ONTO'\''.
   (all conflicts fixed: run "git rebase --continue")
@@ -200,8 +200,8 @@ test_expect_success 'status when rebasing -i in edit mode' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   pick $COMMIT2 two_rebase_i
-   edit $COMMIT3 three_rebase_i
+   pick $COMMIT2 # two_rebase_i
+   edit $COMMIT3 # three_rebase_i
 No commands remaining.
 You are currently editing a commit while rebasing branch '\''rebase_i_edit'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -233,10 +233,10 @@ test_expect_success 'status when splitting a commit' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   pick $COMMIT2 two_split
-   edit $COMMIT3 three_split
+   pick $COMMIT2 # two_split
+   edit $COMMIT3 # three_split
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_split
+   pick $COMMIT4 # four_split
   (use "git rebase --edit-todo" to view and edit)
 You are currently splitting a commit while rebasing branch '\''split_commit'\'' on '\''$ONTO'\''.
   (Once your working directory is clean, run "git rebase --continue")
@@ -271,8 +271,8 @@ test_expect_success 'status after editing the last commit with --amend during a
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (3 commands done):
-   pick $COMMIT3 three_amend
-   edit $COMMIT4 four_amend
+   pick $COMMIT3 # three_amend
+   edit $COMMIT4 # four_amend
   (see more in file .git/rebase-merge/done)
 No commands remaining.
 You are currently editing a commit while rebasing branch '\''amend_last'\'' on '\''$ONTO'\''.
@@ -309,10 +309,10 @@ test_expect_success 'status: (continue first edit) second edit' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -340,10 +340,10 @@ test_expect_success 'status: (continue first edit) second edit and split' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently splitting a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (Once your working directory is clean, run "git rebase --continue")
@@ -375,10 +375,10 @@ test_expect_success 'status: (continue first edit) second edit and amend' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -406,10 +406,10 @@ test_expect_success 'status: (amend first edit) second edit' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -438,10 +438,10 @@ test_expect_success 'status: (amend first edit) second edit and split' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently splitting a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (Once your working directory is clean, run "git rebase --continue")
@@ -474,10 +474,10 @@ test_expect_success 'status: (amend first edit) second edit and amend' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -507,10 +507,10 @@ test_expect_success 'status: (split first edit) second edit' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -541,10 +541,10 @@ test_expect_success 'status: (split first edit) second edit and split' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently splitting a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (Once your working directory is clean, run "git rebase --continue")
@@ -579,10 +579,10 @@ test_expect_success 'status: (split first edit) second edit and amend' '
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   edit $COMMIT2 two_edits
-   edit $COMMIT3 three_edits
+   edit $COMMIT2 # two_edits
+   edit $COMMIT3 # three_edits
 Next command to do (1 remaining command):
-   pick $COMMIT4 four_edits
+   pick $COMMIT4 # four_edits
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_edits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -947,11 +947,11 @@ test_expect_success 'status: two commands done with some white lines in done fil
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (2 commands done):
-   pick $COMMIT2 two_commit
+   pick $COMMIT2 # two_commit
    exec exit 15
 Next commands to do (2 remaining commands):
-   pick $COMMIT3 three_commit
-   pick $COMMIT4 four_commit
+   pick $COMMIT3 # three_commit
+   pick $COMMIT4 # four_commit
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_commits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -975,12 +975,12 @@ test_expect_success 'status: two remaining commands with some white lines in tod
 	cat >expected <<EOF &&
 interactive rebase in progress; onto $ONTO
 Last commands done (3 commands done):
-   pick $COMMIT2 two_commit
+   pick $COMMIT2 # two_commit
    exec exit 15
   (see more in file .git/rebase-merge/done)
 Next commands to do (2 remaining commands):
-   pick $COMMIT3 three_commit
-   pick $COMMIT4 four_commit
+   pick $COMMIT3 # three_commit
+   pick $COMMIT4 # four_commit
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_commits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)
@@ -1000,7 +1000,7 @@ test_expect_success 'status: handle not-yet-started rebase -i gracefully' '
 On branch several_commits
 No commands done.
 Next command to do (1 remaining command):
-   pick $COMMIT four_commit
+   pick $COMMIT # four_commit
   (use "git rebase --edit-todo" to view and edit)
 You are currently editing a commit while rebasing branch '\''several_commits'\'' on '\''$ONTO'\''.
   (use "git commit --amend" to amend the current commit)