Merge branch 'ag/rebase-merge-allow-ff-under-abbrev-command'

"git rebase" with the merge backend did not work well when the
rebase.abbreviateCommands configuration was set.

* ag/rebase-merge-allow-ff-under-abbrev-command:
  t3432: test `--merge' with `rebase.abbreviateCommands = true', too
  sequencer: don't abbreviate a command if it doesn't have a short form

Author: gitster

sequencer.c

@@ -1578,7 +1578,7 @@ static const char *command_to_string(const enum todo_command command)
 
 static char command_to_char(const enum todo_command command)
 {
-	if (command < TODO_COMMENT && todo_command_info[command].c)
+	if (command < TODO_COMMENT)
 		return todo_command_info[command].c;
 	return comment_line_char;
 }
@@ -4963,6 +4963,8 @@ static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_lis
 		max = num;
 
 	for (item = todo_list->items, i = 0; i < max; i++, item++) {
+		char cmd;
+
 		/* if the item is not a command write it and continue */
 		if (item->command >= TODO_COMMENT) {
 			strbuf_addf(buf, "%.*s\n", item->arg_len,
@@ -4971,8 +4973,9 @@ static void todo_list_to_strbuf(struct repository *r, struct todo_list *todo_lis
 		}
 
 		/* add command to the buffer */
-		if (flags & TODO_LIST_ABBREVIATE_CMDS)
-			strbuf_addch(buf, command_to_char(item->command));
+		cmd = command_to_char(item->command);
+		if ((flags & TODO_LIST_ABBREVIATE_CMDS) && cmd)
+			strbuf_addch(buf, cmd);
 		else
 			strbuf_addstr(buf, command_to_string(item->command));
 

t/t3432-rebase-fast-forward.sh

@@ -28,10 +28,12 @@ test_rebase_same_head () {
 	shift &&
 	cmp_f="$1" &&
 	shift &&
-	test_rebase_same_head_ $status_n $what_n $cmp_n " --apply" "$*" &&
-	test_rebase_same_head_ $status_f $what_f $cmp_f " --apply --no-ff" "$*"
-	test_rebase_same_head_ $status_n $what_n $cmp_n " --merge" "$*" &&
-	test_rebase_same_head_ $status_f $what_f $cmp_f " --merge --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 0 " --apply" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 0 " --apply --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 0 " --merge" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 0 " --merge --no-ff" "$*"
+	test_rebase_same_head_ $status_n $what_n $cmp_n 1 " --merge" "$*" &&
+	test_rebase_same_head_ $status_f $what_f $cmp_f 1 " --merge --no-ff" "$*"
 }
 
 test_rebase_same_head_ () {
@@ -41,9 +43,21 @@ test_rebase_same_head_ () {
 	shift &&
 	cmp="$1" &&
 	shift &&
+	abbreviate="$1" &&
+	shift &&
 	flag="$1"
 	shift &&
-	test_expect_$status "git rebase$flag $* with $changes is $what with $cmp HEAD" "
+	if test $abbreviate -eq 1
+	then
+		msg="git rebase$flag $* (rebase.abbreviateCommands = true) with $changes is $what with $cmp HEAD"
+	else
+		msg="git rebase$flag $* with $changes is $what with $cmp HEAD"
+	fi &&
+	test_expect_$status "$msg" "
+		if test $abbreviate -eq 1
+		then
+			test_config rebase.abbreviateCommands true
+		fi &&
 		oldhead=\$(git rev-parse HEAD) &&
 		test_when_finished 'git reset --hard \$oldhead' &&
 		cp .git/logs/HEAD expect &&