worktree: add 'list' command
[gitweb.git] / builtin / pull.c
index 647bcb9f3a44b0cd37f98110820c0f5cd42a2c7f..a39bb0a11f72982f51222cdcf19d1010367c908f 100644 (file)
 #include "run-command.h"
 #include "sha1-array.h"
 #include "remote.h"
+#include "dir.h"
+#include "refs.h"
+#include "revision.h"
+#include "tempfile.h"
+#include "lockfile.h"
+
+enum rebase_type {
+       REBASE_INVALID = -1,
+       REBASE_FALSE = 0,
+       REBASE_TRUE,
+       REBASE_PRESERVE
+};
+
+/**
+ * Parses the value of --rebase. If value is a false value, returns
+ * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
+ * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
+ * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
+ */
+static enum rebase_type parse_config_rebase(const char *key, const char *value,
+               int fatal)
+{
+       int v = git_config_maybe_bool("pull.rebase", value);
+
+       if (!v)
+               return REBASE_FALSE;
+       else if (v > 0)
+               return REBASE_TRUE;
+       else if (!strcmp(value, "preserve"))
+               return REBASE_PRESERVE;
+
+       if (fatal)
+               die(_("Invalid value for %s: %s"), key, value);
+       else
+               error(_("Invalid value for %s: %s"), key, value);
+
+       return REBASE_INVALID;
+}
+
+/**
+ * Callback for --rebase, which parses arg with parse_config_rebase().
+ */
+static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
+{
+       enum rebase_type *value = opt->value;
+
+       if (arg)
+               *value = parse_config_rebase("--rebase", arg, 0);
+       else
+               *value = unset ? REBASE_FALSE : REBASE_TRUE;
+       return *value == REBASE_INVALID ? -1 : 0;
+}
 
 static const char * const pull_usage[] = {
        N_("git pull [options] [<repository> [<refspec>...]]"),
@@ -22,7 +74,8 @@ static const char * const pull_usage[] = {
 static int opt_verbosity;
 static char *opt_progress;
 
-/* Options passed to git-merge */
+/* Options passed to git-merge or git-rebase */
+static enum rebase_type opt_rebase = -1;
 static char *opt_diffstat;
 static char *opt_log;
 static char *opt_squash;
@@ -56,8 +109,12 @@ static struct option pull_options[] = {
                N_("force progress reporting"),
                PARSE_OPT_NOARG),
 
-       /* Options passed to git-merge */
+       /* Options passed to git-merge or git-rebase */
        OPT_GROUP(N_("Options related to merging")),
+       { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
+         "false|true|preserve",
+         N_("incorporate changes by rebasing rather than merging"),
+         PARSE_OPT_OPTARG, parse_opt_rebase },
        OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
                N_("do not show a diffstat at the end of the merge"),
                PARSE_OPT_NOARG | PARSE_OPT_NONEG),
@@ -166,6 +223,148 @@ static void argv_push_force(struct argv_array *arr)
                argv_array_push(arr, "-f");
 }
 
+/**
+ * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
+ */
+static void set_reflog_message(int argc, const char **argv)
+{
+       int i;
+       struct strbuf msg = STRBUF_INIT;
+
+       for (i = 0; i < argc; i++) {
+               if (i)
+                       strbuf_addch(&msg, ' ');
+               strbuf_addstr(&msg, argv[i]);
+       }
+
+       setenv("GIT_REFLOG_ACTION", msg.buf, 0);
+
+       strbuf_release(&msg);
+}
+
+/**
+ * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
+ * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
+ * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
+ * error.
+ */
+static const char *config_get_ff(void)
+{
+       const char *value;
+
+       if (git_config_get_value("pull.ff", &value))
+               return NULL;
+
+       switch (git_config_maybe_bool("pull.ff", value)) {
+       case 0:
+               return "--no-ff";
+       case 1:
+               return "--ff";
+       }
+
+       if (!strcmp(value, "only"))
+               return "--ff-only";
+
+       die(_("Invalid value for pull.ff: %s"), value);
+}
+
+/**
+ * Returns the default configured value for --rebase. It first looks for the
+ * value of "branch.$curr_branch.rebase", where $curr_branch is the current
+ * branch, and if HEAD is detached or the configuration key does not exist,
+ * looks for the value of "pull.rebase". If both configuration keys do not
+ * exist, returns REBASE_FALSE.
+ */
+static enum rebase_type config_get_rebase(void)
+{
+       struct branch *curr_branch = branch_get("HEAD");
+       const char *value;
+
+       if (curr_branch) {
+               char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
+
+               if (!git_config_get_value(key, &value)) {
+                       enum rebase_type ret = parse_config_rebase(key, value, 1);
+                       free(key);
+                       return ret;
+               }
+
+               free(key);
+       }
+
+       if (!git_config_get_value("pull.rebase", &value))
+               return parse_config_rebase("pull.rebase", value, 1);
+
+       return REBASE_FALSE;
+}
+
+/**
+ * Returns 1 if there are unstaged changes, 0 otherwise.
+ */
+static int has_unstaged_changes(const char *prefix)
+{
+       struct rev_info rev_info;
+       int result;
+
+       init_revisions(&rev_info, prefix);
+       DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
+       DIFF_OPT_SET(&rev_info.diffopt, QUICK);
+       diff_setup_done(&rev_info.diffopt);
+       result = run_diff_files(&rev_info, 0);
+       return diff_result_code(&rev_info.diffopt, result);
+}
+
+/**
+ * Returns 1 if there are uncommitted changes, 0 otherwise.
+ */
+static int has_uncommitted_changes(const char *prefix)
+{
+       struct rev_info rev_info;
+       int result;
+
+       if (is_cache_unborn())
+               return 0;
+
+       init_revisions(&rev_info, prefix);
+       DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
+       DIFF_OPT_SET(&rev_info.diffopt, QUICK);
+       add_head_to_pending(&rev_info);
+       diff_setup_done(&rev_info.diffopt);
+       result = run_diff_index(&rev_info, 1);
+       return diff_result_code(&rev_info.diffopt, result);
+}
+
+/**
+ * If the work tree has unstaged or uncommitted changes, dies with the
+ * appropriate message.
+ */
+static void die_on_unclean_work_tree(const char *prefix)
+{
+       struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file));
+       int do_die = 0;
+
+       hold_locked_index(lock_file, 0);
+       refresh_cache(REFRESH_QUIET);
+       update_index_if_able(&the_index, lock_file);
+       rollback_lock_file(lock_file);
+
+       if (has_unstaged_changes(prefix)) {
+               error(_("Cannot pull with rebase: You have unstaged changes."));
+               do_die = 1;
+       }
+
+       if (has_uncommitted_changes(prefix)) {
+               if (do_die)
+                       error(_("Additionally, your index contains uncommitted changes."));
+               else
+                       error(_("Cannot pull with rebase: Your index contains uncommitted changes."));
+               do_die = 1;
+       }
+
+       if (do_die)
+               exit(1);
+}
+
 /**
  * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
  * into merge_heads.
@@ -233,7 +432,10 @@ static void NORETURN die_no_merge_candidates(const char *repo, const char **refs
        const char *remote = curr_branch ? curr_branch->remote_name : NULL;
 
        if (*refspecs) {
-               fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
+               if (opt_rebase)
+                       fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
+               else
+                       fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
                fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
                                        "matches on the remote end."));
        } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
@@ -243,7 +445,10 @@ static void NORETURN die_no_merge_candidates(const char *repo, const char **refs
                        repo);
        } else if (!curr_branch) {
                fprintf_ln(stderr, _("You are not currently on a branch."));
-               fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
+               if (opt_rebase)
+                       fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
+               else
+                       fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
                fprintf_ln(stderr, _("See git-pull(1) for details."));
                fprintf(stderr, "\n");
                fprintf_ln(stderr, "    git pull <remote> <branch>");
@@ -255,7 +460,10 @@ static void NORETURN die_no_merge_candidates(const char *repo, const char **refs
                        remote_name = "<remote>";
 
                fprintf_ln(stderr, _("There is no tracking information for the current branch."));
-               fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
+               if (opt_rebase)
+                       fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
+               else
+                       fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
                fprintf_ln(stderr, _("See git-pull(1) for details."));
                fprintf(stderr, "\n");
                fprintf_ln(stderr, "    git pull <remote> <branch>");
@@ -340,6 +548,27 @@ static int run_fetch(const char *repo, const char **refspecs)
        return ret;
 }
 
+/**
+ * "Pulls into void" by branching off merge_head.
+ */
+static int pull_into_void(const unsigned char *merge_head,
+               const unsigned char *curr_head)
+{
+       /*
+        * Two-way merge: we treat the index as based on an empty tree,
+        * and try to fast-forward to HEAD. This ensures we will not lose
+        * index/worktree changes that the user already made on the unborn
+        * branch.
+        */
+       if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0))
+               return 1;
+
+       if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
+               return 1;
+
+       return 0;
+}
+
 /**
  * Runs git-merge, returning its exit status.
  */
@@ -381,32 +610,278 @@ static int run_merge(void)
        return ret;
 }
 
+/**
+ * Returns remote's upstream branch for the current branch. If remote is NULL,
+ * the current branch's configured default remote is used. Returns NULL if
+ * `remote` does not name a valid remote, HEAD does not point to a branch,
+ * remote is not the branch's configured remote or the branch does not have any
+ * configured upstream branch.
+ */
+static const char *get_upstream_branch(const char *remote)
+{
+       struct remote *rm;
+       struct branch *curr_branch;
+       const char *curr_branch_remote;
+
+       rm = remote_get(remote);
+       if (!rm)
+               return NULL;
+
+       curr_branch = branch_get("HEAD");
+       if (!curr_branch)
+               return NULL;
+
+       curr_branch_remote = remote_for_branch(curr_branch, NULL);
+       assert(curr_branch_remote);
+
+       if (strcmp(curr_branch_remote, rm->name))
+               return NULL;
+
+       return branch_get_upstream(curr_branch, NULL);
+}
+
+/**
+ * Derives the remote tracking branch from the remote and refspec.
+ *
+ * FIXME: The current implementation assumes the default mapping of
+ * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
+ */
+static const char *get_tracking_branch(const char *remote, const char *refspec)
+{
+       struct refspec *spec;
+       const char *spec_src;
+       const char *merge_branch;
+
+       spec = parse_fetch_refspec(1, &refspec);
+       spec_src = spec->src;
+       if (!*spec_src || !strcmp(spec_src, "HEAD"))
+               spec_src = "HEAD";
+       else if (skip_prefix(spec_src, "heads/", &spec_src))
+               ;
+       else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
+               ;
+       else if (starts_with(spec_src, "refs/") ||
+               starts_with(spec_src, "tags/") ||
+               starts_with(spec_src, "remotes/"))
+               spec_src = "";
+
+       if (*spec_src) {
+               if (!strcmp(remote, "."))
+                       merge_branch = mkpath("refs/heads/%s", spec_src);
+               else
+                       merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
+       } else
+               merge_branch = NULL;
+
+       free_refspec(1, spec);
+       return merge_branch;
+}
+
+/**
+ * Given the repo and refspecs, sets fork_point to the point at which the
+ * current branch forked from its remote tracking branch. Returns 0 on success,
+ * -1 on failure.
+ */
+static int get_rebase_fork_point(unsigned char *fork_point, const char *repo,
+               const char *refspec)
+{
+       int ret;
+       struct branch *curr_branch;
+       const char *remote_branch;
+       struct child_process cp = CHILD_PROCESS_INIT;
+       struct strbuf sb = STRBUF_INIT;
+
+       curr_branch = branch_get("HEAD");
+       if (!curr_branch)
+               return -1;
+
+       if (refspec)
+               remote_branch = get_tracking_branch(repo, refspec);
+       else
+               remote_branch = get_upstream_branch(repo);
+
+       if (!remote_branch)
+               return -1;
+
+       argv_array_pushl(&cp.args, "merge-base", "--fork-point",
+                       remote_branch, curr_branch->name, NULL);
+       cp.no_stdin = 1;
+       cp.no_stderr = 1;
+       cp.git_cmd = 1;
+
+       ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ);
+       if (ret)
+               goto cleanup;
+
+       ret = get_sha1_hex(sb.buf, fork_point);
+       if (ret)
+               goto cleanup;
+
+cleanup:
+       strbuf_release(&sb);
+       return ret ? -1 : 0;
+}
+
+/**
+ * Sets merge_base to the octopus merge base of curr_head, merge_head and
+ * fork_point. Returns 0 if a merge base is found, 1 otherwise.
+ */
+static int get_octopus_merge_base(unsigned char *merge_base,
+               const unsigned char *curr_head,
+               const unsigned char *merge_head,
+               const unsigned char *fork_point)
+{
+       struct commit_list *revs = NULL, *result;
+
+       commit_list_insert(lookup_commit_reference(curr_head), &revs);
+       commit_list_insert(lookup_commit_reference(merge_head), &revs);
+       if (!is_null_sha1(fork_point))
+               commit_list_insert(lookup_commit_reference(fork_point), &revs);
+
+       result = reduce_heads(get_octopus_merge_bases(revs));
+       free_commit_list(revs);
+       if (!result)
+               return 1;
+
+       hashcpy(merge_base, result->item->object.sha1);
+       return 0;
+}
+
+/**
+ * Given the current HEAD SHA1, the merge head returned from git-fetch and the
+ * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
+ * appropriate arguments and returns its exit status.
+ */
+static int run_rebase(const unsigned char *curr_head,
+               const unsigned char *merge_head,
+               const unsigned char *fork_point)
+{
+       int ret;
+       unsigned char oct_merge_base[GIT_SHA1_RAWSZ];
+       struct argv_array args = ARGV_ARRAY_INIT;
+
+       if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point))
+               if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point))
+                       fork_point = NULL;
+
+       argv_array_push(&args, "rebase");
+
+       /* Shared options */
+       argv_push_verbosity(&args);
+
+       /* Options passed to git-rebase */
+       if (opt_rebase == REBASE_PRESERVE)
+               argv_array_push(&args, "--preserve-merges");
+       if (opt_diffstat)
+               argv_array_push(&args, opt_diffstat);
+       argv_array_pushv(&args, opt_strategies.argv);
+       argv_array_pushv(&args, opt_strategy_opts.argv);
+       if (opt_gpg_sign)
+               argv_array_push(&args, opt_gpg_sign);
+
+       argv_array_push(&args, "--onto");
+       argv_array_push(&args, sha1_to_hex(merge_head));
+
+       if (fork_point && !is_null_sha1(fork_point))
+               argv_array_push(&args, sha1_to_hex(fork_point));
+       else
+               argv_array_push(&args, sha1_to_hex(merge_head));
+
+       ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
+       argv_array_clear(&args);
+       return ret;
+}
+
 int cmd_pull(int argc, const char **argv, const char *prefix)
 {
        const char *repo, **refspecs;
        struct sha1_array merge_heads = SHA1_ARRAY_INIT;
+       unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
+       unsigned char rebase_fork_point[GIT_SHA1_RAWSZ];
 
-       if (!getenv("_GIT_USE_BUILTIN_PULL")) {
-               const char *path = mkpath("%s/git-pull", git_exec_path());
-
-               if (sane_execvp(path, (char **)argv) < 0)
-                       die_errno("could not exec %s", path);
-       }
+       if (!getenv("GIT_REFLOG_ACTION"))
+               set_reflog_message(argc, argv);
 
        argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 
        parse_repo_refspecs(argc, argv, &repo, &refspecs);
 
+       if (!opt_ff)
+               opt_ff = xstrdup_or_null(config_get_ff());
+
+       if (opt_rebase < 0)
+               opt_rebase = config_get_rebase();
+
+       git_config(git_default_config, NULL);
+
+       if (read_cache_unmerged())
+               die_resolve_conflict("Pull");
+
+       if (file_exists(git_path("MERGE_HEAD")))
+               die_conclude_merge();
+
+       if (get_sha1("HEAD", orig_head))
+               hashclr(orig_head);
+
+       if (opt_rebase) {
+               int autostash = 0;
+
+               if (is_null_sha1(orig_head) && !is_cache_unborn())
+                       die(_("Updating an unborn branch with changes added to the index."));
+
+               git_config_get_bool("rebase.autostash", &autostash);
+               if (!autostash)
+                       die_on_unclean_work_tree(prefix);
+
+               if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
+                       hashclr(rebase_fork_point);
+       }
+
        if (run_fetch(repo, refspecs))
                return 1;
 
        if (opt_dry_run)
                return 0;
 
+       if (get_sha1("HEAD", curr_head))
+               hashclr(curr_head);
+
+       if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
+                       hashcmp(orig_head, curr_head)) {
+               /*
+                * The fetch involved updating the current branch.
+                *
+                * The working tree and the index file are still based on
+                * orig_head commit, but we are merging into curr_head.
+                * Update the working tree to match curr_head.
+                */
+
+               warning(_("fetch updated the current branch head.\n"
+                       "fast-forwarding your working tree from\n"
+                       "commit %s."), sha1_to_hex(orig_head));
+
+               if (checkout_fast_forward(orig_head, curr_head, 0))
+                       die(_("Cannot fast-forward your working tree.\n"
+                               "After making sure that you saved anything precious from\n"
+                               "$ git diff %s\n"
+                               "output, run\n"
+                               "$ git reset --hard\n"
+                               "to recover."), sha1_to_hex(orig_head));
+       }
+
        get_merge_heads(&merge_heads);
 
        if (!merge_heads.nr)
                die_no_merge_candidates(repo, refspecs);
 
-       return run_merge();
+       if (is_null_sha1(orig_head)) {
+               if (merge_heads.nr > 1)
+                       die(_("Cannot merge multiple branches into empty head."));
+               return pull_into_void(*merge_heads.sha1, curr_head);
+       } else if (opt_rebase) {
+               if (merge_heads.nr > 1)
+                       die(_("Cannot rebase onto multiple branches."));
+               return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
+       } else
+               return run_merge();
 }