checkout: don't require a work tree when checking out into a new one
[gitweb.git] / builtin / checkout.c
index 797e14df419aec20f3b9336014973d634fcaaaab..8c5276cf443f5d1e84cd5fd34e5f899afd3e58b6 100644 (file)
@@ -20,6 +20,7 @@
 #include "resolve-undo.h"
 #include "submodule.h"
 #include "argv-array.h"
+#include "sigchain.h"
 
 static const char * const checkout_usage[] = {
        N_("git checkout [options] <branch>"),
@@ -430,6 +431,11 @@ struct branch_info {
        const char *name; /* The short name used */
        const char *path; /* The full name of a real branch */
        struct commit *commit; /* The named commit */
+       /*
+        * if not null the branch is detached because it's already
+        * checked out in this checkout
+        */
+       char *checkout;
 };
 
 static void setup_branch_path(struct branch_info *branch)
@@ -818,6 +824,35 @@ static int switch_branches(const struct checkout_opts *opts,
        return ret || writeout_error;
 }
 
+static char *junk_work_tree;
+static char *junk_git_dir;
+static int is_junk;
+static pid_t junk_pid;
+
+static void remove_junk(void)
+{
+       struct strbuf sb = STRBUF_INIT;
+       if (!is_junk || getpid() != junk_pid)
+               return;
+       if (junk_git_dir) {
+               strbuf_addstr(&sb, junk_git_dir);
+               remove_dir_recursively(&sb, 0);
+               strbuf_reset(&sb);
+       }
+       if (junk_work_tree) {
+               strbuf_addstr(&sb, junk_work_tree);
+               remove_dir_recursively(&sb, 0);
+       }
+       strbuf_release(&sb);
+}
+
+static void remove_junk_on_signal(int signo)
+{
+       remove_junk();
+       sigchain_pop(signo);
+       raise(signo);
+}
+
 static int prepare_linked_checkout(const struct checkout_opts *opts,
                                   struct branch_info *new)
 {
@@ -826,7 +861,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
        const char *path = opts->new_worktree, *name;
        struct stat st;
        struct child_process cp;
-       int counter = 0, len;
+       int counter = 0, len, ret;
 
        if (!new->commit)
                die(_("no branch specified"));
@@ -854,14 +889,32 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
                strbuf_addf(&sb_repo, "%d", counter);
        }
        name = strrchr(sb_repo.buf, '/') + 1;
+
+       junk_pid = getpid();
+       atexit(remove_junk);
+       sigchain_push_common(remove_junk_on_signal);
+
        if (mkdir(sb_repo.buf, 0777))
                die_errno(_("could not create directory of '%s'"), sb_repo.buf);
+       junk_git_dir = xstrdup(sb_repo.buf);
+       is_junk = 1;
+
+       /*
+        * lock the incomplete repo so prune won't delete it, unlock
+        * after the preparation is over.
+        */
+       strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+       write_file(sb.buf, 1, "initializing\n");
 
        strbuf_addf(&sb_git, "%s/.git", path);
        if (safe_create_leading_directories_const(sb_git.buf))
                die_errno(_("could not create leading directories of '%s'"),
                          sb_git.buf);
+       junk_work_tree = xstrdup(path);
 
+       strbuf_reset(&sb);
+       strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
+       write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
        write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
                   real_path(get_git_common_dir()), name);
        /*
@@ -870,6 +923,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
         * value would do because this value will be ignored and
         * replaced at the next (real) checkout.
         */
+       strbuf_reset(&sb);
        strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
        write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1));
        strbuf_reset(&sb);
@@ -885,7 +939,21 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
        memset(&cp, 0, sizeof(cp));
        cp.git_cmd = 1;
        cp.argv = opts->saved_argv;
-       return run_command(&cp);
+       ret = run_command(&cp);
+       if (!ret) {
+               is_junk = 0;
+               free(junk_work_tree);
+               free(junk_git_dir);
+               junk_work_tree = NULL;
+               junk_git_dir = NULL;
+       }
+       strbuf_reset(&sb);
+       strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+       unlink_or_warn(sb.buf);
+       strbuf_release(&sb);
+       strbuf_release(&sb_repo);
+       strbuf_release(&sb_git);
+       return ret;
 }
 
 static int git_checkout_config(const char *var, const char *value, void *cb)
@@ -943,12 +1011,78 @@ static const char *unique_tracking_name(const char *name, unsigned char *sha1)
        return NULL;
 }
 
+static void check_linked_checkout(struct branch_info *new, const char *id)
+{
+       struct strbuf sb = STRBUF_INIT;
+       struct strbuf path = STRBUF_INIT;
+       struct strbuf gitdir = STRBUF_INIT;
+       const char *start, *end;
+
+       if (id)
+               strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+       else
+               strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+
+       if (strbuf_read_file(&sb, path.buf, 0) < 0 ||
+           !skip_prefix(sb.buf, "ref:", &start))
+               goto done;
+       while (isspace(*start))
+               start++;
+       end = start;
+       while (*end && !isspace(*end))
+               end++;
+       if (strncmp(start, new->path, end - start) || new->path[end - start] != '\0')
+               goto done;
+       if (id) {
+               strbuf_reset(&path);
+               strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
+               if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
+                       goto done;
+               strbuf_rtrim(&gitdir);
+       } else
+               strbuf_addstr(&gitdir, get_git_common_dir());
+       die(_("'%s' is already checked out at '%s'"), new->name, gitdir.buf);
+done:
+       strbuf_release(&path);
+       strbuf_release(&sb);
+       strbuf_release(&gitdir);
+}
+
+static void check_linked_checkouts(struct branch_info *new)
+{
+       struct strbuf path = STRBUF_INIT;
+       DIR *dir;
+       struct dirent *d;
+
+       strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+       if ((dir = opendir(path.buf)) == NULL) {
+               strbuf_release(&path);
+               return;
+       }
+
+       /*
+        * $GIT_COMMON_DIR/HEAD is practically outside
+        * $GIT_DIR so resolve_ref_unsafe() won't work (it
+        * uses git_path). Parse the ref ourselves.
+        */
+       check_linked_checkout(new, NULL);
+
+       while ((d = readdir(dir)) != NULL) {
+               if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+                       continue;
+               check_linked_checkout(new, d->d_name);
+       }
+       strbuf_release(&path);
+       closedir(dir);
+}
+
 static int parse_branchname_arg(int argc, const char **argv,
                                int dwim_new_local_branch_ok,
                                struct branch_info *new,
                                struct tree **source_tree,
                                unsigned char rev[20],
-                               const char **new_branch)
+                               const char **new_branch,
+                               int force_detach)
 {
        int argcount = 0;
        unsigned char branch_rev[20];
@@ -1070,6 +1204,16 @@ static int parse_branchname_arg(int argc, const char **argv,
        else
                new->path = NULL; /* not an existing branch */
 
+       if (new->path && !force_detach && !*new_branch) {
+               unsigned char sha1[20];
+               int flag;
+               char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
+               if (head_ref &&
+                   (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
+                       check_linked_checkouts(new);
+               free(head_ref);
+       }
+
        new->commit = lookup_commit_reference_gently(rev, 1);
        if (!new->commit) {
                /* not a commit */
@@ -1220,6 +1364,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        if (opts.new_worktree_mode)
                opts.new_worktree = NULL;
 
+       if (!opts.new_worktree)
+               setup_work_tree();
+
        if (conflict_style) {
                opts.merge = 1; /* implied */
                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
@@ -1274,7 +1421,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                        !opts.new_branch;
                int n = parse_branchname_arg(argc, argv, dwim_ok,
                                             &new, &opts.source_tree,
-                                            rev, &opts.new_branch);
+                                            rev, &opts.new_branch,
+                                            opts.force_detach);
                argv += n;
                argc -= n;
        }