Merge branch 'mv/merge-ff-tristate'

The configuration variable "merge.ff" was cleary a tri-state to
choose one from "favor fast-forward when possible", "always create
a merge even when the history could fast-forward" and "do not
create any merge, only update when the history fast-forwards", but
the command line parser did not implement the usual convention of
"last one wins, and command line overrides the configuration"
correctly.

* mv/merge-ff-tristate:
merge: handle --ff/--no-ff/--ff-only as a tri-state option

diff --git a/builtin/merge.c b/builtin/merge.c
index bad4536a8738237a87e51011f074814bd8b10ba3..9505e7e426d302522f5e065d741fccd37290ea21 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -47,8 +47,8 @@ static const char * const builtin_merge_usage[] = {
 };
 
 static int show_diffstat = 1, shortlog_len = -1, squash;
-static int option_commit = 1, allow_fast_forward = 1;
-static int fast_forward_only, option_edit = -1;
+static int option_commit = 1;
+static int option_edit = -1;
 static int allow_trivial = 1, have_message, verify_signatures;
 static int overwrite_ignore = 1;
 static struct strbuf merge_msg = STRBUF_INIT;
@@ -76,6 +76,14 @@ static struct strategy all_strategy[] = {
 
 static const char *pull_twohead, *pull_octopus;
 
+enum ff_type {
+       FF_NO,
+       FF_ALLOW,
+       FF_ONLY
+};
+
+static enum ff_type fast_forward = FF_ALLOW;
+
 static int option_parse_message(const struct option *opt,
                                const char *arg, int unset)
 {
@@ -178,6 +186,13 @@ static int option_parse_n(const struct option *opt,
        return 0;
 }
 
+static int option_parse_ff_only(const struct option *opt,
+                         const char *arg, int unset)
+{
+       fast_forward = FF_ONLY;
+       return 0;
+}
+
 static struct option builtin_merge_options[] = {
        { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
                N_("do not show a diffstat at the end of the merge"),
@@ -194,10 +209,10 @@ static struct option builtin_merge_options[] = {
                N_("perform a commit if the merge succeeds (default)")),
        OPT_BOOL('e', "edit", &option_edit,
                N_("edit message before committing")),
-       OPT_BOOLEAN(0, "ff", &allow_fast_forward,
-               N_("allow fast-forward (default)")),
-       OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
-               N_("abort if fast-forward is not possible")),
+       OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
+       { OPTION_CALLBACK, 0, "ff-only", NULL, NULL,
+               N_("abort if fast-forward is not possible"),
+               PARSE_OPT_NOARG | PARSE_OPT_NONEG, option_parse_ff_only },
        OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
        OPT_BOOL(0, "verify-signatures", &verify_signatures,
                N_("Verify that the named commit has a valid GPG signature")),
@@ -581,10 +596,9 @@ static int git_merge_config(const char *k, const char *v, void *cb)
        else if (!strcmp(k, "merge.ff")) {
                int boolval = git_config_maybe_bool(k, v);
                if (0 <= boolval) {
-                       allow_fast_forward = boolval;
+                       fast_forward = boolval ? FF_ALLOW : FF_NO;
                } else if (v && !strcmp(v, "only")) {
-                       allow_fast_forward = 1;
-                       fast_forward_only = 1;
+                       fast_forward = FF_ONLY;
                } /* do not barf on values from future versions of git */
                return 0;
        } else if (!strcmp(k, "merge.defaulttoupstream")) {
@@ -863,7 +877,7 @@ static int finish_automerge(struct commit *head,
 
        free_commit_list(common);
        parents = remoteheads;
-       if (!head_subsumed || !allow_fast_forward)
+       if (!head_subsumed || fast_forward == FF_NO)
                commit_list_insert(head, &parents);
        strbuf_addch(&merge_msg, '\n');
        prepare_to_commit(remoteheads);
@@ -1008,7 +1022,7 @@ static void write_merge_state(struct commit_list *remoteheads)
        if (fd < 0)
                die_errno(_("Could not open '%s' for writing"), filename);
        strbuf_reset(&buf);
-       if (!allow_fast_forward)
+       if (fast_forward == FF_NO)
                strbuf_addf(&buf, "no-ff");
        if (write_in_full(fd, buf.buf, buf.len) != buf.len)
                die_errno(_("Could not write to '%s'"), filename);
@@ -1157,14 +1171,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                show_diffstat = 0;
 
        if (squash) {
-               if (!allow_fast_forward)
+               if (fast_forward == FF_NO)
                        die(_("You cannot combine --squash with --no-ff."));
                option_commit = 0;
        }
 
-       if (!allow_fast_forward && fast_forward_only)
-               die(_("You cannot combine --no-ff with --ff-only."));
-
        if (!abort_current_merge) {
                if (!argc) {
                        if (default_to_upstream)
@@ -1206,7 +1217,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                                "empty head"));
                if (squash)
                        die(_("Squash commit into empty head not supported yet"));
-               if (!allow_fast_forward)
+               if (fast_forward == FF_NO)
                        die(_("Non-fast-forward commit does not make sense into "
                            "an empty head"));
                remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
@@ -1294,11 +1305,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                            sha1_to_hex(commit->object.sha1));
                setenv(buf.buf, merge_remote_util(commit)->name, 1);
                strbuf_reset(&buf);
-               if (!fast_forward_only &&
+               if (fast_forward != FF_ONLY &&
                    merge_remote_util(commit) &&
                    merge_remote_util(commit)->obj &&
                    merge_remote_util(commit)->obj->type == OBJ_TAG)
-                       allow_fast_forward = 0;
+                       fast_forward = FF_NO;
        }
 
        if (option_edit < 0)
@@ -1315,7 +1326,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 
        for (i = 0; i < use_strategies_nr; i++) {
                if (use_strategies[i]->attr & NO_FAST_FORWARD)
-                       allow_fast_forward = 0;
+                       fast_forward = FF_NO;
                if (use_strategies[i]->attr & NO_TRIVIAL)
                        allow_trivial = 0;
        }
@@ -1345,7 +1356,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                 */
                finish_up_to_date("Already up-to-date.");
                goto done;
-       } else if (allow_fast_forward && !remoteheads->next &&
+       } else if (fast_forward != FF_NO && !remoteheads->next &&
                        !common->next &&
                        !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
                /* Again the most common case of merging one remote. */
@@ -1392,7 +1403,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                 * only one common.
                 */
                refresh_cache(REFRESH_QUIET);
-               if (allow_trivial && !fast_forward_only) {
+               if (allow_trivial && fast_forward != FF_ONLY) {
                        /* See if it is really trivial. */
                        git_committer_info(IDENT_STRICT);
                        printf(_("Trying really trivial in-index merge...\n"));
@@ -1433,7 +1444,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                }
        }
 
-       if (fast_forward_only)
+       if (fast_forward == FF_ONLY)
                die(_("Not possible to fast-forward, aborting."));
 
        /* We are going to make a new commit. */

diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 460d8ebf48f9ab3826e58e2e9285f6faecd79b78..3ff5fb853c941586e3e5ed69a74a628dfe5bb84a 100755 (executable)
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -497,9 +497,15 @@ test_expect_success 'combining --squash and --no-ff is refused' '
        test_must_fail git merge --no-ff --squash c1
 '
 
-test_expect_success 'combining --ff-only and --no-ff is refused' '
-       test_must_fail git merge --ff-only --no-ff c1 &&
-       test_must_fail git merge --no-ff --ff-only c1
+test_expect_success 'option --ff-only overwrites --no-ff' '
+       git merge --no-ff --ff-only c1 &&
+       test_must_fail git merge --no-ff --ff-only c2
+'
+
+test_expect_success 'option --ff-only overwrites merge.ff=only config' '
+       git reset --hard c0 &&
+       test_config merge.ff only &&
+       git merge --no-ff c1
 '
 
 test_expect_success 'merge c0 with c1 (ff overrides no-ff)' '