diff options
Diffstat (limited to 'builtin')
| -rw-r--r-- | builtin/history.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/builtin/history.c b/builtin/history.c index cb251ae2e0..cae841707d 100644 --- a/builtin/history.c +++ b/builtin/history.c @@ -1,6 +1,7 @@ #define USE_THE_REPOSITORY_VARIABLE #include "builtin.h" +#include "cache-tree.h" #include "commit-reach.h" #include "commit.h" #include "config.h" @@ -8,17 +9,22 @@ #include "environment.h" #include "gettext.h" #include "hex.h" +#include "oidmap.h" #include "parse-options.h" +#include "path.h" +#include "read-cache.h" #include "refs.h" #include "replay.h" #include "reset.h" #include "revision.h" +#include "run-command.h" #include "sequencer.h" #include "strvec.h" #include "tree.h" #include "wt-status.h" #define GIT_HISTORY_REWORD_USAGE N_("git history reword <commit>") +#define GIT_HISTORY_SPLIT_USAGE N_("git history split <commit> [--] [<pathspec>...]") static int collect_commits(struct repository *repo, struct commit *old_commit, @@ -323,6 +329,216 @@ out: return ret; } +static int split_commit(struct repository *repo, + struct commit *original_commit, + struct pathspec *pathspec, + struct object_id *out) +{ + struct interactive_options interactive_opts = INTERACTIVE_OPTIONS_INIT; + struct strbuf index_file = STRBUF_INIT, split_message = STRBUF_INIT; + struct child_process read_tree_cmd = CHILD_PROCESS_INIT; + struct index_state index = INDEX_STATE_INIT(repo); + struct object_id original_commit_tree_oid, parent_tree_oid; + const char *original_message, *original_body, *ptr; + char original_commit_oid[GIT_MAX_HEXSZ + 1]; + char *original_author = NULL; + struct commit_list *parents = NULL; + struct commit *first_commit; + struct tree *split_tree; + size_t len; + int ret; + + if (original_commit->parents) + parent_tree_oid = *get_commit_tree_oid(original_commit->parents->item); + else + oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree); + original_commit_tree_oid = *get_commit_tree_oid(original_commit); + + /* + * Construct the first commit. This is done by taking the original + * commit parent's tree and selectively patching changes from the diff + * between that parent and its child. + */ + repo_git_path_replace(repo, &index_file, "%s", "history-split.index"); + + read_tree_cmd.git_cmd = 1; + strvec_pushf(&read_tree_cmd.env, "GIT_INDEX_FILE=%s", index_file.buf); + strvec_push(&read_tree_cmd.args, "read-tree"); + strvec_push(&read_tree_cmd.args, oid_to_hex(&parent_tree_oid)); + ret = run_command(&read_tree_cmd); + if (ret < 0) + goto out; + + ret = read_index_from(&index, index_file.buf, repo->gitdir); + if (ret < 0) { + ret = error(_("failed reading temporary index")); + goto out; + } + + oid_to_hex_r(original_commit_oid, &original_commit->object.oid); + ret = run_add_p_index(repo, &index, index_file.buf, &interactive_opts, + original_commit_oid, pathspec); + if (ret < 0) + goto out; + + split_tree = write_in_core_index_as_tree(repo, &index); + if (!split_tree) { + ret = error(_("failed split tree")); + goto out; + } + + unlink(index_file.buf); + + /* + * We disallow the cases where either the split-out commit or the + * original commit would become empty. Consequently, if we see that the + * new tree ID matches either of those trees we abort. + */ + if (oideq(&split_tree->object.oid, &parent_tree_oid)) { + ret = error(_("split commit is empty")); + goto out; + } else if (oideq(&split_tree->object.oid, &original_commit_tree_oid)) { + ret = error(_("split commit tree matches original commit")); + goto out; + } + + /* We retain authorship of the original commit. */ + original_message = repo_logmsg_reencode(repo, original_commit, NULL, NULL); + ptr = find_commit_header(original_message, "author", &len); + if (ptr) + original_author = xmemdupz(ptr, len); + + ret = fill_commit_message(repo, &parent_tree_oid, &split_tree->object.oid, + "", "split-out", &split_message); + if (ret < 0) + goto out; + + ret = commit_tree(split_message.buf, split_message.len, &split_tree->object.oid, + original_commit->parents, &out[0], original_author, NULL); + if (ret < 0) { + ret = error(_("failed writing split-out commit")); + goto out; + } + + /* + * The second commit is much simpler to construct, as we can simply use + * the original commit details, except that we adjust its parent to be + * the newly split-out commit. + */ + find_commit_subject(original_message, &original_body); + first_commit = lookup_commit_reference(repo, &out[0]); + commit_list_append(first_commit, &parents); + + ret = commit_tree(original_body, strlen(original_body), &original_commit_tree_oid, + parents, &out[1], original_author, NULL); + if (ret < 0) { + ret = error(_("failed writing second commit")); + goto out; + } + + ret = 0; + +out: + if (index_file.len) + unlink(index_file.buf); + strbuf_release(&split_message); + strbuf_release(&index_file); + free_commit_list(parents); + free(original_author); + release_index(&index); + return ret; +} + +static int cmd_history_split(int argc, + const char **argv, + const char *prefix, + struct repository *repo) +{ + const char * const usage[] = { + GIT_HISTORY_SPLIT_USAGE, + NULL, + }; + struct option options[] = { + OPT_END(), + }; + struct oidmap rewritten_commits = OIDMAP_INIT; + struct commit *original_commit, *parent, *head; + struct strvec commits = STRVEC_INIT; + struct commit_list *from_list = NULL; + struct object_id split_commits[2]; + struct pathspec pathspec = { 0 }; + int ret; + + argc = parse_options(argc, argv, prefix, options, usage, 0); + if (argc < 1) { + ret = error(_("command expects a revision")); + goto out; + } + repo_config(repo, git_default_config, NULL); + + original_commit = lookup_commit_reference_by_name(argv[0]); + if (!original_commit) { + ret = error(_("commit to be split cannot be found: %s"), argv[0]); + goto out; + } + + parent = original_commit->parents ? original_commit->parents->item : NULL; + if (parent && repo_parse_commit(repo, parent)) { + ret = error(_("unable to parse commit %s"), + oid_to_hex(&parent->object.oid)); + goto out; + } + + head = lookup_commit_reference_by_name("HEAD"); + if (!head) { + ret = error(_("could not resolve HEAD to a commit")); + goto out; + } + + commit_list_append(original_commit, &from_list); + if (!repo_is_descendant_of(repo, head, from_list)) { + ret = error(_("split commit must be reachable from current HEAD commit")); + goto out; + } + + parse_pathspec(&pathspec, 0, + PATHSPEC_PREFER_FULL | PATHSPEC_SYMLINK_LEADING_PATH | PATHSPEC_PREFIX_ORIGIN, + prefix, argv + 1); + + /* + * Collect the list of commits that we'll have to reapply now already. + * This ensures that we'll abort early on in case the range of commits + * contains merges, which we do not yet handle. + */ + ret = collect_commits(repo, parent, head, &commits); + if (ret < 0) + goto out; + + /* + * Then we split up the commit and replace the original commit with the + * new ones. + */ + ret = split_commit(repo, original_commit, &pathspec, split_commits); + if (ret < 0) + goto out; + + replace_commits(&commits, &original_commit->object.oid, + split_commits, ARRAY_SIZE(split_commits)); + + ret = apply_commits(repo, &commits, parent, head, "split"); + if (ret < 0) + goto out; + + ret = 0; + +out: + oidmap_clear(&rewritten_commits, 0); + free_commit_list(from_list); + clear_pathspec(&pathspec); + strvec_clear(&commits); + return ret; +} + int cmd_history(int argc, const char **argv, const char *prefix, @@ -330,11 +546,13 @@ int cmd_history(int argc, { const char * const usage[] = { GIT_HISTORY_REWORD_USAGE, + GIT_HISTORY_SPLIT_USAGE, NULL, }; parse_opt_subcommand_fn *fn = NULL; struct option options[] = { OPT_SUBCOMMAND("reword", &fn, cmd_history_reword), + OPT_SUBCOMMAND("split", &fn, cmd_history_split), OPT_END(), }; |