The git-cherry-pick --allow-empty command by default only preserves empty
commits that were originally empty, i.e only those commits for which
<commit>^{tree} and <commit>^^{tree} are equal. By default commits which are
non-empty, but were made empty by the inclusion of a prior commit on the current
history are filtered out. This option allows us to override that behavior and
include redundant commits as empty commits in the change history.
Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
---
Documentation/git-cherry-pick.txt | 12 ++++-
builtin/commit.c | 5 ++
builtin/revert.c | 8 +++-
sequencer.c | 106 ++++++++++++++++++++++++++++++++-----
sequencer.h | 1 +
5 files changed, 117 insertions(+), 15 deletions(-)
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index 730237a..f96b8c5 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -110,7 +110,17 @@ effect to your index in a row.
behavior, allowing empty commits to be preserved automatically
in a cherry-pick. Note that when "--ff" is in effect, empty
commits that meet the "fast-forward" requirement will be kept
- even without this option.
+ even without this option. Note also, that use of this option only
+ keeps commits that were initially empty (i.e. where for commit C
+ C^{tree} and C^^{tree} are equal). Commits which are made empty due to
+ a previous commit are ignored. To force the inclusion of those commits
+ use `--keep-redundant-commits`
+
+--keep-redundant-commits::
+ If a commit being cherry picked duplicates a commit already in the
+ current history, it will result in an empty changeset. By default these
+ redundant commits are ignored. This option overrides that behavior and
+ creates an empty commit object. Implies `--allow-empty`
--strategy=<strategy>::
Use the given merge strategy. Should only be used once.
diff --git a/builtin/commit.c b/builtin/commit.c
index 0cd10ab..c386189 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -61,6 +61,11 @@ N_("The previous cherry-pick is empty.\n"
"\n"
" git cherry-pick --allow-empty\n"
"\n"
+"If the commit was made empty via conflict resolution, and you wish\n"
+"to keep the now-empty commit anyway, use:\n"
+"\n"
+" git cherry-pick --keep-redundant-commits\n"
+"\n"
"Otherwise, please use 'git reset'\n");
static const char *use_message_buffer;
diff --git a/builtin/revert.c b/builtin/revert.c
index 06b00e6..4f0d979 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -115,13 +115,15 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
OPT_END(),
OPT_END(),
OPT_END(),
+ OPT_END(),
};
if (opts->action == REPLAY_PICK) {
struct option cp_extra[] = {
OPT_BOOLEAN('x', NULL, &opts->record_origin, "append commit name"),
OPT_BOOLEAN(0, "ff", &opts->allow_ff, "allow fast-forward"),
- OPT_BOOLEAN(0, "allow-empty", &opts->allow_empty, "preserve empty commits"),
+ OPT_BOOLEAN(0, "allow-empty", &opts->allow_empty, "preserve initially empty commits"),
+ OPT_BOOLEAN(0, "keep-redundant-commits", &opts->keep_if_made_empty, "keep redundant, empty commits"),
OPT_END(),
};
if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
@@ -139,6 +141,10 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
"--abort", rollback,
NULL);
+ /* keep_if_made_empty implies allow_empty */
+ if (opts->keep_if_made_empty)
+ opts->allow_empty = 1;
+
/* Set the subcommand */
if (remove_state)
opts->subcommand = REPLAY_REMOVE_STATE;
diff --git a/sequencer.c b/sequencer.c
index 71929ba..5d033db 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -13,6 +13,7 @@
#include "rerere.h"
#include "merge-recursive.h"
#include "refs.h"
+#include "argv-array.h"
#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
@@ -258,26 +259,102 @@ static int do_recursive_merge(struct commit *base, struct commit *next,
* If we are revert, or if our cherry-pick results in a hand merge,
* we had better say that the current user is responsible for that.
*/
-static int run_git_commit(const char *defmsg, struct replay_opts *opts)
+static int run_git_commit(const char *defmsg, struct replay_opts *opts, int empty)
{
- /* 7 is max possible length of our args array including NULL */
- const char *args[7];
- int i = 0;
+ struct argv_array array;
+ int rc;
+
+ if (!empty && !opts->keep_if_made_empty) {
+ const char *argv[] = { "diff-index", "--quiet", "--exit-code",
+ "--cached", "HEAD", NULL };
+
+ /*
+ * If we run git diff-index with the above option and it returns
+ * zero, then there have been no changes made to the index by
+ * this patch, i.e. its empty. Since our previous empty test
+ * indicated that this patch was not created empty, its been made
+ * redundant. Since keep_if_made_empty is not set, we just skip
+ * it
+ */
+ if (run_command_v_opt(argv, RUN_GIT_CMD) == 0)
+ return 0;
+ }
+
+ argv_array_init(&array);
+ argv_array_push(&array, "commit");
+ argv_array_push(&array, "-n");
- args[i++] = "commit";
- args[i++] = "-n";
if (opts->signoff)
- args[i++] = "-s";
+ argv_array_push(&array, "-s");
if (!opts->edit) {
- args[i++] = "-F";
- args[i++] = defmsg;
+ argv_array_push(&array, "-F");
+ argv_array_push(&array, defmsg);
}
+
if (opts->allow_empty)
- args[i++] = "--allow-empty";
+ argv_array_push(&array, "--allow-empty");
- args[i] = NULL;
- return run_command_v_opt(args, RUN_GIT_CMD);
+ rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
+ argv_array_clear(&array);
+ return rc;
+}
+
+static int is_original_commit_empty(struct commit *commit)
+{
+ struct argv_array argv_array;
+ struct child_process cp;
+ char ptree[40], pptree[40];
+ int ret = 0;
+
+ argv_array_init(&argv_array);
+ memset(&cp, 0, sizeof(struct child_process));
+
+ argv_array_push(&argv_array, "rev-parse");
+ argv_array_pushf(&argv_array, "%s^{tree}", sha1_to_hex(commit->object.sha1));
+
+ cp.git_cmd = 1;
+ cp.no_stdin = 1;
+ cp.no_stderr = 1;
+ cp.out = -1;
+ cp.argv = argv_array.argv;
+
+ if (start_command(&cp) < 0)
+ goto out;
+
+ if (read_in_full(cp.out, ptree, sizeof(ptree)) < sizeof(ptree)) {
+ close(cp.out);
+ goto out;
+ }
+
+ close(cp.out);
+
+ finish_command(&cp);
+
+ argv_array_clear(&argv_array);
+
+ argv_array_push(&argv_array, "rev-parse");
+ argv_array_pushf(&argv_array, "%s^^{tree}", sha1_to_hex(commit->object.sha1));
+ cp.out = -1;
+ cp.argv = argv_array.argv;
+
+ if (start_command(&cp) < 0)
+ goto out;
+
+ if (read_in_full(cp.out, pptree, sizeof(pptree)) < sizeof(ptree)) {
+ close(cp.out);
+ goto out;
+ }
+
+ close(cp.out);
+
+ finish_command(&cp);
+
+ if (!strncmp(ptree, pptree, sizeof(ptree)))
+ ret = 1;
+out:
+ argv_array_clear(&argv_array);
+ return ret;
}
static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
@@ -289,6 +366,7 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
char *defmsg = NULL;
struct strbuf msgbuf = STRBUF_INIT;
int res;
+ int empty_commit;
if (opts->no_commit) {
/*
@@ -414,6 +492,8 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
free_commit_list(remotes);
}
+ empty_commit = is_original_commit_empty(commit);
+
/*
* If the merge was clean or if it failed due to conflict, we write
* CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
@@ -435,7 +515,7 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
rerere(opts->allow_rerere_auto);
} else {
if (!opts->no_commit)
- res = run_git_commit(defmsg, opts);
+ res = run_git_commit(defmsg, opts, empty_commit);
}
free_message(&msg);
diff --git a/sequencer.h b/sequencer.h
index e2cd725..862a79a 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -30,6 +30,7 @@ struct replay_opts {
int allow_ff;
int allow_rerere_auto;
int allow_empty;
+ int keep_if_made_empty;
int mainline;
--
1.7.7.6
--
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