git/rebase-interactive.c
Alban Gruin 5a5445d878 rebase-interactive: warn if commit is dropped with `rebase --edit-todo'
When set to "warn" or "error", `rebase.missingCommitsCheck' would make
`rebase -i' warn if the user removed commits from the todo list to
prevent mistakes.  Unfortunately, `rebase --edit-todo' and `rebase
--continue' don't take it into account.

This adds the ability for `rebase --edit-todo' and `rebase --continue'
to check if commits were dropped by the user.  As both edit_todo_list()
and complete_action() parse the todo list and check for dropped commits,
the code doing so in the latter is removed to reduce duplication.
`edit_todo_list_advice' is removed from sequencer.c as it is no longer
used there.

This changes when a backup of the todo list is made.  Until now, it was
saved only once, before the initial edit.  Now, it is also made if the
original todo list has no errors or no dropped commits.  Thus, the
backup should be error-free.  Without this, sequencer_continue()
(`rebase --continue') could only compare the current todo list against
the original, unedited list.  Before this change, this file was only
used by edit_todo_list() and `rebase -p' to create the backup before
the initial edit, and check_todo_list_from_file(), only used by
`rebase -p' to check for dropped commits after its own initial edit.

If the edited list has an error, a file, `dropped', is created to
report the issue.  Otherwise, it is deleted.  Usually, the edited list
is compared against the list before editing, but if this file exists,
it will be compared to the backup.  Also, if the file exists,
sequencer_continue() checks the list for dropped commits.  If the
check was performed every time, it would fail when resuming a rebase
after resolving a conflict, as the backup will contain commits that
were picked, but they will not be in the new list.  It's safe to
ignore this check if `dropped' does not exist, because that means that
no errors were found at the last edition, so any missing commits here
have already been picked.

Five tests are added to t3404.  The tests for
`rebase.missingCommitsCheck = warn' and `rebase.missingCommitsCheck =
error' have a similar structure.  First, we start a rebase with an
incorrect command on the first line.  Then, we edit the todo list,
removing the first and the last lines.  This demonstrates that
`--edit-todo' notices dropped commits, but not when the command is
incorrect.  Then, we restore the original todo list, and edit it to
remove the last line.  This demonstrates that if we add a commit after
the initial edit, then remove it, `--edit-todo' will notice that it
has been dropped.  Then, the actual rebase takes place.  In the third
test, it is also checked that `--continue' will refuse to resume the
rebase if commits were dropped.  The fourth test checks that no errors
are raised when resuming a rebase after resolving a conflict, the fifth
checks that no errors are raised when editing the todo list after
pausing the rebase.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 14:14:57 -08:00

259 lines
8 KiB
C

#include "cache.h"
#include "commit.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 keep_empty, int command_count,
const char *shortrevisions, const char *shortonto,
struct strbuf *buf)
{
const char *msg = _("\nCommands:\n"
"p, pick <commit> = use commit\n"
"r, reword <commit> = use commit, but edit the commit message\n"
"e, edit <commit> = use commit, but stop for amending\n"
"s, squash <commit> = use commit, but meld into previous commit\n"
"f, fixup <commit> = like \"squash\", but discard this commit's log message\n"
"x, exec <command> = run command (the rest of the line) using shell\n"
"b, break = stop here (continue rebase later with 'git rebase --continue')\n"
"d, drop <commit> = remove commit\n"
"l, label <label> = label current HEAD with a name\n"
"t, reset <label> = reset HEAD to a label\n"
"m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]\n"
". create a merge commit using the original merge commit's\n"
". message (or the oneline, if no original merge commit was\n"
". 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));
if (get_missing_commit_check_level() == MISSING_COMMIT_CHECK_ERROR)
msg = _("\nDo not remove any line. Use 'drop' "
"explicitly to remove a commit.\n");
else
msg = _("\nIf you remove a line here "
"THAT COMMIT WILL BE LOST.\n");
strbuf_add_commented_lines(buf, msg, strlen(msg));
if (edit_todo)
msg = _("\nYou are editing the todo file "
"of an ongoing interactive rebase.\n"
"To continue rebase after editing, run:\n"
" git rebase --continue\n\n");
else
msg = _("\nHowever, if you remove everything, "
"the rebase will be aborted.\n\n");
strbuf_add_commented_lines(buf, msg, strlen(msg));
if (!keep_empty) {
msg = _("Note that empty commits are commented out");
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 (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;
}
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)
{
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;
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;
}
/* 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;
}
}
/* Warn about missing commits */
if (!missing.len)
goto leave_check;
if (check_level == MISSING_COMMIT_CHECK_ERROR)
res = 1;
fprintf(stderr,
_("Warning: some commits may have been dropped accidentally.\n"
"Dropped commits (newer to older):\n"));
/* 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);
}
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 (strbuf_read_file(&new_todo.buf, rebase_path_todo(), 0) < 0) {
res = error(_("could not read '%s'."), rebase_path_todo());
goto out;
}
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;
}
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;
}