reset: give better reflog messages

The reset command creates its reflog entry from argv.
However, it does so after having run parse_options, which
means the only thing left in argv is any non-option
arguments. Thus you would end up with confusing reflog
entries like:

  $ git reset --hard HEAD^
  $ git reset --soft HEAD@{1}
  $ git log -2 -g --oneline
  8e46cad HEAD@{0}: HEAD@{1}: updating HEAD
  1eb9486 HEAD@{1}: HEAD^: updating HEAD

However, we must also consider that some scripts may set
GIT_REFLOG_ACTION before calling reset, and we need to show
their reflog action (with our text appended). For example:

  rebase -i (squash): updating HEAD

On top of that, we also set the ORIG_HEAD reflog action
(even though it doesn't generally exist). In that case, the
reset argument is somewhat meaningless, as it has nothing to
do with what's in ORIG_HEAD.

This patch changes the reset reflog code to show:

  $GIT_REFLOG_ACTION: updating {HEAD,ORIG_HEAD}

as before, but only if GIT_REFLOG_ACTION is set. Otherwise,
show:

   reset: moving to $rev

for HEAD, and:

   reset: updating ORIG_HEAD

for ORIG_HEAD (this is still somewhat superfluous, since we
are in the ORIG_HEAD reflog, obviously, but at least we now
mention which command was used to update it).

While we're at it, we can clean up the code a bit:

 - Use strbufs to make the message.

 - Use the "rev" parameter instead of showing all options.
   This makes more sense, since it is the only thing
   impacting the writing of the ref.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/reset.c b/builtin/reset.c
index 98bca04..27b3426 100644 (file)
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -33,25 +33,6 @@ static const char *reset_type_names[] = {
        N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
 };
 
-static char *args_to_str(const char **argv)
-{
-       char *buf = NULL;
-       unsigned long len, space = 0, nr = 0;
-
-       for (; *argv; argv++) {
-               len = strlen(*argv);
-               ALLOC_GROW(buf, nr + 1 + len, space);
-               if (nr)
-                       buf[nr++] = ' ';
-               memcpy(buf + nr, *argv, len);
-               nr += len;
-       }
-       ALLOC_GROW(buf, nr + 1, space);
-       buf[nr] = '\0';
-
-       return buf;
-}
-
 static inline int is_merge(void)
 {
        return !access(git_path("MERGE_HEAD"), F_OK);
@@ -215,14 +196,18 @@ static int read_from_tree(const char *prefix, const char **argv,
        return update_index_refresh(index_fd, lock, refresh_flags);
 }
 
-static void prepend_reflog_action(const char *action, char *buf, size_t size)
+static void set_reflog_message(struct strbuf *sb, const char *action,
+                              const char *rev)
 {
-       const char *sep = ": ";
        const char *rla = getenv("GIT_REFLOG_ACTION");
-       if (!rla)
-               rla = sep = "";
-       if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
-               warning(_("Reflog action message too long: %.*s..."), 50, buf);
+
+       strbuf_reset(sb);
+       if (rla)
+               strbuf_addf(sb, "%s: %s", rla, action);
+       else if (rev)
+               strbuf_addf(sb, "reset: moving to %s", rev);
+       else
+               strbuf_addf(sb, "reset: %s", action);
 }
 
 static void die_if_unmerged_cache(int reset_type)
@@ -241,7 +226,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
                                *old_orig = NULL, sha1_old_orig[20];
        struct commit *commit;
-       char *reflog_action, msg[1024];
+       struct strbuf msg = STRBUF_INIT;
        const struct option options[] = {
                OPT__QUIET(&quiet, "be quiet, only report errors"),
                OPT_SET_INT(0, "mixed", &reset_type,
@@ -261,8 +246,6 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
                                                PARSE_OPT_KEEP_DASHDASH);
-       reflog_action = args_to_str(argv);
-       setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 
        /*
         * Possible arguments are:
@@ -357,13 +340,13 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                old_orig = sha1_old_orig;
        if (!get_sha1("HEAD", sha1_orig)) {
                orig = sha1_orig;
-               prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
-               update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
+               set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
+               update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
        }
        else if (old_orig)
                delete_ref("ORIG_HEAD", old_orig, 0);
-       prepend_reflog_action("updating HEAD", msg, sizeof(msg));
-       update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
+       set_reflog_message(&msg, "updating HEAD", rev);
+       update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 
        switch (reset_type) {
        case HARD:
@@ -380,7 +363,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
        remove_branch_state();
 
-       free(reflog_action);
+       strbuf_release(&msg);
 
        return update_ref_status;
 }

diff --git a/t/t1412-reflog-loop.sh b/t/t1412-reflog-loop.sh
index 7f519e5..647d888 100755 (executable)
--- a/t/t1412-reflog-loop.sh
+++ b/t/t1412-reflog-loop.sh
@@ -21,10 +21,10 @@ test_expect_success 'setup reflog with alternating commits' '
 
 test_expect_success 'reflog shows all entries' '
        cat >expect <<-\EOF
-               topic@{0} two: updating HEAD
-               topic@{1} one: updating HEAD
-               topic@{2} two: updating HEAD
-               topic@{3} one: updating HEAD
+               topic@{0} reset: moving to two
+               topic@{1} reset: moving to one
+               topic@{2} reset: moving to two
+               topic@{3} reset: moving to one
                topic@{4} branch: Created from HEAD
        EOF
        git log -g --format="%gd %gs" topic >actual &&