am: support --allow-empty to record specific empty patches

This option helps to record specific empty patches in the middle
of an am session, which does create empty commits only when:

    1. the index has not changed
    2. lacking a branch

When the index has changed, "--allow-empty" will create a non-empty
commit like passing "--continue" or "--resolved".

Signed-off-by: 徐沛文 (Aleen) <aleen42@vip.qq.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
index 7676bd58ae7beda33544075ee1bae40426c66a75..09107fb106703d14c9e695685e93f59e15362fc3 100644 (file)
--- a/Documentation/git-am.txt
+++ b/Documentation/git-am.txt
@@ -18,7 +18,7 @@ SYNOPSIS
         [--quoted-cr=<action>]
         [--empty=(stop|drop|keep)]
         [(<mbox> | <Maildir>)...]
-'git am' (--continue | --skip | --abort | --quit | --show-current-patch[=(diff|raw)])
+'git am' (--continue | --skip | --abort | --quit | --show-current-patch[=(diff|raw)] | --allow-empty)
 
 DESCRIPTION
 -----------
@@ -200,6 +200,11 @@ default.   You can use `--no-utf8` to override this.
        the e-mail message; if `diff`, show the diff portion only.
        Defaults to `raw`.
 
+--allow-empty::
+       After a patch failure on an input e-mail message lacking a patch,
+       create an empty commit with the contents of the e-mail message
+       as its log message.
+
 DISCUSSION
 ----------
 

diff --git a/builtin/am.c b/builtin/am.c
index 7a66ad237370ef89d24b4bc620b85dd7a3f24445..f2e7e533881083afbf0b52a5ed9f89d6a8bbda2c 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1152,6 +1152,12 @@ static void NORETURN die_user_resolve(const struct am_state *state)
 
                printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
                printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
+
+               if (advice_enabled(ADVICE_AM_WORK_DIR) &&
+                   is_empty_or_missing_file(am_path(state, "patch")) &&
+                   !repo_index_has_changes(the_repository, NULL, NULL))
+                       printf_ln(_("To record the empty patch as an empty commit, run \"%s --allow-empty\"."), cmdline);
+
                printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
        }
 
@@ -1900,19 +1906,24 @@ next:
 /**
  * Resume the current am session after patch application failure. The user did
  * all the hard work, and we do not have to do any patch application. Just
- * trust and commit what the user has in the index and working tree.
+ * trust and commit what the user has in the index and working tree. If `allow_empty`
+ * is true, commit as an empty commit when index has not changed and lacking a patch.
  */
-static void am_resolve(struct am_state *state)
+static void am_resolve(struct am_state *state, int allow_empty)
 {
        validate_resume_state(state);
 
        say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
 
        if (!repo_index_has_changes(the_repository, NULL, NULL)) {
-               printf_ln(_("No changes - did you forget to use 'git add'?\n"
-                       "If there is nothing left to stage, chances are that something else\n"
-                       "already introduced the same changes; you might want to skip this patch."));
-               die_user_resolve(state);
+               if (allow_empty && is_empty_or_missing_file(am_path(state, "patch"))) {
+                       printf_ln(_("No changes - recorded it as an empty commit."));
+               } else {
+                       printf_ln(_("No changes - did you forget to use 'git add'?\n"
+                                   "If there is nothing left to stage, chances are that something else\n"
+                                   "already introduced the same changes; you might want to skip this patch."));
+                       die_user_resolve(state);
+               }
        }
 
        if (unmerged_cache()) {
@@ -2239,7 +2250,8 @@ enum resume_type {
        RESUME_SKIP,
        RESUME_ABORT,
        RESUME_QUIT,
-       RESUME_SHOW_PATCH
+       RESUME_SHOW_PATCH,
+       RESUME_ALLOW_EMPTY,
 };
 
 struct resume_mode {
@@ -2392,6 +2404,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                  N_("show the patch being applied"),
                  PARSE_OPT_CMDMODE | PARSE_OPT_OPTARG | PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
                  parse_opt_show_current_patch, RESUME_SHOW_PATCH },
+               OPT_CMDMODE(0, "allow-empty", &resume.mode,
+                       N_("record the empty patch as an empty commit"),
+                       RESUME_ALLOW_EMPTY),
                OPT_BOOL(0, "committer-date-is-author-date",
                        &state.committer_date_is_author_date,
                        N_("lie about committer date")),
@@ -2500,7 +2515,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                am_run(&state, 1);
                break;
        case RESUME_RESOLVED:
-               am_resolve(&state);
+       case RESUME_ALLOW_EMPTY:
+               am_resolve(&state, resume.mode == RESUME_ALLOW_EMPTY ? 1 : 0);
                break;
        case RESUME_SKIP:
                am_skip(&state);

diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index f2a7a68eda062f180add55744309c241243eb4f3..2db2c5dfe58ccc0bd17da95a729a8ddd70b1d9c2 100755 (executable)
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -1202,4 +1202,61 @@ test_expect_success 'record as an empty commit when meeting e-mail message that
        grep "Creating an empty commit: empty commit" output
 '
 
+test_expect_success 'skip an empty patch in the middle of an am session' '
+       git checkout empty-commit^ &&
+       test_must_fail git am empty-commit.patch >err &&
+       grep "Patch is empty." err &&
+       grep "To record the empty patch as an empty commit, run \"git am --allow-empty\"." err &&
+       git am --skip &&
+       test_path_is_missing .git/rebase-apply &&
+       git rev-parse empty-commit^ >expected &&
+       git rev-parse HEAD >actual &&
+       test_cmp expected actual
+'
+
+test_expect_success 'record an empty patch as an empty commit in the middle of an am session' '
+       git checkout empty-commit^ &&
+       test_must_fail git am empty-commit.patch >err &&
+       grep "Patch is empty." err &&
+       grep "To record the empty patch as an empty commit, run \"git am --allow-empty\"." err &&
+       git am --allow-empty >output &&
+       grep "No changes - recorded it as an empty commit." output &&
+       test_path_is_missing .git/rebase-apply &&
+       git show empty-commit --format="%B" >expected &&
+       git show HEAD --format="%B" >actual &&
+       grep -f actual expected
+'
+
+test_expect_success 'create an non-empty commit when the index IS changed though "--allow-empty" is given' '
+       git checkout empty-commit^ &&
+       test_must_fail git am empty-commit.patch >err &&
+       : >empty-file &&
+       git add empty-file &&
+       git am --allow-empty &&
+       git show empty-commit --format="%B" >expected &&
+       git show HEAD --format="%B" >actual &&
+       grep -f actual expected &&
+       git diff HEAD^..HEAD --name-only
+'
+
+test_expect_success 'cannot create empty commits when there is a clean index due to merge conflicts' '
+       test_when_finished "git am --abort || :" &&
+       git rev-parse HEAD >expected &&
+       test_must_fail git am seq.patch &&
+       test_must_fail git am --allow-empty >err &&
+       ! grep "To record the empty patch as an empty commit, run \"git am --allow-empty\"." err &&
+       git rev-parse HEAD >actual &&
+       test_cmp actual expected
+'
+
+test_expect_success 'cannot create empty commits when there is unmerged index due to merge conflicts' '
+       test_when_finished "git am --abort || :" &&
+       git rev-parse HEAD >expected &&
+       test_must_fail git am -3 seq.patch &&
+       test_must_fail git am --allow-empty >err &&
+       ! grep "To record the empty patch as an empty commit, run \"git am --allow-empty\"." err &&
+       git rev-parse HEAD >actual &&
+       test_cmp actual expected
+'
+
 test_done

diff --git a/t/t7512-status-help.sh b/t/t7512-status-help.sh
index 7f2956d77ad033a57981a9569db3ef803ef93961..2f16d5787edfb16956312a3be70fb9da1ffadc46 100755 (executable)
--- a/t/t7512-status-help.sh
+++ b/t/t7512-status-help.sh
@@ -659,6 +659,7 @@ On branch am_empty
 You are in the middle of an am session.
 The current patch is empty.
   (use "git am --skip" to skip this patch)
+  (use "git am --allow-empty" to record this patch as an empty commit)
   (use "git am --abort" to restore the original branch)
 
 nothing to commit (use -u to show untracked files)

diff --git a/wt-status.c b/wt-status.c
index e4f29b2b4c9f7493076ee904f4c5e2b476841d6c..09045c62e131da7a85ef70371408c224a3d39b84 100644 (file)
--- a/wt-status.c
+++ b/wt-status.c
@@ -1212,17 +1212,23 @@ static void show_merge_in_progress(struct wt_status *s,
 static void show_am_in_progress(struct wt_status *s,
                                const char *color)
 {
+       int am_empty_patch;
+
        status_printf_ln(s, color,
                _("You are in the middle of an am session."));
        if (s->state.am_empty_patch)
                status_printf_ln(s, color,
                        _("The current patch is empty."));
        if (s->hints) {
-               if (!s->state.am_empty_patch)
+               am_empty_patch = s->state.am_empty_patch;
+               if (!am_empty_patch)
                        status_printf_ln(s, color,
                                _("  (fix conflicts and then run \"git am --continue\")"));
                status_printf_ln(s, color,
                        _("  (use \"git am --skip\" to skip this patch)"));
+               if (am_empty_patch)
+                       status_printf_ln(s, color,
+                               _("  (use \"git am --allow-empty\" to record this patch as an empty commit)"));
                status_printf_ln(s, color,
                        _("  (use \"git am --abort\" to restore the original branch)"));
        }