Merge branch 'js/get-short-oid-drop-cache'

A corner-case object name ambiguity while the sequencer machinery
is working (e.g. "rebase -i -x") has been (half) fixed.

* js/get-short-oid-drop-cache:
  get_oid(): when an object was not found, try harder
  sequencer: move stale comment into correct location
  sequencer: improve error message when an OID could not be parsed
  rebase -i: demonstrate obscure loose object cache bug

Author: gitster

sequencer.c

@@ -2137,7 +2137,8 @@ static int parse_insn_line(struct repository *r, struct todo_item *item,
 	item->arg_len = (int)(eol - item->arg);
 
 	if (status < 0)
-		return -1;
+		return error(_("could not parse '%.*s'"),
+			     (int)(end_of_object_name - bol), bol);
 
 	item->commit = lookup_commit_reference(r, &commit_oid);
 	return !item->commit;
@@ -3640,14 +3641,14 @@ static int pick_commits(struct repository *r,
 			res = do_exec(r, item->arg);
 			*end_of_arg = saved;
 
-			/* Reread the todo file if it has changed. */
 			if (res) {
 				if (opts->reschedule_failed_exec)
 					reschedule = 1;
 			} else if (stat(get_todo_path(opts), &st))
 				res = error_errno(_("could not stat '%s'"),
 						  get_todo_path(opts));
 			else if (match_stat_data(&todo_list->stat, &st)) {
+				/* Reread the todo file if it has changed. */
 				todo_list_release(todo_list);
 				if (read_populate_todo(r, todo_list, opts))
 					res = -1; /* message was printed */

sha1-name.c

@@ -442,6 +442,18 @@ static enum get_oid_result get_short_oid(const char *name, int len,
 	find_short_packed_object(&ds);
 	status = finish_object_disambiguation(&ds, oid);
 
+	/*
+	 * If we didn't find it, do the usual reprepare() slow-path,
+	 * since the object may have recently been added to the repository
+	 * or migrated from loose to packed.
+	 */
+	if (status == MISSING_OBJECT) {
+		reprepare_packed_git(the_repository);
+		find_short_object_filename(&ds);
+		find_short_packed_object(&ds);
+		status = finish_object_disambiguation(&ds, oid);
+	}
+
 	if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) {
 		struct oid_array collect = OID_ARRAY_INIT;
 

t/t3429-rebase-edit-todo.sh

@@ -11,4 +11,26 @@ test_expect_success 'rebase exec modifies rebase-todo' '
 	test -e F
 '
 
+test_expect_success SHA1 'loose object cache vs re-reading todo list' '
+	GIT_REBASE_TODO=.git/rebase-merge/git-rebase-todo &&
+	export GIT_REBASE_TODO &&
+	write_script append-todo.sh <<-\EOS &&
+	# For values 5 and 6, this yields SHA-1s with the same first two digits
+	echo "pick $(git rev-parse --short \
+		$(printf "%s\\n" \
+			"tree $EMPTY_TREE" \
+			"author A U Thor <[email protected]> $1 +0000" \
+			"committer A U Thor <[email protected]> $1 +0000" \
+			"" \
+			"$1" |
+		  git hash-object -t commit -w --stdin))" >>$GIT_REBASE_TODO
+
+	shift
+	test -z "$*" ||
+	echo "exec $0 $*" >>$GIT_REBASE_TODO
+	EOS
+
+	git rebase HEAD -x "./append-todo.sh 5 6"
+'
+
 test_done