When a series of patches for a topic-B depends on having topic-A,
the workflow to prepare the topic-B branch would look like this:
$ git checkout -b topic-B main
$ git merge --no-ff --no-edit topic-A
$ git am <mbox-for-topic-B
When topic-A gets updated, recreating the first merge and rebasing
the rest of the topic-B, all on detached HEAD, is a useful
technique. After updating topic-A with its new round of patches:
$ git checkout topic-B
$ prev=$(git rev-parse 'HEAD^{/^Merge branch .topic-A. into}')
$ git checkout --detach $prev^1
$ git merge --no-ff --no-edit topic-A
$ git rebase --onto HEAD $prev @{-1}^0
$ git checkout -B @{-1}
This will
(0) check out the current topic-B.
(1) find the previous merge of topic-A into topic-B.
(2) detach the HEAD to the parent of the previous merge.
(3) merge the updated topic-A to it.
(4) reapply the patches to rebuild the rest of topic-B.
(5) update topic-B with the result.
without contaminating the reflog of topic-B too much. topic-B@{1}
is the "logically previous" state before topic-A got updated, for
example. At (4), comparison (e.g. range-diff) between HEAD and
@{-1} is a meaningful way to sanity check the result, and the same
can be done at (5) by comparing topic-B and topic-B@{1}.
But there is one glitch. The merge into the detached HEAD done in
the step (3) above gives us "Merge branch 'topic-A' into HEAD", and
does not say "into topic-B".
Teach the "--into-name=<branch>" option to "git merge" and its
underlying "git fmt-merge-message", to pretend as if we were merging
into <branch>, no matter what branch we are actually merging into,
when they prepare the merge message. The pretend name honors the
usual "into <target>" suppression mechanism, which can be seen in
the tests added here.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
Range-diff:
1: 0ada838311 ! 1: 273df9ed2a merge: allow to pretend a merge into detached HEAD is made into a branch
@@ Metadata
Author: Junio C Hamano <gitster@xxxxxxxxx>
## Commit message ##
- merge: allow to pretend a merge into detached HEAD is made into a branch
+ merge: allow to pretend a merge is made into a different branch
When a series of patches for a topic-B depends on having topic-A,
the workflow to prepare the topic-B branch would look like this:
@@ Commit message
the step (3) above gives us "Merge branch 'topic-A' into HEAD", and
does not say "into topic-B".
- Teach the "--detached-head-name=<branch>" option to "git merge" and
- its underlying "git fmt-merge-message", to pretend as if we were
- merging into <branch> (instead of HEAD) when they prepare the merge
- message. The pretend name honors the usual "into <target>"
- suppression mechanism, which can be seen in the tests added here.
+ Teach the "--into-name=<branch>" option to "git merge" and its
+ underlying "git fmt-merge-message", to pretend as if we were merging
+ into <branch>, no matter what branch we are actually merging into,
+ when they prepare the merge message. The pretend name honors the
+ usual "into <target>" suppression mechanism, which can be seen in
+ the tests added here.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
@@ Documentation/git-fmt-merge-msg.txt: git-fmt-merge-msg - Produce a merge commit
--------
[verse]
-'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log]
-+'git fmt-merge-msg' [-m <message>] [--detached-head-name <branch>] [--log[=<n>] | --no-log]
++'git fmt-merge-msg' [-m <message>] [--into-name <branch>] [--log[=<n>] | --no-log]
'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log] -F <file>
DESCRIPTION
@@ Documentation/git-fmt-merge-msg.txt: OPTIONS
Use <message> instead of the branch names for the first line
of the log message. For use with `--log`.
-+--detached-head-name <branch>::
-+ When merging into a detached HEAD, prepare the merge
-+ message as if merging to the branch `<branch>` instead.
++--into-name <branch>::
++ Prepare the merge message as if merging to the branch `<branch>`,
++ instead of the name of the real branch to which the merge is made.
+
-F <file>::
--file <file>::
@@ Documentation/git-merge.txt: SYNOPSIS
[--[no-]allow-unrelated-histories]
- [--[no-]rerere-autoupdate] [-m <msg>] [-F <file>] [<commit>...]
+ [--[no-]rerere-autoupdate] [-m <msg>] [-F <file>]
-+ [--detached-head-name <branch>] [<commit>...]
++ [--into-name <branch>] [<commit>...]
'git merge' (--continue | --abort | --quit)
DESCRIPTION
@@ Documentation/git-merge.txt: The 'git fmt-merge-msg' command can be
used to give a good default for automated 'git merge'
invocations. The automated message can include the branch description.
-+--detached-head-name <branch>::
-+ When merging into a detached HEAD, prepare the default merge
-+ message as if merging to the branch `<branch>` instead.
++--into-name <branch>::
++ Prepare the default merge message as if merging to the branch
++ `<branch>`, instead of the name of the real branch to which
++ the merge is made.
+
-F <file>::
--file=<file>::
@@ builtin/fmt-merge-msg.c: int cmd_fmt_merge_msg(int argc, const char **argv, cons
{
const char *inpath = NULL;
const char *message = NULL;
-+ char *detached_head_name = NULL;
++ char *into_name = NULL;
int shortlog_len = -1;
struct option options[] = {
{ OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
@@ builtin/fmt-merge-msg.c: int cmd_fmt_merge_msg(int argc, const char **argv, cons
DEFAULT_MERGE_LOG_LEN },
OPT_STRING('m', "message", &message, N_("text"),
N_("use <text> as start of message")),
-+ OPT_STRING(0, "detached", &detached_head_name, N_("name"),
-+ N_("use <name> instead of detached HEAD")),
++ OPT_STRING(0, "into-name", &into_name, N_("name"),
++ N_("use <name> instead of the real target branch")),
OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
OPT_END()
};
@@ builtin/fmt-merge-msg.c: int cmd_fmt_merge_msg(int argc, const char **argv, cons
opts.add_title = !message;
opts.credit_people = 1;
opts.shortlog_len = shortlog_len;
-+ opts.detached_head_name = detached_head_name;
++ opts.into_name = into_name;
ret = fmt_merge_msg(&input, &output, &opts);
if (ret)
@@ builtin/merge.c: static int signoff;
static const char *sign_commit;
static int autostash;
static int no_verify;
-+static char *detached_head_name;
++static char *into_name;
static struct strategy all_strategy[] = {
{ "recursive", NO_TRIVIAL },
@@ builtin/merge.c: static struct option builtin_merge_options[] = {
{ OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
N_("read message from file"), PARSE_OPT_NONEG,
NULL, 0, option_read_message },
-+ OPT_STRING(0, "detached", &detached_head_name, N_("name"),
-+ N_("use <name> instead of detached HEAD")),
++ OPT_STRING(0, "into-name", &into_name, N_("name"),
++ N_("use <name> instead of the real target")),
OPT__VERBOSITY(&verbosity),
OPT_BOOL(0, "abort", &abort_current_merge,
N_("abort the current in-progress merge")),
@@ builtin/merge.c: static void prepare_merge_message(struct strbuf *merge_names, s
opts.add_title = !have_message;
opts.shortlog_len = shortlog_len;
opts.credit_people = (0 < option_edit);
-+ opts.detached_head_name = detached_head_name;
++ opts.into_name = into_name;
fmt_merge_msg(merge_names, merge_msg, &opts);
if (merge_msg->len)
## fmt-merge-msg.c ##
@@ fmt-merge-msg.c: int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+
+ memset(&merge_parents, 0, sizeof(merge_parents));
+
+- /* get current branch */
++ /* learn the commit that we merge into and the current branch name */
+ current_branch = current_branch_to_free =
+ resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
+ if (!current_branch)
die("No current branch");
- if (starts_with(current_branch, "refs/heads/"))
+- if (starts_with(current_branch, "refs/heads/"))
++
++ if (opts->into_name)
++ current_branch = opts->into_name;
++ else if (starts_with(current_branch, "refs/heads/"))
current_branch += 11;
-+ else if (!strcmp(current_branch, "HEAD") && opts->detached_head_name)
-+ current_branch = opts->detached_head_name;
find_merge_parents(&merge_parents, in, &head_oid);
-
## fmt-merge-msg.h ##
@@ fmt-merge-msg.h: struct fmt_merge_msg_opts {
unsigned add_title:1,
credit_people:1;
int shortlog_len;
-+ const char *detached_head_name;
++ const char *into_name;
};
extern int merge_log_config;
@@ t/t6200-fmt-merge-msg.sh: test_expect_success 'merge-msg with "merging" an annot
test_cmp expected .git/MERGE_MSG
'
-+test_expect_success 'merge --detached=<name>' '
++test_expect_success 'merge --into-name=<name>' '
+ test_when_finished "git checkout main" &&
+ git checkout -B side main &&
+ git commit --allow-empty -m "One step ahead" &&
@@ t/t6200-fmt-merge-msg.sh: test_expect_success 'merge-msg with "merging" an annot
+ grep -e "Merge branch .side. into HEAD$" actual &&
+
+ git reset --hard main &&
-+ git merge --no-ff --detached=main side &&
++ git merge --no-ff --into-name=main side &&
+ git show -s --format="%s" >full.1 &&
+ head -n1 full.1 >actual &&
+ # expect that we pretend to be merging to main, that is suppressed
++ grep -e "Merge branch .side.$" actual &&
++
++ git checkout -b throwaway main &&
++ git merge --no-ff --into-name=main side &&
++ git show -s --format="%s" >full.2 &&
++ head -n1 full.2 >actual &&
++ # expect that we pretend to be merging to main, that is suppressed
+ grep -e "Merge branch .side.$" actual
+'
+
@@ t/t6200-fmt-merge-msg.sh: test_expect_success 'merge.suppressDest configuration'
+ grep -e "Merge branch .side. into HEAD$" actual &&
+
+ git -c merge.suppressDest="main" fmt-merge-msg \
-+ --detached=main <.git/FETCH_HEAD >full.5 &&
++ --into-name=main <.git/FETCH_HEAD >full.5 &&
+ head -n1 full.5 >actual &&
+ grep -e "Merge branch .side." actual &&
+ ! grep -e " into main$" actual &&
Documentation/git-fmt-merge-msg.txt | 6 ++++-
Documentation/git-merge.txt | 8 +++++-
builtin/fmt-merge-msg.c | 4 +++
builtin/merge.c | 4 +++
fmt-merge-msg.c | 7 +++--
fmt-merge-msg.h | 1 +
t/t6200-fmt-merge-msg.sh | 42 ++++++++++++++++++++++++++++-
7 files changed, 67 insertions(+), 5 deletions(-)
diff --git a/Documentation/git-fmt-merge-msg.txt b/Documentation/git-fmt-merge-msg.txt
index 6793d8fc05..6f28812f38 100644
--- a/Documentation/git-fmt-merge-msg.txt
+++ b/Documentation/git-fmt-merge-msg.txt
@@ -9,7 +9,7 @@ git-fmt-merge-msg - Produce a merge commit message
SYNOPSIS
--------
[verse]
-'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log]
+'git fmt-merge-msg' [-m <message>] [--into-name <branch>] [--log[=<n>] | --no-log]
'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log] -F <file>
DESCRIPTION
@@ -44,6 +44,10 @@ OPTIONS
Use <message> instead of the branch names for the first line
of the log message. For use with `--log`.
+--into-name <branch>::
+ Prepare the merge message as if merging to the branch `<branch>`,
+ instead of the name of the real branch to which the merge is made.
+
-F <file>::
--file <file>::
Take the list of merged objects from <file> instead of
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index e4f3352eb5..ed0990621f 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -12,7 +12,8 @@ SYNOPSIS
'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
[--no-verify] [-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
[--[no-]allow-unrelated-histories]
- [--[no-]rerere-autoupdate] [-m <msg>] [-F <file>] [<commit>...]
+ [--[no-]rerere-autoupdate] [-m <msg>] [-F <file>]
+ [--into-name <branch>] [<commit>...]
'git merge' (--continue | --abort | --quit)
DESCRIPTION
@@ -76,6 +77,11 @@ The 'git fmt-merge-msg' command can be
used to give a good default for automated 'git merge'
invocations. The automated message can include the branch description.
+--into-name <branch>::
+ Prepare the default merge message as if merging to the branch
+ `<branch>`, instead of the name of the real branch to which
+ the merge is made.
+
-F <file>::
--file=<file>::
Read the commit message to be used for the merge commit (in
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 48a8699de7..8d8fd393f8 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -12,6 +12,7 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
{
const char *inpath = NULL;
const char *message = NULL;
+ char *into_name = NULL;
int shortlog_len = -1;
struct option options[] = {
{ OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
@@ -23,6 +24,8 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
DEFAULT_MERGE_LOG_LEN },
OPT_STRING('m', "message", &message, N_("text"),
N_("use <text> as start of message")),
+ OPT_STRING(0, "into-name", &into_name, N_("name"),
+ N_("use <name> instead of the real target branch")),
OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
OPT_END()
};
@@ -56,6 +59,7 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
opts.add_title = !message;
opts.credit_people = 1;
opts.shortlog_len = shortlog_len;
+ opts.into_name = into_name;
ret = fmt_merge_msg(&input, &output, &opts);
if (ret)
diff --git a/builtin/merge.c b/builtin/merge.c
index ea3112e0c0..1ba5951d49 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -87,6 +87,7 @@ static int signoff;
static const char *sign_commit;
static int autostash;
static int no_verify;
+static char *into_name;
static struct strategy all_strategy[] = {
{ "recursive", NO_TRIVIAL },
@@ -286,6 +287,8 @@ static struct option builtin_merge_options[] = {
{ OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
N_("read message from file"), PARSE_OPT_NONEG,
NULL, 0, option_read_message },
+ OPT_STRING(0, "into-name", &into_name, N_("name"),
+ N_("use <name> instead of the real target")),
OPT__VERBOSITY(&verbosity),
OPT_BOOL(0, "abort", &abort_current_merge,
N_("abort the current in-progress merge")),
@@ -1122,6 +1125,7 @@ static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *mer
opts.add_title = !have_message;
opts.shortlog_len = shortlog_len;
opts.credit_people = (0 < option_edit);
+ opts.into_name = into_name;
fmt_merge_msg(merge_names, merge_msg, &opts);
if (merge_msg->len)
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 5216191488..d25594545c 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -649,12 +649,15 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
memset(&merge_parents, 0, sizeof(merge_parents));
- /* get current branch */
+ /* learn the commit that we merge into and the current branch name */
current_branch = current_branch_to_free =
resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
if (!current_branch)
die("No current branch");
- if (starts_with(current_branch, "refs/heads/"))
+
+ if (opts->into_name)
+ current_branch = opts->into_name;
+ else if (starts_with(current_branch, "refs/heads/"))
current_branch += 11;
find_merge_parents(&merge_parents, in, &head_oid);
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index f2ab0e0085..99054042dc 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -9,6 +9,7 @@ struct fmt_merge_msg_opts {
unsigned add_title:1,
credit_people:1;
int shortlog_len;
+ const char *into_name;
};
extern int merge_log_config;
diff --git a/t/t6200-fmt-merge-msg.sh b/t/t6200-fmt-merge-msg.sh
index 06c5fb5615..d861d7ca28 100755
--- a/t/t6200-fmt-merge-msg.sh
+++ b/t/t6200-fmt-merge-msg.sh
@@ -573,7 +573,35 @@ test_expect_success 'merge-msg with "merging" an annotated tag' '
test_cmp expected .git/MERGE_MSG
'
+test_expect_success 'merge --into-name=<name>' '
+ test_when_finished "git checkout main" &&
+ git checkout -B side main &&
+ git commit --allow-empty -m "One step ahead" &&
+
+ git checkout --detach main &&
+ git merge --no-ff side &&
+ git show -s --format="%s" >full.0 &&
+ head -n1 full.0 >actual &&
+ # expect that HEAD is shown as-is
+ grep -e "Merge branch .side. into HEAD$" actual &&
+
+ git reset --hard main &&
+ git merge --no-ff --into-name=main side &&
+ git show -s --format="%s" >full.1 &&
+ head -n1 full.1 >actual &&
+ # expect that we pretend to be merging to main, that is suppressed
+ grep -e "Merge branch .side.$" actual &&
+
+ git checkout -b throwaway main &&
+ git merge --no-ff --into-name=main side &&
+ git show -s --format="%s" >full.2 &&
+ head -n1 full.2 >actual &&
+ # expect that we pretend to be merging to main, that is suppressed
+ grep -e "Merge branch .side.$" actual
+'
+
test_expect_success 'merge.suppressDest configuration' '
+ test_when_finished "git checkout main" &&
git checkout -B side main &&
git commit --allow-empty -m "One step ahead" &&
git checkout main &&
@@ -590,7 +618,19 @@ test_expect_success 'merge.suppressDest configuration' '
git -c merge.suppressDest="ma?*[rn]" fmt-merge-msg <.git/FETCH_HEAD >full.3 &&
head -n1 full.3 >actual &&
grep -e "Merge branch .side." actual &&
- ! grep -e " into main$" actual
+ ! grep -e " into main$" actual &&
+
+ git checkout --detach HEAD &&
+ git -c merge.suppressDest="main" fmt-merge-msg <.git/FETCH_HEAD >full.4 &&
+ head -n1 full.4 >actual &&
+ grep -e "Merge branch .side. into HEAD$" actual &&
+
+ git -c merge.suppressDest="main" fmt-merge-msg \
+ --into-name=main <.git/FETCH_HEAD >full.5 &&
+ head -n1 full.5 >actual &&
+ grep -e "Merge branch .side." actual &&
+ ! grep -e " into main$" actual &&
+ ! grep -e " into HEAD$" actual
'
test_done
--
2.34.1-472-g213ab46be7
