git-commit-vandalism/rebase-interactive.c
Johannes Schindelin 26027625dd rebase -i: also avoid SHA-1 collisions with missingCommitsCheck
When `rebase.missingCommitsCheck` is in effect, we use the backup of the
todo list that was copied just before the user was allowed to edit it.

That backup is, of course, just as susceptible to the hash collision as
the todo list itself: a reworded commit could make a previously
unambiguous short commit ID ambiguous all of a sudden.

So let's not just copy the todo list, but let's instead write out the
backup with expanded commit IDs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-23 12:48:12 -08:00

192 lines
6.2 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"
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();
unsigned initial = shortrevisions && shortonto;
/* 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)
todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list);
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 (initial &&
todo_list_write_to_file(r, todo_list, rebase_path_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;
/* For the initial edit, the todo list gets parsed in
* complete_action(). */
if (!initial)
return todo_list_parse_insn_buffer(r, new_todo->buf.buf, new_todo);
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"));
leave_check:
clear_commit_seen(&commit_seen);
return res;
}