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-rw-r--r--notes-merge.c737
1 files changed, 737 insertions, 0 deletions
diff --git a/notes-merge.c b/notes-merge.c
new file mode 100644
index 0000000..e1aaf43
--- /dev/null
+++ b/notes-merge.c
@@ -0,0 +1,737 @@
+#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;
+}
+
+#define OUTPUT(o, v, ...) \
+ do { \
+ if ((o)->verbosity >= (v)) { \
+ printf(__VA_ARGS__); \
+ puts(""); \
+ } \
+ } 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, *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",
+ o->local_ref, o->remote_ref);
+
+ /* Dereference o->local_ref into local_sha1 */
+ if (!resolve_ref(o->local_ref, local_sha1, 0, NULL))
+ die("Failed to resolve local notes ref '%s'", o->local_ref);
+ else if (!check_ref_format(o->local_ref) && is_null_sha1(local_sha1))
+ local = NULL; /* local_sha1 == null_sha1 indicates unborn ref */
+ else if (!(local = lookup_commit_reference(local_sha1)))
+ die("Could not parse local commit %s (%s)",
+ sha1_to_hex(local_sha1), o->local_ref);
+ trace_printf("\tlocal commit: %.7s\n", sha1_to_hex(local_sha1));
+
+ /* Dereference o->remote_ref into remote_sha1 */
+ if (get_sha1(o->remote_ref, remote_sha1)) {
+ /*
+ * Failed to get remote_sha1. If o->remote_ref looks like an
+ * unborn ref, perform the merge using an empty notes tree.
+ */
+ if (!check_ref_format(o->remote_ref)) {
+ hashclr(remote_sha1);
+ remote = NULL;
+ } else {
+ die("Failed to resolve remote notes ref '%s'",
+ o->remote_ref);
+ }
+ } else if (!(remote = lookup_commit_reference(remote_sha1))) {
+ die("Could not parse remote commit %s (%s)",
+ sha1_to_hex(remote_sha1), o->remote_ref);
+ }
+ trace_printf("\tremote commit: %.7s\n", sha1_to_hex(remote_sha1));
+
+ if (!local && !remote)
+ die("Cannot merge empty notes ref (%s) into empty notes ref "
+ "(%s)", o->remote_ref, o->local_ref);
+ if (!local) {
+ /* result == remote commit */
+ hashcpy(result_sha1, remote_sha1);
+ goto found_result;
+ }
+ if (!remote) {
+ /* result == local commit */
+ hashcpy(result_sha1, local_sha1);
+ goto found_result;
+ }
+ assert(local && remote);
+
+ /* Find merge bases */
+ 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));
+ }
+
+ OUTPUT(o, 4, "Merging remote commit %.7s into local commit %.7s with "
+ "merge-base %.7s", sha1_to_hex(remote->object.sha1),
+ sha1_to_hex(local->object.sha1), sha1_to_hex(base_sha1));
+
+ if (!hashcmp(remote->object.sha1, base_sha1)) {
+ /* Already merged; result == local commit */
+ OUTPUT(o, 2, "Already up-to-date!");
+ hashcpy(result_sha1, local->object.sha1);
+ goto found_result;
+ }
+ if (!hashcmp(local->object.sha1, base_sha1)) {
+ /* Fast-forward; result == remote commit */
+ OUTPUT(o, 2, "Fast-forward");
+ hashcpy(result_sha1, remote->object.sha1);
+ goto found_result;
+ }
+
+ 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, HASH_WRITE_OBJECT))
+ 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;
+}