Merge branch 'em/checkout-orphan'

* em/checkout-orphan:
  git checkout: create unparented branch by --orphan

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 37c1810e3fc8424868333a22094107e99764fc37..4505eb6d84990944009d0b5e560de4bd4d2022e8 100644 (file)
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git checkout' [-q] [-f] [-m] [<branch>]
-'git checkout' [-q] [-f] [-m] [-b <new_branch>] [<start_point>]
+'git checkout' [-q] [-f] [-m] [[-b|--orphan] <new_branch>] [<start_point>]
 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
 'git checkout' --patch [<tree-ish>] [--] [<paths>...]
 
@@ -90,6 +90,24 @@ explicitly give a name with '-b' in such a case.
        Create the new branch's reflog; see linkgit:git-branch[1] for
        details.
 
+--orphan::
+       Create a new branch named <new_branch>, unparented to any other
+       branch.  The new branch you switch to does not have any commit
+       and after the first one it will become the root of a new history
+       completely unconnected from all the other branches.
++
+When you use "--orphan", the index and the working tree are kept intact.
+This allows you to start a new history that records set of paths similar
+to that of the start-point commit, which is useful when you want to keep
+different branches for different audiences you are working to like when
+you have an open source and commercial versions of a software, for example.
++
+If you want to start a disconnected history that records set of paths
+totally different from the original branch, you may want to first clear
+the index and the working tree, by running "git rm -rf ." from the
+top-level of the working tree, before preparing your files (by copying
+from elsewhere, extracting a tarball, etc.) in the working tree.
+
 -m::
 --merge::
        When switching branches,

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 88b1f43e05e64f0e8dcd6dd0461bbebd6fab1e25..c3825219c1efbd4939af6d18bcad6efcfa74f406 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -33,6 +33,7 @@ struct checkout_opts {
        int writeout_error;
 
        const char *new_branch;
+       const char *new_orphan_branch;
        int new_branch_log;
        enum branch_track track;
 };
@@ -492,8 +493,9 @@ static void update_refs_for_switch(struct checkout_opts *opts,
        struct strbuf msg = STRBUF_INIT;
        const char *old_desc;
        if (opts->new_branch) {
-               create_branch(old->name, opts->new_branch, new->name, 0,
-                             opts->new_branch_log, opts->track);
+               if (!opts->new_orphan_branch)
+                       create_branch(old->name, opts->new_branch, new->name, 0,
+                                     opts->new_branch_log, opts->track);
                new->name = opts->new_branch;
                setup_branch_path(new);
        }
@@ -633,6 +635,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
                OPT_SET_INT('t', "track",  &opts.track, "track",
                        BRANCH_TRACK_EXPLICIT),
+               OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
                OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
                            2),
                OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
@@ -678,6 +681,14 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                opts.new_branch = argv0 + 1;
        }
 
+       if (opts.new_orphan_branch) {
+               if (opts.new_branch)
+                       die("--orphan and -b are mutually exclusive");
+               if (opts.track > 0 || opts.new_branch_log)
+                       die("--orphan cannot be used with -t or -l");
+               opts.new_branch = opts.new_orphan_branch;
+       }
+
        if (conflict_style) {
                opts.merge = 1; /* implied */
                git_xmerge_config("merge.conflictstyle", conflict_style, NULL);

diff --git a/t/t2017-checkout-orphan.sh b/t/t2017-checkout-orphan.sh
new file mode 100755 (executable)
index 0000000..a8297c6
--- /dev/null
+++ b/t/t2017-checkout-orphan.sh
@@ -0,0 +1,90 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Erick Mattos
+#
+
+test_description='git checkout --orphan
+
+Main Tests for --orphan functionality.'
+
+. ./test-lib.sh
+
+TEST_FILE=foo
+
+test_expect_success 'Setup' '
+       echo "Initial" >"$TEST_FILE" &&
+       git add "$TEST_FILE" &&
+       git commit -m "First Commit"
+       test_tick &&
+       echo "State 1" >>"$TEST_FILE" &&
+       git add "$TEST_FILE" &&
+       test_tick &&
+       git commit -m "Second Commit"
+'
+
+test_expect_success '--orphan creates a new orphan branch from HEAD' '
+       git checkout --orphan alpha &&
+       test_must_fail git rev-parse --verify HEAD &&
+       test "refs/heads/alpha" = "$(git symbolic-ref HEAD)" &&
+       test_tick &&
+       git commit -m "Third Commit" &&
+       test_must_fail git rev-parse --verify HEAD^ &&
+       git diff-tree --quiet master alpha
+'
+
+test_expect_success '--orphan creates a new orphan branch from <start_point>' '
+       git checkout master &&
+       git checkout --orphan beta master^ &&
+       test_must_fail git rev-parse --verify HEAD &&
+       test "refs/heads/beta" = "$(git symbolic-ref HEAD)" &&
+       test_tick &&
+       git commit -m "Fourth Commit" &&
+       test_must_fail git rev-parse --verify HEAD^ &&
+       git diff-tree --quiet master^ beta
+'
+
+test_expect_success '--orphan must be rejected with -b' '
+       git checkout master &&
+       test_must_fail git checkout --orphan new -b newer &&
+       test refs/heads/master = "$(git symbolic-ref HEAD)"
+'
+
+test_expect_success '--orphan is rejected with an existing name' '
+       git checkout master &&
+       test_must_fail git checkout --orphan master &&
+       test refs/heads/master = "$(git symbolic-ref HEAD)"
+'
+
+test_expect_success '--orphan refuses to switch if a merge is needed' '
+       git checkout master &&
+       git reset --hard &&
+       echo local >>"$TEST_FILE" &&
+       cat "$TEST_FILE" >"$TEST_FILE.saved" &&
+       test_must_fail git checkout --orphan gamma master^ &&
+       test refs/heads/master = "$(git symbolic-ref HEAD)" &&
+       test_cmp "$TEST_FILE" "$TEST_FILE.saved" &&
+       git diff-index --quiet --cached HEAD &&
+       git reset --hard
+'
+
+test_expect_success '--orphan does not mix well with -t' '
+       git checkout master &&
+       test_must_fail git checkout -t master --orphan gamma &&
+       test refs/heads/master = "$(git symbolic-ref HEAD)"
+'
+
+test_expect_success '--orphan ignores branch.autosetupmerge' '
+       git checkout -f master &&
+       git config branch.autosetupmerge always &&
+       git checkout --orphan delta &&
+       test -z "$(git config branch.delta.merge)" &&
+       test refs/heads/delta = "$(git symbolic-ref HEAD)" &&
+       test_must_fail git rev-parse --verify HEAD^
+'
+
+test_expect_success '--orphan does not mix well with -l' '
+       git checkout -f master &&
+       test_must_fail git checkout -l --orphan gamma
+'
+
+test_done