Since we'll be using git-cherry-pick to enhance git-rebase's ability to preserve
empty commits, we open ourselves to the possibility of preserving commits that
are made empty by a previous merge as well, which is almost certainly not what
we want (most of the time). To handle this, we can add the ignore-if-made-empty
option. If enabled, it will look at cherry-picked commits, and if the origional
sha1 has the same tree as its parent, then the cherry-pick is comitted as an
empty commit, otherwise the commit is skipped (because it previously made
changes to the tree, but no longer does).
Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
CC: Jeff King <peff@xxxxxxxx>
CC: Phil Hord <phil.hord@xxxxxxxxx>
CC: Junio C Hamano <gitster@xxxxxxxxx>
---
Documentation/git-cherry-pick.txt | 10 +++-
builtin/revert.c | 2 +
sequencer.c | 113 ++++++++++++++++++++++++++++++++-----
sequencer.h | 1 +
4 files changed, 111 insertions(+), 15 deletions(-)
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index c283d8c..bb7eb4a 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -103,7 +103,7 @@ effect to your index in a row.
cherry-pick'ed commit, then a fast forward to this commit will
be performed.
---allow-empty:
+--allow-empty:::
By default, cherry-picking an empty commit will fail,
indicating that an explicit invocation of `git commit
--allow-empty` is required. This option overrides that
@@ -112,6 +112,14 @@ effect to your index in a row.
commits that meet the "fast-forward" requirement will be kept
even without this option.
+--ignore-if-made-empty::
+ If the --allow-empty option is used, all empty commits are kept,
+ including those which were made empty due to a previous change.
+ While this may be desireable, likely it is not. This option
+ restricts the scope of --allow-empty to only those commits which
+ were created as empty commits (i.e. if for commit C, C^{tree} and
+ C^^{tree} are identical).
+
--strategy=<strategy>::
Use the given merge strategy. Should only be used once.
See the MERGE STRATEGIES section in linkgit:git-merge[1]
diff --git a/builtin/revert.c b/builtin/revert.c
index 06b00e6..0fa76ca 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -115,6 +115,7 @@ 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) {
@@ -122,6 +123,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
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, "ignore-if-made-empty", &opts->ignore_if_made_empty, "ignore commits already in tree"),
OPT_END(),
};
if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
diff --git a/sequencer.c b/sequencer.c
index 71929ba..a512598 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 +259,107 @@ 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)
-{
- /* 7 is max possible length of our args array including NULL */
- const char *args[7];
- int i = 0;
+static int run_git_commit(const char *defmsg, struct replay_opts *opts, int empty)
+{
+ struct argv_array array;
+ int rc;
+
+ argv_array_init(&array);
+ argv_array_push(&array, "commit");
+ argv_array_push(&array, "-n");
+
+ if ((!empty) && (opts->ignore_if_made_empty)) {
+ /* Note: This implies --dry-run */
+ argv_array_push(&array, "--porcelain");
+ if (run_command_v_opt(array.argv, RUN_GIT_CMD) == 1) {
+ /* The dry run exit code of 1 tells us this is
+ * an empty commit, just skip it.
+ */
+ argv_array_clear(&array);
+ return 0;
+ }
+ argv_array_pop(&array, 1);
+ }
+
- 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");
+
+
+ rc = run_command_v_opt(array.argv, RUN_GIT_CMD);
+ argv_array_clear(&array);
+ return rc;
+}
+
+static int is_origional_commit_empty(struct commit *commit)
+{
+ struct argv_array argv_array;
+ struct child_process cp;
+ char ptree[41], pptree[41];
+ int pipefd[2];
+ FILE *output;
+ int ret = 0;
+
+ if (pipe2(pipefd, 0) < 0)
+ return 0;
+
+ output = xfdopen(pipefd[0], "r");
+
+ argv_array_init(&argv_array);
+ memset(&cp, 0, sizeof(struct child_process));
- args[i] = NULL;
+ argv_array_push(&argv_array, "rev-parse");
+ argv_array_pushf(&argv_array, "%s^{tree}", sha1_to_hex(commit->object.sha1));
- return run_command_v_opt(args, RUN_GIT_CMD);
+ cp.git_cmd = 1;
+ cp.no_stdin = 1;
+ cp.no_stderr = 1;
+ cp.out = pipefd[1];
+ cp.argv = argv_array.argv;
+
+ if (start_command(&cp) < 0)
+ goto out;
+
+ if (fscanf(output, "%s\n", ptree) < 1)
+ goto out;
+
+ finish_command(&cp);
+
+ fclose(output);
+ close(pipefd[0]);
+ argv_array_clear(&argv_array);
+
+ if (pipe2(pipefd, 0) < 0)
+ return 0;
+
+ output = xfdopen(pipefd[0], "r");
+
+ argv_array_push(&argv_array, "rev-parse");
+ argv_array_pushf(&argv_array, "%s^^{tree}", sha1_to_hex(commit->object.sha1));
+ cp.argv = argv_array.argv;
+
+ if (start_command(&cp) < 0)
+ goto out;
+
+ if (fscanf(output, "%s\n", pptree) < 1)
+ goto out;
+
+ finish_command(&cp);
+ close(pipefd[0]);
+
+ if (!strncmp(ptree, pptree, 40))
+ ret = 1;
+out:
+ fclose(output);
+ argv_array_clear(&argv_array);
+ return ret;
}
static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
@@ -289,6 +371,7 @@ 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 +497,8 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
free_commit_list(remotes);
}
+ empty_commit = is_origional_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 +520,7 @@ 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..3e1106f 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 ignore_if_made_empty;
int mainline;
--
1.7.7.6
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html