revert: write REVERT_HEAD pseudoref during conflicted revert

When conflicts are encountered while reverting a commit, it can be
handy to have the name of that commit easily available.  For example,
to produce a copy of the patch to refer to while resolving conflicts:

	$ git revert 2eceb2a8
	error: could not revert 2eceb2a8... awesome, buggy feature
	$ git show -R REVERT_HEAD >the-patch
	$ edit $(git diff --name-only)

Set a REVERT_HEAD pseudoref when "git revert" does not make a commit,
for cases like this.  This also makes it possible for scripts to
distinguish between a revert that encountered conflicts and other
sources of an unmerged index.

After successfully committing, resetting with "git reset", or moving
to another commit with "git checkout" or "git reset", the pseudoref is
no longer useful, so remove it.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/branch.c b/branch.c
index d8098762f62a9dfb991f64702d34047182cfa951..025a97be0281b9fd3ccff2b36c03495b005ac4fe 100644 (file)
--- a/branch.c
+++ b/branch.c
@@ -241,6 +241,7 @@ void create_branch(const char *head,
 void remove_branch_state(void)
 {
        unlink(git_path("CHERRY_PICK_HEAD"));
+       unlink(git_path("REVERT_HEAD"));
        unlink(git_path("MERGE_HEAD"));
        unlink(git_path("MERGE_RR"));
        unlink(git_path("MERGE_MSG"));

diff --git a/builtin/commit.c b/builtin/commit.c
index c46f2d18e10bcb3b1b458d4ae94d2d3522305632..8f2bebecf313a0e4b742f9327ec178c7e3547dd2 100644 (file)
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1514,6 +1514,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
        }
 
        unlink(git_path("CHERRY_PICK_HEAD"));
+       unlink(git_path("REVERT_HEAD"));
        unlink(git_path("MERGE_HEAD"));
        unlink(git_path("MERGE_MSG"));
        unlink(git_path("MERGE_MODE"));

diff --git a/builtin/revert.c b/builtin/revert.c
index 1d112e4ce435ba608c1ffbf9d916e739db8a8050..f5ba67a50578b257c713b0d69d5c022f4e5f483b 100644 (file)
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -289,7 +289,7 @@ static char *get_encoding(const char *message)
        return NULL;
 }
 
-static void write_cherry_pick_head(struct commit *commit)
+static void write_cherry_pick_head(struct commit *commit, const char *pseudoref)
 {
        const char *filename;
        int fd;
@@ -297,7 +297,7 @@ static void write_cherry_pick_head(struct commit *commit)
 
        strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
 
-       filename = git_path("CHERRY_PICK_HEAD");
+       filename = git_path(pseudoref);
        fd = open(filename, O_WRONLY | O_CREAT, 0666);
        if (fd < 0)
                die_errno(_("Could not open '%s' for writing"), filename);
@@ -597,7 +597,9 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
         * write it at all.
         */
        if (opts->action == CHERRY_PICK && !opts->no_commit && (res == 0 || res == 1))
-               write_cherry_pick_head(commit);
+               write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
+       if (opts->action == REVERT && ((opts->no_commit && res == 0) || res == 1))
+               write_cherry_pick_head(commit, "REVERT_HEAD");
 
        if (res) {
                error(opts->action == REVERT

diff --git a/t/t3507-cherry-pick-conflict.sh b/t/t3507-cherry-pick-conflict.sh
index cb45574a7b5cbdf6da58f609befc4a0bb396db2f..ee1659c17810d2c9ce7836582a80fd3d0d89ca24 100755 (executable)
--- a/t/t3507-cherry-pick-conflict.sh
+++ b/t/t3507-cherry-pick-conflict.sh
@@ -253,6 +253,60 @@ test_expect_success 'revert also handles conflicts sanely' '
        test_cmp expected actual
 '
 
+test_expect_success 'failed revert sets REVERT_HEAD' '
+       pristine_detach initial &&
+       test_must_fail git revert picked &&
+       test_cmp_rev picked REVERT_HEAD
+'
+
+test_expect_success 'successful revert does not set REVERT_HEAD' '
+       pristine_detach base &&
+       git revert base &&
+       test_must_fail git rev-parse --verify CHERRY_PICK_HEAD &&
+       test_must_fail git rev-parse --verify REVERT_HEAD
+'
+
+test_expect_success 'revert --no-commit sets REVERT_HEAD' '
+       pristine_detach base &&
+       git revert --no-commit base &&
+       test_must_fail git rev-parse --verify CHERRY_PICK_HEAD &&
+       test_cmp_rev base REVERT_HEAD
+'
+
+test_expect_success 'revert w/dirty tree does not set REVERT_HEAD' '
+       pristine_detach base &&
+       echo foo > foo &&
+       test_must_fail git revert base &&
+       test_must_fail git rev-parse --verify CHERRY_PICK_HEAD &&
+       test_must_fail git rev-parse --verify REVERT_HEAD
+'
+
+test_expect_success 'GIT_CHERRY_PICK_HELP does not suppress REVERT_HEAD' '
+       pristine_detach initial &&
+       (
+               GIT_CHERRY_PICK_HELP="and then do something else" &&
+               GIT_REVERT_HELP="and then do something else, again" &&
+               export GIT_CHERRY_PICK_HELP GIT_REVERT_HELP &&
+               test_must_fail git revert picked
+       ) &&
+       test_must_fail git rev-parse --verify CHERRY_PICK_HEAD &&
+       test_cmp_rev picked REVERT_HEAD
+'
+
+test_expect_success 'git reset clears REVERT_HEAD' '
+       pristine_detach initial &&
+       test_must_fail git revert picked &&
+       git reset &&
+       test_must_fail git rev-parse --verify REVERT_HEAD
+'
+
+test_expect_success 'failed commit does not clear REVERT_HEAD' '
+       pristine_detach initial &&
+       test_must_fail git revert picked &&
+       test_must_fail git commit &&
+       test_cmp_rev picked REVERT_HEAD
+'
+
 test_expect_success 'revert conflict, diff3 -m style' '
        pristine_detach initial &&
        git config merge.conflictstyle diff3 &&