cherry-pick: do not give irrelevant advice when cherry-pick punted

diff --git a/builtin/revert.c b/builtin/revert.c
index f697e6695374d06e7b08c9faac1ebaefe4ff31d7..e38fe0ce7ad2702c4a6edae262635c4f638ffcb6 100644 (file)
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -223,7 +223,7 @@ static void advise(const char *advice, ...)
        va_end(params);
 }
 
-static void print_advice(void)
+static void print_advice(int show_hint)
 {
        char *msg = getenv("GIT_CHERRY_PICK_HELP");
 
@@ -238,9 +238,11 @@ static void print_advice(void)
                return;
        }
 
-       advise("after resolving the conflicts, mark the corrected paths");
-       advise("with 'git add <paths>' or 'git rm <paths>'");
-       advise("and commit the result with 'git commit'");
+       if (show_hint) {
+               advise("after resolving the conflicts, mark the corrected paths");
+               advise("with 'git add <paths>' or 'git rm <paths>'");
+               advise("and commit the result with 'git commit'");
+       }
 }
 
 static void write_message(struct strbuf *msgbuf, const char *filename)
@@ -408,8 +410,6 @@ static int do_pick_commit(void)
        discard_cache();
 
        if (!commit->parents) {
-               if (action == REVERT)
-                       die (_("Cannot revert a root commit"));
                parent = NULL;
        }
        else if (commit->parents->next) {
@@ -467,7 +467,7 @@ static int do_pick_commit(void)
                strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
                strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 
-               if (commit->parents->next) {
+               if (commit->parents && commit->parents->next) {
                        strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
                        strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
                }
@@ -483,8 +483,6 @@ static int do_pick_commit(void)
                        strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
                        strbuf_addstr(&msgbuf, ")\n");
                }
-               if (!no_commit)
-                       write_cherry_pick_head();
        }
 
        if (!strategy || !strcmp(strategy, "recursive") || action == REVERT) {
@@ -505,13 +503,22 @@ static int do_pick_commit(void)
                free_commit_list(remotes);
        }
 
+       /*
+        * 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.
+        * However, if the merge did not even start, then we don't want to
+        * write it at all.
+        */
+       if (action == CHERRY_PICK && !no_commit && (res == 0 || res == 1))
+               write_cherry_pick_head();
+
        if (res) {
                error(action == REVERT
                      ? _("could not revert %s... %s")
                      : _("could not apply %s... %s"),
                      find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
                      msg.subject);
-               print_advice();
+               print_advice(res == 1);
                rerere(allow_rerere_auto);
        } else {
                if (!no_commit)