i18n: git-pull eval_gettext + die message
[gitweb.git] / notes-merge.c
index ab9885039ee00c8f847bb9cc9ab26e103cfd1cca..28046a998426e88dec9ad6ab431624bb41a81ce1 100644 (file)
@@ -1,11 +1,23 @@
 #include "cache.h"
 #include "commit.h"
 #include "refs.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "xdiff-interface.h"
+#include "ll-merge.h"
+#include "dir.h"
+#include "notes.h"
 #include "notes-merge.h"
+#include "strbuf.h"
+
+struct notes_merge_pair {
+       unsigned char obj[20], base[20], local[20], remote[20];
+};
 
 void init_notes_merge_options(struct notes_merge_options *o)
 {
        memset(o, 0, sizeof(struct notes_merge_options));
+       strbuf_init(&(o->commit_msg), 0);
        o->verbosity = NOTES_MERGE_VERBOSITY_DEFAULT;
 }
 
@@ -17,16 +29,539 @@ void init_notes_merge_options(struct notes_merge_options *o)
                } \
        } while (0)
 
+static int path_to_sha1(const char *path, unsigned char *sha1)
+{
+       char hex_sha1[40];
+       int i = 0;
+       while (*path && i < 40) {
+               if (*path != '/')
+                       hex_sha1[i++] = *path;
+               path++;
+       }
+       if (*path || i != 40)
+               return -1;
+       return get_sha1_hex(hex_sha1, sha1);
+}
+
+static int verify_notes_filepair(struct diff_filepair *p, unsigned char *sha1)
+{
+       switch (p->status) {
+       case DIFF_STATUS_MODIFIED:
+               assert(p->one->mode == p->two->mode);
+               assert(!is_null_sha1(p->one->sha1));
+               assert(!is_null_sha1(p->two->sha1));
+               break;
+       case DIFF_STATUS_ADDED:
+               assert(is_null_sha1(p->one->sha1));
+               break;
+       case DIFF_STATUS_DELETED:
+               assert(is_null_sha1(p->two->sha1));
+               break;
+       default:
+               return -1;
+       }
+       assert(!strcmp(p->one->path, p->two->path));
+       return path_to_sha1(p->one->path, sha1);
+}
+
+static struct notes_merge_pair *find_notes_merge_pair_pos(
+               struct notes_merge_pair *list, int len, unsigned char *obj,
+               int insert_new, int *occupied)
+{
+       /*
+        * Both diff_tree_remote() and diff_tree_local() tend to process
+        * merge_pairs in ascending order. Therefore, cache last returned
+        * index, and search sequentially from there until the appropriate
+        * position is found.
+        *
+        * Since inserts only happen from diff_tree_remote() (which mainly
+        * _appends_), we don't care that inserting into the middle of the
+        * list is expensive (using memmove()).
+        */
+       static int last_index;
+       int i = last_index < len ? last_index : len - 1;
+       int prev_cmp = 0, cmp = -1;
+       while (i >= 0 && i < len) {
+               cmp = hashcmp(obj, list[i].obj);
+               if (!cmp) /* obj belongs @ i */
+                       break;
+               else if (cmp < 0 && prev_cmp <= 0) /* obj belongs < i */
+                       i--;
+               else if (cmp < 0) /* obj belongs between i-1 and i */
+                       break;
+               else if (cmp > 0 && prev_cmp >= 0) /* obj belongs > i */
+                       i++;
+               else /* if (cmp > 0) */ { /* obj belongs between i and i+1 */
+                       i++;
+                       break;
+               }
+               prev_cmp = cmp;
+       }
+       if (i < 0)
+               i = 0;
+       /* obj belongs at, or immediately preceding, index i (0 <= i <= len) */
+
+       if (!cmp)
+               *occupied = 1;
+       else {
+               *occupied = 0;
+               if (insert_new && i < len) {
+                       memmove(list + i + 1, list + i,
+                               (len - i) * sizeof(struct notes_merge_pair));
+                       memset(list + i, 0, sizeof(struct notes_merge_pair));
+               }
+       }
+       last_index = i;
+       return list + i;
+}
+
+static unsigned char uninitialized[20] =
+       "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
+       "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff";
+
+static struct notes_merge_pair *diff_tree_remote(struct notes_merge_options *o,
+                                                const unsigned char *base,
+                                                const unsigned char *remote,
+                                                int *num_changes)
+{
+       struct diff_options opt;
+       struct notes_merge_pair *changes;
+       int i, len = 0;
+
+       trace_printf("\tdiff_tree_remote(base = %.7s, remote = %.7s)\n",
+              sha1_to_hex(base), sha1_to_hex(remote));
+
+       diff_setup(&opt);
+       DIFF_OPT_SET(&opt, RECURSIVE);
+       opt.output_format = DIFF_FORMAT_NO_OUTPUT;
+       if (diff_setup_done(&opt) < 0)
+               die("diff_setup_done failed");
+       diff_tree_sha1(base, remote, "", &opt);
+       diffcore_std(&opt);
+
+       changes = xcalloc(diff_queued_diff.nr, sizeof(struct notes_merge_pair));
+
+       for (i = 0; i < diff_queued_diff.nr; i++) {
+               struct diff_filepair *p = diff_queued_diff.queue[i];
+               struct notes_merge_pair *mp;
+               int occupied;
+               unsigned char obj[20];
+
+               if (verify_notes_filepair(p, obj)) {
+                       trace_printf("\t\tCannot merge entry '%s' (%c): "
+                              "%.7s -> %.7s. Skipping!\n", p->one->path,
+                              p->status, sha1_to_hex(p->one->sha1),
+                              sha1_to_hex(p->two->sha1));
+                       continue;
+               }
+               mp = find_notes_merge_pair_pos(changes, len, obj, 1, &occupied);
+               if (occupied) {
+                       /* We've found an addition/deletion pair */
+                       assert(!hashcmp(mp->obj, obj));
+                       if (is_null_sha1(p->one->sha1)) { /* addition */
+                               assert(is_null_sha1(mp->remote));
+                               hashcpy(mp->remote, p->two->sha1);
+                       } else if (is_null_sha1(p->two->sha1)) { /* deletion */
+                               assert(is_null_sha1(mp->base));
+                               hashcpy(mp->base, p->one->sha1);
+                       } else
+                               assert(!"Invalid existing change recorded");
+               } else {
+                       hashcpy(mp->obj, obj);
+                       hashcpy(mp->base, p->one->sha1);
+                       hashcpy(mp->local, uninitialized);
+                       hashcpy(mp->remote, p->two->sha1);
+                       len++;
+               }
+               trace_printf("\t\tStored remote change for %s: %.7s -> %.7s\n",
+                      sha1_to_hex(mp->obj), sha1_to_hex(mp->base),
+                      sha1_to_hex(mp->remote));
+       }
+       diff_flush(&opt);
+       diff_tree_release_paths(&opt);
+
+       *num_changes = len;
+       return changes;
+}
+
+static void diff_tree_local(struct notes_merge_options *o,
+                           struct notes_merge_pair *changes, int len,
+                           const unsigned char *base,
+                           const unsigned char *local)
+{
+       struct diff_options opt;
+       int i;
+
+       trace_printf("\tdiff_tree_local(len = %i, base = %.7s, local = %.7s)\n",
+              len, sha1_to_hex(base), sha1_to_hex(local));
+
+       diff_setup(&opt);
+       DIFF_OPT_SET(&opt, RECURSIVE);
+       opt.output_format = DIFF_FORMAT_NO_OUTPUT;
+       if (diff_setup_done(&opt) < 0)
+               die("diff_setup_done failed");
+       diff_tree_sha1(base, local, "", &opt);
+       diffcore_std(&opt);
+
+       for (i = 0; i < diff_queued_diff.nr; i++) {
+               struct diff_filepair *p = diff_queued_diff.queue[i];
+               struct notes_merge_pair *mp;
+               int match;
+               unsigned char obj[20];
+
+               if (verify_notes_filepair(p, obj)) {
+                       trace_printf("\t\tCannot merge entry '%s' (%c): "
+                              "%.7s -> %.7s. Skipping!\n", p->one->path,
+                              p->status, sha1_to_hex(p->one->sha1),
+                              sha1_to_hex(p->two->sha1));
+                       continue;
+               }
+               mp = find_notes_merge_pair_pos(changes, len, obj, 0, &match);
+               if (!match) {
+                       trace_printf("\t\tIgnoring local-only change for %s: "
+                              "%.7s -> %.7s\n", sha1_to_hex(obj),
+                              sha1_to_hex(p->one->sha1),
+                              sha1_to_hex(p->two->sha1));
+                       continue;
+               }
+
+               assert(!hashcmp(mp->obj, obj));
+               if (is_null_sha1(p->two->sha1)) { /* deletion */
+                       /*
+                        * Either this is a true deletion (1), or it is part
+                        * of an A/D pair (2), or D/A pair (3):
+                        *
+                        * (1) mp->local is uninitialized; set it to null_sha1
+                        * (2) mp->local is not uninitialized; don't touch it
+                        * (3) mp->local is uninitialized; set it to null_sha1
+                        *     (will be overwritten by following addition)
+                        */
+                       if (!hashcmp(mp->local, uninitialized))
+                               hashclr(mp->local);
+               } else if (is_null_sha1(p->one->sha1)) { /* addition */
+                       /*
+                        * Either this is a true addition (1), or it is part
+                        * of an A/D pair (2), or D/A pair (3):
+                        *
+                        * (1) mp->local is uninitialized; set to p->two->sha1
+                        * (2) mp->local is uninitialized; set to p->two->sha1
+                        * (3) mp->local is null_sha1;     set to p->two->sha1
+                        */
+                       assert(is_null_sha1(mp->local) ||
+                              !hashcmp(mp->local, uninitialized));
+                       hashcpy(mp->local, p->two->sha1);
+               } else { /* modification */
+                       /*
+                        * This is a true modification. p->one->sha1 shall
+                        * match mp->base, and mp->local shall be uninitialized.
+                        * Set mp->local to p->two->sha1.
+                        */
+                       assert(!hashcmp(p->one->sha1, mp->base));
+                       assert(!hashcmp(mp->local, uninitialized));
+                       hashcpy(mp->local, p->two->sha1);
+               }
+               trace_printf("\t\tStored local change for %s: %.7s -> %.7s\n",
+                      sha1_to_hex(mp->obj), sha1_to_hex(mp->base),
+                      sha1_to_hex(mp->local));
+       }
+       diff_flush(&opt);
+       diff_tree_release_paths(&opt);
+}
+
+static void check_notes_merge_worktree(struct notes_merge_options *o)
+{
+       if (!o->has_worktree) {
+               /*
+                * Must establish NOTES_MERGE_WORKTREE.
+                * Abort if NOTES_MERGE_WORKTREE already exists
+                */
+               if (file_exists(git_path(NOTES_MERGE_WORKTREE))) {
+                       if (advice_resolve_conflict)
+                               die("You have not concluded your previous "
+                                   "notes merge (%s exists).\nPlease, use "
+                                   "'git notes merge --commit' or 'git notes "
+                                   "merge --abort' to commit/abort the "
+                                   "previous merge before you start a new "
+                                   "notes merge.", git_path("NOTES_MERGE_*"));
+                       else
+                               die("You have not concluded your notes merge "
+                                   "(%s exists).", git_path("NOTES_MERGE_*"));
+               }
+
+               if (safe_create_leading_directories(git_path(
+                               NOTES_MERGE_WORKTREE "/.test")))
+                       die_errno("unable to create directory %s",
+                                 git_path(NOTES_MERGE_WORKTREE));
+               o->has_worktree = 1;
+       } else if (!file_exists(git_path(NOTES_MERGE_WORKTREE)))
+               /* NOTES_MERGE_WORKTREE should already be established */
+               die("missing '%s'. This should not happen",
+                   git_path(NOTES_MERGE_WORKTREE));
+}
+
+static void write_buf_to_worktree(const unsigned char *obj,
+                                 const char *buf, unsigned long size)
+{
+       int fd;
+       char *path = git_path(NOTES_MERGE_WORKTREE "/%s", sha1_to_hex(obj));
+       if (safe_create_leading_directories(path))
+               die_errno("unable to create directory for '%s'", path);
+       if (file_exists(path))
+               die("found existing file at '%s'", path);
+
+       fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0666);
+       if (fd < 0)
+               die_errno("failed to open '%s'", path);
+
+       while (size > 0) {
+               long ret = write_in_full(fd, buf, size);
+               if (ret < 0) {
+                       /* Ignore epipe */
+                       if (errno == EPIPE)
+                               break;
+                       die_errno("notes-merge");
+               } else if (!ret) {
+                       die("notes-merge: disk full?");
+               }
+               size -= ret;
+               buf += ret;
+       }
+
+       close(fd);
+}
+
+static void write_note_to_worktree(const unsigned char *obj,
+                                  const unsigned char *note)
+{
+       enum object_type type;
+       unsigned long size;
+       void *buf = read_sha1_file(note, &type, &size);
+
+       if (!buf)
+               die("cannot read note %s for object %s",
+                   sha1_to_hex(note), sha1_to_hex(obj));
+       if (type != OBJ_BLOB)
+               die("blob expected in note %s for object %s",
+                   sha1_to_hex(note), sha1_to_hex(obj));
+       write_buf_to_worktree(obj, buf, size);
+       free(buf);
+}
+
+static int ll_merge_in_worktree(struct notes_merge_options *o,
+                               struct notes_merge_pair *p)
+{
+       mmbuffer_t result_buf;
+       mmfile_t base, local, remote;
+       int status;
+
+       read_mmblob(&base, p->base);
+       read_mmblob(&local, p->local);
+       read_mmblob(&remote, p->remote);
+
+       status = ll_merge(&result_buf, sha1_to_hex(p->obj), &base, NULL,
+                         &local, o->local_ref, &remote, o->remote_ref, NULL);
+
+       free(base.ptr);
+       free(local.ptr);
+       free(remote.ptr);
+
+       if ((status < 0) || !result_buf.ptr)
+               die("Failed to execute internal merge");
+
+       write_buf_to_worktree(p->obj, result_buf.ptr, result_buf.size);
+       free(result_buf.ptr);
+
+       return status;
+}
+
+static int merge_one_change_manual(struct notes_merge_options *o,
+                                  struct notes_merge_pair *p,
+                                  struct notes_tree *t)
+{
+       const char *lref = o->local_ref ? o->local_ref : "local version";
+       const char *rref = o->remote_ref ? o->remote_ref : "remote version";
+
+       trace_printf("\t\t\tmerge_one_change_manual(obj = %.7s, base = %.7s, "
+              "local = %.7s, remote = %.7s)\n",
+              sha1_to_hex(p->obj), sha1_to_hex(p->base),
+              sha1_to_hex(p->local), sha1_to_hex(p->remote));
+
+       /* add "Conflicts:" section to commit message first time through */
+       if (!o->has_worktree)
+               strbuf_addstr(&(o->commit_msg), "\n\nConflicts:\n");
+
+       strbuf_addf(&(o->commit_msg), "\t%s\n", sha1_to_hex(p->obj));
+
+       OUTPUT(o, 2, "Auto-merging notes for %s", sha1_to_hex(p->obj));
+       check_notes_merge_worktree(o);
+       if (is_null_sha1(p->local)) {
+               /* D/F conflict, checkout p->remote */
+               assert(!is_null_sha1(p->remote));
+               OUTPUT(o, 1, "CONFLICT (delete/modify): Notes for object %s "
+                      "deleted in %s and modified in %s. Version from %s "
+                      "left in tree.", sha1_to_hex(p->obj), lref, rref, rref);
+               write_note_to_worktree(p->obj, p->remote);
+       } else if (is_null_sha1(p->remote)) {
+               /* D/F conflict, checkout p->local */
+               assert(!is_null_sha1(p->local));
+               OUTPUT(o, 1, "CONFLICT (delete/modify): Notes for object %s "
+                      "deleted in %s and modified in %s. Version from %s "
+                      "left in tree.", sha1_to_hex(p->obj), rref, lref, lref);
+               write_note_to_worktree(p->obj, p->local);
+       } else {
+               /* "regular" conflict, checkout result of ll_merge() */
+               const char *reason = "content";
+               if (is_null_sha1(p->base))
+                       reason = "add/add";
+               assert(!is_null_sha1(p->local));
+               assert(!is_null_sha1(p->remote));
+               OUTPUT(o, 1, "CONFLICT (%s): Merge conflict in notes for "
+                      "object %s", reason, sha1_to_hex(p->obj));
+               ll_merge_in_worktree(o, p);
+       }
+
+       trace_printf("\t\t\tremoving from partial merge result\n");
+       remove_note(t, p->obj);
+
+       return 1;
+}
+
+static int merge_one_change(struct notes_merge_options *o,
+                           struct notes_merge_pair *p, struct notes_tree *t)
+{
+       /*
+        * Return 0 if change is successfully resolved (stored in notes_tree).
+        * Return 1 is change results in a conflict (NOT stored in notes_tree,
+        * but instead written to NOTES_MERGE_WORKTREE with conflict markers).
+        */
+       switch (o->strategy) {
+       case NOTES_MERGE_RESOLVE_MANUAL:
+               return merge_one_change_manual(o, p, t);
+       case NOTES_MERGE_RESOLVE_OURS:
+               OUTPUT(o, 2, "Using local notes for %s", sha1_to_hex(p->obj));
+               /* nothing to do */
+               return 0;
+       case NOTES_MERGE_RESOLVE_THEIRS:
+               OUTPUT(o, 2, "Using remote notes for %s", sha1_to_hex(p->obj));
+               if (add_note(t, p->obj, p->remote, combine_notes_overwrite))
+                       die("BUG: combine_notes_overwrite failed");
+               return 0;
+       case NOTES_MERGE_RESOLVE_UNION:
+               OUTPUT(o, 2, "Concatenating local and remote notes for %s",
+                      sha1_to_hex(p->obj));
+               if (add_note(t, p->obj, p->remote, combine_notes_concatenate))
+                       die("failed to concatenate notes "
+                           "(combine_notes_concatenate)");
+               return 0;
+       case NOTES_MERGE_RESOLVE_CAT_SORT_UNIQ:
+               OUTPUT(o, 2, "Concatenating unique lines in local and remote "
+                      "notes for %s", sha1_to_hex(p->obj));
+               if (add_note(t, p->obj, p->remote, combine_notes_cat_sort_uniq))
+                       die("failed to concatenate notes "
+                           "(combine_notes_cat_sort_uniq)");
+               return 0;
+       }
+       die("Unknown strategy (%i).", o->strategy);
+}
+
+static int merge_changes(struct notes_merge_options *o,
+                        struct notes_merge_pair *changes, int *num_changes,
+                        struct notes_tree *t)
+{
+       int i, conflicts = 0;
+
+       trace_printf("\tmerge_changes(num_changes = %i)\n", *num_changes);
+       for (i = 0; i < *num_changes; i++) {
+               struct notes_merge_pair *p = changes + i;
+               trace_printf("\t\t%.7s: %.7s -> %.7s/%.7s\n",
+                      sha1_to_hex(p->obj), sha1_to_hex(p->base),
+                      sha1_to_hex(p->local), sha1_to_hex(p->remote));
+
+               if (!hashcmp(p->base, p->remote)) {
+                       /* no remote change; nothing to do */
+                       trace_printf("\t\t\tskipping (no remote change)\n");
+               } else if (!hashcmp(p->local, p->remote)) {
+                       /* same change in local and remote; nothing to do */
+                       trace_printf("\t\t\tskipping (local == remote)\n");
+               } else if (!hashcmp(p->local, uninitialized) ||
+                          !hashcmp(p->local, p->base)) {
+                       /* no local change; adopt remote change */
+                       trace_printf("\t\t\tno local change, adopted remote\n");
+                       if (add_note(t, p->obj, p->remote,
+                                    combine_notes_overwrite))
+                               die("BUG: combine_notes_overwrite failed");
+               } else {
+                       /* need file-level merge between local and remote */
+                       trace_printf("\t\t\tneed content-level merge\n");
+                       conflicts += merge_one_change(o, p, t);
+               }
+       }
+
+       return conflicts;
+}
+
+static int merge_from_diffs(struct notes_merge_options *o,
+                           const unsigned char *base,
+                           const unsigned char *local,
+                           const unsigned char *remote, struct notes_tree *t)
+{
+       struct notes_merge_pair *changes;
+       int num_changes, conflicts;
+
+       trace_printf("\tmerge_from_diffs(base = %.7s, local = %.7s, "
+              "remote = %.7s)\n", sha1_to_hex(base), sha1_to_hex(local),
+              sha1_to_hex(remote));
+
+       changes = diff_tree_remote(o, base, remote, &num_changes);
+       diff_tree_local(o, changes, num_changes, base, local);
+
+       conflicts = merge_changes(o, changes, &num_changes, t);
+       free(changes);
+
+       OUTPUT(o, 4, "Merge result: %i unmerged notes and a %s notes tree",
+              conflicts, t->dirty ? "dirty" : "clean");
+
+       return conflicts ? -1 : 1;
+}
+
+void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
+                        const char *msg, unsigned char *result_sha1)
+{
+       unsigned char tree_sha1[20];
+
+       assert(t->initialized);
+
+       if (write_notes_tree(t, tree_sha1))
+               die("Failed to write notes tree to database");
+
+       if (!parents) {
+               /* Deduce parent commit from t->ref */
+               unsigned char parent_sha1[20];
+               if (!read_ref(t->ref, parent_sha1)) {
+                       struct commit *parent = lookup_commit(parent_sha1);
+                       if (!parent || parse_commit(parent))
+                               die("Failed to find/parse commit %s", t->ref);
+                       commit_list_insert(parent, &parents);
+               }
+               /* else: t->ref points to nothing, assume root/orphan commit */
+       }
+
+       if (commit_tree(msg, tree_sha1, parents, result_sha1, NULL))
+               die("Failed to commit notes tree to database");
+}
+
 int notes_merge(struct notes_merge_options *o,
+               struct notes_tree *local_tree,
                unsigned char *result_sha1)
 {
        unsigned char local_sha1[20], remote_sha1[20];
        struct commit *local, *remote;
        struct commit_list *bases = NULL;
-       const unsigned char *base_sha1;
+       const unsigned char *base_sha1, *base_tree_sha1;
        int result = 0;
 
        assert(o->local_ref && o->remote_ref);
+       assert(!strcmp(o->local_ref, local_tree->ref));
        hashclr(result_sha1);
 
        trace_printf("notes_merge(o->local_ref = %s, o->remote_ref = %s)\n",
@@ -80,14 +615,17 @@ int notes_merge(struct notes_merge_options *o,
        bases = get_merge_bases(local, remote, 1);
        if (!bases) {
                base_sha1 = null_sha1;
+               base_tree_sha1 = EMPTY_TREE_SHA1_BIN;
                OUTPUT(o, 4, "No merge base found; doing history-less merge");
        } else if (!bases->next) {
                base_sha1 = bases->item->object.sha1;
+               base_tree_sha1 = bases->item->tree->object.sha1;
                OUTPUT(o, 4, "One merge base found (%.7s)",
                       sha1_to_hex(base_sha1));
        } else {
                /* TODO: How to handle multiple merge-bases? */
                base_sha1 = bases->item->object.sha1;
+               base_tree_sha1 = bases->item->tree->object.sha1;
                OUTPUT(o, 3, "Multiple merge bases found. Using the first "
                       "(%.7s)", sha1_to_hex(base_sha1));
        }
@@ -109,12 +647,91 @@ int notes_merge(struct notes_merge_options *o,
                goto found_result;
        }
 
-       /* TODO: */
-       result = error("notes_merge() cannot yet handle real merges.");
+       result = merge_from_diffs(o, base_tree_sha1, local->tree->object.sha1,
+                                 remote->tree->object.sha1, local_tree);
+
+       if (result != 0) { /* non-trivial merge (with or without conflicts) */
+               /* Commit (partial) result */
+               struct commit_list *parents = NULL;
+               commit_list_insert(remote, &parents); /* LIFO order */
+               commit_list_insert(local, &parents);
+               create_notes_commit(local_tree, parents, o->commit_msg.buf,
+                                   result_sha1);
+       }
 
 found_result:
        free_commit_list(bases);
+       strbuf_release(&(o->commit_msg));
        trace_printf("notes_merge(): result = %i, result_sha1 = %.7s\n",
               result, sha1_to_hex(result_sha1));
        return result;
 }
+
+int notes_merge_commit(struct notes_merge_options *o,
+                      struct notes_tree *partial_tree,
+                      struct commit *partial_commit,
+                      unsigned char *result_sha1)
+{
+       /*
+        * Iterate through files in .git/NOTES_MERGE_WORKTREE and add all
+        * found notes to 'partial_tree'. Write the updates notes tree to
+        * the DB, and commit the resulting tree object while reusing the
+        * commit message and parents from 'partial_commit'.
+        * Finally store the new commit object SHA1 into 'result_sha1'.
+        */
+       struct dir_struct dir;
+       const char *path = git_path(NOTES_MERGE_WORKTREE "/");
+       int path_len = strlen(path), i;
+       const char *msg = strstr(partial_commit->buffer, "\n\n");
+
+       OUTPUT(o, 3, "Committing notes in notes merge worktree at %.*s",
+              path_len - 1, path);
+
+       if (!msg || msg[2] == '\0')
+               die("partial notes commit has empty message");
+       msg += 2;
+
+       memset(&dir, 0, sizeof(dir));
+       read_directory(&dir, path, path_len, NULL);
+       for (i = 0; i < dir.nr; i++) {
+               struct dir_entry *ent = dir.entries[i];
+               struct stat st;
+               const char *relpath = ent->name + path_len;
+               unsigned char obj_sha1[20], blob_sha1[20];
+
+               if (ent->len - path_len != 40 || get_sha1_hex(relpath, obj_sha1)) {
+                       OUTPUT(o, 3, "Skipping non-SHA1 entry '%s'", ent->name);
+                       continue;
+               }
+
+               /* write file as blob, and add to partial_tree */
+               if (stat(ent->name, &st))
+                       die_errno("Failed to stat '%s'", ent->name);
+               if (index_path(blob_sha1, ent->name, &st, 1))
+                       die("Failed to write blob object from '%s'", ent->name);
+               if (add_note(partial_tree, obj_sha1, blob_sha1, NULL))
+                       die("Failed to add resolved note '%s' to notes tree",
+                           ent->name);
+               OUTPUT(o, 4, "Added resolved note for object %s: %s",
+                      sha1_to_hex(obj_sha1), sha1_to_hex(blob_sha1));
+       }
+
+       create_notes_commit(partial_tree, partial_commit->parents, msg,
+                           result_sha1);
+       OUTPUT(o, 4, "Finalized notes merge commit: %s",
+              sha1_to_hex(result_sha1));
+       return 0;
+}
+
+int notes_merge_abort(struct notes_merge_options *o)
+{
+       /* Remove .git/NOTES_MERGE_WORKTREE directory and all files within */
+       struct strbuf buf = STRBUF_INIT;
+       int ret;
+
+       strbuf_addstr(&buf, git_path(NOTES_MERGE_WORKTREE));
+       OUTPUT(o, 3, "Removing notes merge worktree at %s", buf.buf);
+       ret = remove_dir_recursively(&buf, 0);
+       strbuf_release(&buf);
+       return ret;
+}