1 files changed, 190 insertions, 27 deletions

diff --git a/rebase-interactive.c b/rebase-interactive.c
index 68aff1dac2..d86b434b3d 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -1,10 +1,42 @@
 #include "cache.h"
 #include "commit.h"
-#include "rebase-interactive.h"
 #include "sequencer.h"
+#include "rebase-interactive.h"
 #include "strbuf.h"
+#include "commit-slab.h"
+#include "config.h"
+#include "dir.h"
+
+static const char edit_todo_list_advice[] =
+N_("You can fix this with 'git rebase --edit-todo' "
+"and then run 'git rebase --continue'.\n"
+"Or you can abort the rebase with 'git rebase"
+" --abort'.\n");
+
+enum missing_commit_check_level {
+	MISSING_COMMIT_CHECK_IGNORE = 0,
+	MISSING_COMMIT_CHECK_WARN,
+	MISSING_COMMIT_CHECK_ERROR
+};
+
+static enum missing_commit_check_level get_missing_commit_check_level(void)
+{
+	const char *value;
+
+	if (git_config_get_value("rebase.missingcommitscheck", &value) ||
+			!strcasecmp("ignore", value))
+		return MISSING_COMMIT_CHECK_IGNORE;
+	if (!strcasecmp("warn", value))
+		return MISSING_COMMIT_CHECK_WARN;
+	if (!strcasecmp("error", value))
+		return MISSING_COMMIT_CHECK_ERROR;
+	warning(_("unrecognized setting %s for option "
+		  "rebase.missingCommitsCheck. Ignoring."), value);
+	return MISSING_COMMIT_CHECK_IGNORE;
+}
 
-void append_todo_help(unsigned edit_todo, unsigned keep_empty,
+void append_todo_help(int command_count,
+		      const char *shortrevisions, const char *shortonto,
 		      struct strbuf *buf)
 {
 	const char *msg = _("\nCommands:\n"
@@ -24,6 +56,15 @@ void append_todo_help(unsigned edit_todo, unsigned keep_empty,
 ".       specified). Use -c <commit> to reword the commit message.\n"
 "\n"
 "These lines can be re-ordered; they are executed from top to bottom.\n");
+	unsigned edit_todo = !(shortrevisions && shortonto);
+
+	if (!edit_todo) {
+		strbuf_addch(buf, '\n');
+		strbuf_commented_addf(buf, Q_("Rebase %s onto %s (%d command)",
+					      "Rebase %s onto %s (%d commands)",
+					      command_count),
+				      shortrevisions, shortonto, command_count);
+	}
 
 	strbuf_add_commented_lines(buf, msg, strlen(msg));
 
@@ -46,46 +87,168 @@ void append_todo_help(unsigned edit_todo, unsigned keep_empty,
 			"the rebase will be aborted.\n\n");
 
 	strbuf_add_commented_lines(buf, msg, strlen(msg));
+}
+
+int edit_todo_list(struct repository *r, struct todo_list *todo_list,
+		   struct todo_list *new_todo, const char *shortrevisions,
+		   const char *shortonto, unsigned flags)
+{
+	const char *todo_file = rebase_path_todo(),
+		*todo_backup = rebase_path_todo_backup();
+	unsigned initial = shortrevisions && shortonto;
+	int incorrect = 0;
+
+	/* If the user is editing the todo list, we first try to parse
+	 * it.  If there is an error, we do not return, because the user
+	 * might want to fix it in the first place. */
+	if (!initial)
+		incorrect = todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list) |
+			file_exists(rebase_path_dropped());
+
+	if (todo_list_write_to_file(r, todo_list, todo_file, shortrevisions, shortonto,
+				    -1, flags | TODO_LIST_SHORTEN_IDS | TODO_LIST_APPEND_TODO_HELP))
+		return error_errno(_("could not write '%s'"), todo_file);
+
+	if (!incorrect &&
+	    todo_list_write_to_file(r, todo_list, todo_backup,
+				    shortrevisions, shortonto, -1,
+				    (flags | TODO_LIST_APPEND_TODO_HELP) & ~TODO_LIST_SHORTEN_IDS) < 0)
+		return error(_("could not write '%s'."), rebase_path_todo_backup());
+
+	if (launch_sequence_editor(todo_file, &new_todo->buf, NULL))
+		return -2;
+
+	strbuf_stripspace(&new_todo->buf, 1);
+	if (initial && new_todo->buf.len == 0)
+		return -3;
+
+	if (todo_list_parse_insn_buffer(r, new_todo->buf.buf, new_todo)) {
+		fprintf(stderr, _(edit_todo_list_advice));
+		return -4;
+	}
 
-	if (!keep_empty) {
-		msg = _("Note that empty commits are commented out");
-		strbuf_add_commented_lines(buf, msg, strlen(msg));
+	if (incorrect) {
+		if (todo_list_check_against_backup(r, new_todo)) {
+			write_file(rebase_path_dropped(), "");
+			return -4;
+		}
+
+		if (incorrect > 0)
+			unlink(rebase_path_dropped());
+	} else if (todo_list_check(todo_list, new_todo)) {
+		write_file(rebase_path_dropped(), "");
+		return -4;
 	}
+
+	return 0;
 }
 
-int edit_todo_list(struct repository *r, unsigned flags)
+define_commit_slab(commit_seen, unsigned char);
+/*
+ * Check if the user dropped some commits by mistake
+ * Behaviour determined by rebase.missingCommitsCheck.
+ * Check if there is an unrecognized command or a
+ * bad SHA-1 in a command.
+ */
+int todo_list_check(struct todo_list *old_todo, struct todo_list *new_todo)
 {
-	struct strbuf buf = STRBUF_INIT;
-	const char *todo_file = rebase_path_todo();
+	enum missing_commit_check_level check_level = get_missing_commit_check_level();
+	struct strbuf missing = STRBUF_INIT;
+	int res = 0, i;
+	struct commit_seen commit_seen;
 
-	if (strbuf_read_file(&buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
+	init_commit_seen(&commit_seen);
+
+	if (check_level == MISSING_COMMIT_CHECK_IGNORE)
+		goto leave_check;
+
+	/* Mark the commits in git-rebase-todo as seen */
+	for (i = 0; i < new_todo->nr; i++) {
+		struct commit *commit = new_todo->items[i].commit;
+		if (commit)
+			*commit_seen_at(&commit_seen, commit) = 1;
+	}
 
-	strbuf_stripspace(&buf, 1);
-	if (write_message(buf.buf, buf.len, todo_file, 0)) {
-		strbuf_release(&buf);
-		return -1;
+	/* Find commits in git-rebase-todo.backup yet unseen */
+	for (i = old_todo->nr - 1; i >= 0; i--) {
+		struct todo_item *item = old_todo->items + i;
+		struct commit *commit = item->commit;
+		if (commit && !*commit_seen_at(&commit_seen, commit)) {
+			strbuf_addf(&missing, " - %s %.*s\n",
+				    find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV),
+				    item->arg_len,
+				    todo_item_get_arg(old_todo, item));
+			*commit_seen_at(&commit_seen, commit) = 1;
+		}
 	}
 
-	strbuf_release(&buf);
+	/* Warn about missing commits */
+	if (!missing.len)
+		goto leave_check;
 
-	transform_todos(r, flags | TODO_LIST_SHORTEN_IDS);
+	if (check_level == MISSING_COMMIT_CHECK_ERROR)
+		res = 1;
 
-	if (strbuf_read_file(&buf, todo_file, 0) < 0)
-		return error_errno(_("could not read '%s'."), todo_file);
+	fprintf(stderr,
+		_("Warning: some commits may have been dropped accidentally.\n"
+		"Dropped commits (newer to older):\n"));
 
-	append_todo_help(1, 0, &buf);
-	if (write_message(buf.buf, buf.len, todo_file, 0)) {
-		strbuf_release(&buf);
-		return -1;
+	/* Make the list user-friendly and display */
+	fputs(missing.buf, stderr);
+	strbuf_release(&missing);
+
+	fprintf(stderr, _("To avoid this message, use \"drop\" to "
+		"explicitly remove a commit.\n\n"
+		"Use 'git config rebase.missingCommitsCheck' to change "
+		"the level of warnings.\n"
+		"The possible behaviours are: ignore, warn, error.\n\n"));
+
+	fprintf(stderr, _(edit_todo_list_advice));
+
+leave_check:
+	clear_commit_seen(&commit_seen);
+	return res;
+}
+
+int todo_list_check_against_backup(struct repository *r, struct todo_list *todo_list)
+{
+	struct todo_list backup = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&backup.buf, rebase_path_todo_backup(), 0) > 0) {
+		todo_list_parse_insn_buffer(r, backup.buf.buf, &backup);
+		res = todo_list_check(&backup, todo_list);
 	}
 
-	strbuf_release(&buf);
+	todo_list_release(&backup);
+	return res;
+}
+
+int check_todo_list_from_file(struct repository *r)
+{
+	struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
+	int res = 0;
 
-	if (launch_sequence_editor(todo_file, NULL, NULL))
-		return -1;
+	if (strbuf_read_file(&new_todo.buf, rebase_path_todo(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo());
+		goto out;
+	}
 
-	transform_todos(r, flags & ~(TODO_LIST_SHORTEN_IDS));
+	if (strbuf_read_file(&old_todo.buf, rebase_path_todo_backup(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo_backup());
+		goto out;
+	}
 
-	return 0;
+	res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
+	if (!res)
+		res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
+	if (res)
+		fprintf(stderr, _(edit_todo_list_advice));
+	if (!res)
+		res = todo_list_check(&old_todo, &new_todo);
+out:
+	todo_list_release(&old_todo);
+	todo_list_release(&new_todo);
+
+	return res;
 }