builtin-am: rerere support

git-am.sh will call git-rerere at the following events:

* "git rerere" when a three-way merge fails to record the conflicted
automerge results. Since 8389b52 (git-rerere: reuse recorded resolve.,
2006-01-28)

* Since cb6020b (Teach --[no-]rerere-autoupdate option to merge,
revert and friends, 2009-12-04), git-am.sh supports the
--[no-]rerere-autoupdate option as well, and would pass it to
git-rerere.

* "git rerere" when --resolved, to record the hand resolution. Since
f131dd4 (rerere: record (or avoid misrecording) resolved, skipped or
aborted rebase/am, 2006-12-08)

* "git rerere clear" when --skip-ing. Since f131dd4 (rerere: record (or
avoid misrecording) resolved, skipped or aborted rebase/am,
2006-12-08)

* "git rerere clear" when --abort-ing. Since 3e5057a (git am --abort,
2008-07-16)

Re-implement the above in builtin/am.c.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/am.c b/builtin/am.c
index c313e58dcdec0ea9086c3556301aba4f53766d5b..33d1f24d07bf12a350dc1e0c4eba952ba226400a 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -24,6 +24,7 @@
 #include "revision.h"
 #include "log-tree.h"
 #include "notes-utils.h"
+#include "rerere.h"
 
 /**
  * Returns 1 if the file is empty or does not exist, 0 otherwise.
@@ -114,6 +115,7 @@ struct am_state {
        const char *resolvemsg;
        int committer_date_is_author_date;
        int ignore_date;
+       int allow_rerere_autoupdate;
        const char *sign_commit;
        int rebasing;
 };
@@ -1312,6 +1314,7 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
                o.verbosity = 0;
 
        if (merge_recursive_generic(&o, our_tree, his_tree, 1, bases, &result)) {
+               rerere(state->allow_rerere_autoupdate);
                free(his_tree_name);
                return error(_("Failed to merge in the changes."));
        }
@@ -1531,6 +1534,8 @@ static void am_resolve(struct am_state *state)
                die_user_resolve(state);
        }
 
+       rerere(0);
+
        do_commit(state);
 
        am_next(state);
@@ -1630,6 +1635,21 @@ static int clean_index(const unsigned char *head, const unsigned char *remote)
        return 0;
 }
 
+/**
+ * Resets rerere's merge resolution metadata.
+ */
+static void am_rerere_clear(void)
+{
+       struct string_list merge_rr = STRING_LIST_INIT_DUP;
+       int fd = setup_rerere(&merge_rr, 0);
+
+       if (fd < 0)
+               return;
+
+       rerere_clear(&merge_rr);
+       string_list_clear(&merge_rr, 1);
+}
+
 /**
  * Resume the current am session by skipping the current patch.
  */
@@ -1637,6 +1657,8 @@ static void am_skip(struct am_state *state)
 {
        unsigned char head[GIT_SHA1_RAWSZ];
 
+       am_rerere_clear();
+
        if (get_sha1("HEAD", head))
                hashcpy(head, EMPTY_TREE_SHA1_BIN);
 
@@ -1694,6 +1716,8 @@ static void am_abort(struct am_state *state)
                return;
        }
 
+       am_rerere_clear();
+
        curr_branch = resolve_refdup("HEAD", 0, curr_head, NULL);
        has_curr_head = !is_null_sha1(curr_head);
        if (!has_curr_head)
@@ -1823,6 +1847,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                        N_("lie about committer date")),
                OPT_BOOL(0, "ignore-date", &state.ignore_date,
                        N_("use current timestamp for author date")),
+               OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
                { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
                  N_("GPG-sign commits"),
                  PARSE_OPT_OPTARG, NULL, (intptr_t) "" },