worktree: add: suppress auto-vivication with --detach and no <branch>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index b4decd5b19c6ec9399f80c7a063343331fe8fd38..4ae895ca94dbcd39b6509efa95f311e68e88ff93 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -19,7 +19,6 @@
 #include "ll-merge.h"
 #include "resolve-undo.h"
 #include "submodule.h"
-#include "argv-array.h"
 
 static const char * const checkout_usage[] = {
        N_("git checkout [options] <branch>"),
@@ -36,6 +35,7 @@ struct checkout_opts {
        int writeout_stage;
        int overwrite_ignore;
        int ignore_skipworktree;
+       int ignore_other_worktrees;
 
        const char *new_branch;
        const char *new_branch_force;
@@ -48,6 +48,8 @@ struct checkout_opts {
        const char *prefix;
        struct pathspec pathspec;
        struct tree *source_tree;
+
+       int new_worktree_mode;
 };
 
 static int post_checkout_hook(struct commit *old, struct commit *new,
@@ -355,7 +357,7 @@ static int checkout_paths(const struct checkout_opts *opts,
        if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
                die(_("unable to write new index file"));
 
-       read_ref_full("HEAD", rev, 0, &flag);
+       read_ref_full("HEAD", 0, rev, &flag);
        head = lookup_commit_reference_gently(rev, 1);
 
        errs |= post_checkout_hook(head, head, 0);
@@ -423,6 +425,11 @@ 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)
@@ -484,7 +491,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
                        topts.dir->flags |= DIR_SHOW_IGNORED;
                        setup_standard_excludes(topts.dir);
                }
-               tree = parse_tree_indirect(old->commit ?
+               tree = parse_tree_indirect(old->commit && !opts->new_worktree_mode ?
                                           old->commit->object.sha1 :
                                           EMPTY_TREE_SHA1_BIN);
                init_tree_desc(&trees[0], tree->buffer, tree->size);
@@ -588,18 +595,21 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
                if (opts->new_orphan_branch) {
                        if (opts->new_branch_log && !log_all_ref_updates) {
                                int temp;
-                               char log_file[PATH_MAX];
-                               char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+                               struct strbuf log_file = STRBUF_INIT;
+                               int ret;
+                               const char *ref_name;
 
+                               ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
                                temp = log_all_ref_updates;
                                log_all_ref_updates = 1;
-                               if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
+                               ret = log_ref_setup(ref_name, &log_file);
+                               log_all_ref_updates = temp;
+                               strbuf_release(&log_file);
+                               if (ret) {
                                        fprintf(stderr, _("Can not do reflog for '%s'\n"),
                                            opts->new_orphan_branch);
-                                       log_all_ref_updates = temp;
                                        return;
                                }
-                               log_all_ref_updates = temp;
                        }
                }
                else
@@ -775,7 +785,7 @@ static int switch_branches(const struct checkout_opts *opts,
        unsigned char rev[20];
        int flag, writeout_error = 0;
        memset(&old, 0, sizeof(old));
-       old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
+       old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
        old.commit = lookup_commit_reference_gently(rev, 1);
        if (!(flag & REF_ISSYMREF))
                old.path = NULL;
@@ -797,7 +807,8 @@ static int switch_branches(const struct checkout_opts *opts,
                return ret;
        }
 
-       if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
+       if (!opts->quiet && !old.path && old.commit &&
+           new->commit != old.commit && !opts->new_worktree_mode)
                orphaned_commit_warning(old.commit, new->commit);
 
        update_refs_for_switch(opts, &old, new);
@@ -865,10 +876,11 @@ static const char *unique_tracking_name(const char *name, unsigned char *sha1)
 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)
+                               struct checkout_opts *opts,
+                               unsigned char rev[20])
 {
+       struct tree **source_tree = &opts->source_tree;
+       const char **new_branch = &opts->new_branch;
        int argcount = 0;
        unsigned char branch_rev[20];
        const char *arg;
@@ -1068,11 +1080,22 @@ static int checkout_branch(struct checkout_opts *opts,
                die(_("Cannot switch branch to a non-commit '%s'"),
                    new->name);
 
+       if (new->path && !opts->force_detach && !opts->new_branch &&
+           !opts->ignore_other_worktrees) {
+               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)))
+                       die_if_checked_out(new->path);
+               free(head_ref);
+       }
+
        if (!new->commit && opts->new_branch) {
                unsigned char rev[20];
                int flag;
 
-               if (!read_ref_full("HEAD", rev, 0, &flag) &&
+               if (!read_ref_full("HEAD", 0, rev, &flag) &&
                    (flag & REF_ISSYMREF) && is_null_sha1(rev))
                        return switch_unborn_to_new_branch(opts);
        }
@@ -1110,6 +1133,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                         N_("do not limit pathspecs to sparse entries only")),
                OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
                                N_("second guess 'git checkout no-such-branch'")),
+               OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
+                        N_("do not check if another worktree is holding the given ref")),
                OPT_END(),
        };
 
@@ -1126,6 +1151,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        argc = parse_options(argc, argv, prefix, options, checkout_usage,
                             PARSE_OPT_KEEP_DASHDASH);
 
+       opts.new_worktree_mode = getenv("GIT_CHECKOUT_NEW_WORKTREE") != NULL;
+
        if (conflict_style) {
                opts.merge = 1; /* implied */
                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
@@ -1179,8 +1206,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                        opts.track == BRANCH_TRACK_UNSPECIFIED &&
                        !opts.new_branch;
                int n = parse_branchname_arg(argc, argv, dwim_ok,
-                                            &new, &opts.source_tree,
-                                            rev, &opts.new_branch);
+                                            &new, &opts, rev);
                argv += n;
                argc -= n;
        }