sequencer: make refs generated by the `label` command worktree-local
[gitweb.git] / sequencer.c
index 94f4831a0c3abdbe60c2abd135332ac6a293730f..e9297122633b83cce5bc880d366c36c6c1d8c574 100644 (file)
@@ -25,6 +25,8 @@
 #include "sigchain.h"
 #include "unpack-trees.h"
 #include "worktree.h"
+#include "oidmap.h"
+#include "oidset.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -2687,7 +2689,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
        struct commit *head_commit, *merge_commit, *i;
        struct commit_list *bases, *j, *reversed = NULL;
        struct merge_options o;
-       int merge_arg_len, oneline_offset, ret;
+       int merge_arg_len, oneline_offset, can_fast_forward, ret;
        static struct lock_file lock;
        const char *p;
 
@@ -2772,6 +2774,37 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len,
                }
        }
 
+       /*
+        * If HEAD is not identical to the first parent of the original merge
+        * commit, we cannot fast-forward.
+        */
+       can_fast_forward = opts->allow_ff && commit && commit->parents &&
+               !oidcmp(&commit->parents->item->object.oid,
+                       &head_commit->object.oid);
+
+       /*
+        * If the merge head is different from the original one, we cannot
+        * fast-forward.
+        */
+       if (can_fast_forward) {
+               struct commit_list *second_parent = commit->parents->next;
+
+               if (second_parent && !second_parent->next &&
+                   oidcmp(&merge_commit->object.oid,
+                          &second_parent->item->object.oid))
+                       can_fast_forward = 0;
+       }
+
+       if (can_fast_forward && commit->parents->next &&
+           !commit->parents->next->next &&
+           !oidcmp(&commit->parents->next->item->object.oid,
+                   &merge_commit->object.oid)) {
+               rollback_lock_file(&lock);
+               ret = fast_forward_to(&commit->object.oid,
+                                     &head_commit->object.oid, 0, opts);
+               goto leave_merge;
+       }
+
        write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ,
                      git_path_merge_head(), 0);
        write_message("no-ff", 5, git_path_merge_mode(), 0);
@@ -3417,6 +3450,343 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
        strbuf_release(&sob);
 }
 
+struct labels_entry {
+       struct hashmap_entry entry;
+       char label[FLEX_ARRAY];
+};
+
+static int labels_cmp(const void *fndata, const struct labels_entry *a,
+                     const struct labels_entry *b, const void *key)
+{
+       return key ? strcmp(a->label, key) : strcmp(a->label, b->label);
+}
+
+struct string_entry {
+       struct oidmap_entry entry;
+       char string[FLEX_ARRAY];
+};
+
+struct label_state {
+       struct oidmap commit2label;
+       struct hashmap labels;
+       struct strbuf buf;
+};
+
+static const char *label_oid(struct object_id *oid, const char *label,
+                            struct label_state *state)
+{
+       struct labels_entry *labels_entry;
+       struct string_entry *string_entry;
+       struct object_id dummy;
+       size_t len;
+       int i;
+
+       string_entry = oidmap_get(&state->commit2label, oid);
+       if (string_entry)
+               return string_entry->string;
+
+       /*
+        * For "uninteresting" commits, i.e. commits that are not to be
+        * rebased, and which can therefore not be labeled, we use a unique
+        * abbreviation of the commit name. This is slightly more complicated
+        * than calling find_unique_abbrev() because we also need to make
+        * sure that the abbreviation does not conflict with any other
+        * label.
+        *
+        * We disallow "interesting" commits to be labeled by a string that
+        * is a valid full-length hash, to ensure that we always can find an
+        * abbreviation for any uninteresting commit's names that does not
+        * clash with any other label.
+        */
+       if (!label) {
+               char *p;
+
+               strbuf_reset(&state->buf);
+               strbuf_grow(&state->buf, GIT_SHA1_HEXSZ);
+               label = p = state->buf.buf;
+
+               find_unique_abbrev_r(p, oid, default_abbrev);
+
+               /*
+                * We may need to extend the abbreviated hash so that there is
+                * no conflicting label.
+                */
+               if (hashmap_get_from_hash(&state->labels, strihash(p), p)) {
+                       size_t i = strlen(p) + 1;
+
+                       oid_to_hex_r(p, oid);
+                       for (; i < GIT_SHA1_HEXSZ; i++) {
+                               char save = p[i];
+                               p[i] = '\0';
+                               if (!hashmap_get_from_hash(&state->labels,
+                                                          strihash(p), p))
+                                       break;
+                               p[i] = save;
+                       }
+               }
+       } else if (((len = strlen(label)) == GIT_SHA1_RAWSZ &&
+                   !get_oid_hex(label, &dummy)) ||
+                  (len == 1 && *label == '#') ||
+                  hashmap_get_from_hash(&state->labels,
+                                        strihash(label), label)) {
+               /*
+                * If the label already exists, or if the label is a valid full
+                * OID, or the label is a '#' (which we use as a separator
+                * between merge heads and oneline), we append a dash and a
+                * number to make it unique.
+                */
+               struct strbuf *buf = &state->buf;
+
+               strbuf_reset(buf);
+               strbuf_add(buf, label, len);
+
+               for (i = 2; ; i++) {
+                       strbuf_setlen(buf, len);
+                       strbuf_addf(buf, "-%d", i);
+                       if (!hashmap_get_from_hash(&state->labels,
+                                                  strihash(buf->buf),
+                                                  buf->buf))
+                               break;
+               }
+
+               label = buf->buf;
+       }
+
+       FLEX_ALLOC_STR(labels_entry, label, label);
+       hashmap_entry_init(labels_entry, strihash(label));
+       hashmap_add(&state->labels, labels_entry);
+
+       FLEX_ALLOC_STR(string_entry, string, label);
+       oidcpy(&string_entry->entry.oid, oid);
+       oidmap_put(&state->commit2label, string_entry);
+
+       return string_entry->string;
+}
+
+static int make_script_with_merges(struct pretty_print_context *pp,
+                                  struct rev_info *revs, FILE *out,
+                                  unsigned flags)
+{
+       int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
+       struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
+       struct strbuf label = STRBUF_INIT;
+       struct commit_list *commits = NULL, **tail = &commits, *iter;
+       struct commit_list *tips = NULL, **tips_tail = &tips;
+       struct commit *commit;
+       struct oidmap commit2todo = OIDMAP_INIT;
+       struct string_entry *entry;
+       struct oidset interesting = OIDSET_INIT, child_seen = OIDSET_INIT,
+               shown = OIDSET_INIT;
+       struct label_state state = { OIDMAP_INIT, { NULL }, STRBUF_INIT };
+
+       int abbr = flags & TODO_LIST_ABBREVIATE_CMDS;
+       const char *cmd_pick = abbr ? "p" : "pick",
+               *cmd_label = abbr ? "l" : "label",
+               *cmd_reset = abbr ? "t" : "reset",
+               *cmd_merge = abbr ? "m" : "merge";
+
+       oidmap_init(&commit2todo, 0);
+       oidmap_init(&state.commit2label, 0);
+       hashmap_init(&state.labels, (hashmap_cmp_fn) labels_cmp, NULL, 0);
+       strbuf_init(&state.buf, 32);
+
+       if (revs->cmdline.nr && (revs->cmdline.rev[0].flags & BOTTOM)) {
+               struct object_id *oid = &revs->cmdline.rev[0].item->oid;
+               FLEX_ALLOC_STR(entry, string, "onto");
+               oidcpy(&entry->entry.oid, oid);
+               oidmap_put(&state.commit2label, entry);
+       }
+
+       /*
+        * First phase:
+        * - get onelines for all commits
+        * - gather all branch tips (i.e. 2nd or later parents of merges)
+        * - label all branch tips
+        */
+       while ((commit = get_revision(revs))) {
+               struct commit_list *to_merge;
+               int is_octopus;
+               const char *p1, *p2;
+               struct object_id *oid;
+               int is_empty;
+
+               tail = &commit_list_insert(commit, tail)->next;
+               oidset_insert(&interesting, &commit->object.oid);
+
+               is_empty = is_original_commit_empty(commit);
+               if (!is_empty && (commit->object.flags & PATCHSAME))
+                       continue;
+
+               strbuf_reset(&oneline);
+               pretty_print_commit(pp, commit, &oneline);
+
+               to_merge = commit->parents ? commit->parents->next : NULL;
+               if (!to_merge) {
+                       /* non-merge commit: easy case */
+                       strbuf_reset(&buf);
+                       if (!keep_empty && is_empty)
+                               strbuf_addf(&buf, "%c ", comment_line_char);
+                       strbuf_addf(&buf, "%s %s %s", cmd_pick,
+                                   oid_to_hex(&commit->object.oid),
+                                   oneline.buf);
+
+                       FLEX_ALLOC_STR(entry, string, buf.buf);
+                       oidcpy(&entry->entry.oid, &commit->object.oid);
+                       oidmap_put(&commit2todo, entry);
+
+                       continue;
+               }
+
+               is_octopus = to_merge && to_merge->next;
+
+               if (is_octopus)
+                       BUG("Octopus merges not yet supported");
+
+               /* Create a label */
+               strbuf_reset(&label);
+               if (skip_prefix(oneline.buf, "Merge ", &p1) &&
+                   (p1 = strchr(p1, '\'')) &&
+                   (p2 = strchr(++p1, '\'')))
+                       strbuf_add(&label, p1, p2 - p1);
+               else if (skip_prefix(oneline.buf, "Merge pull request ",
+                                    &p1) &&
+                        (p1 = strstr(p1, " from ")))
+                       strbuf_addstr(&label, p1 + strlen(" from "));
+               else
+                       strbuf_addbuf(&label, &oneline);
+
+               for (p1 = label.buf; *p1; p1++)
+                       if (isspace(*p1))
+                               *(char *)p1 = '-';
+
+               strbuf_reset(&buf);
+               strbuf_addf(&buf, "%s -C %s",
+                           cmd_merge, oid_to_hex(&commit->object.oid));
+
+               /* label the tip of merged branch */
+               oid = &to_merge->item->object.oid;
+               strbuf_addch(&buf, ' ');
+
+               if (!oidset_contains(&interesting, oid))
+                       strbuf_addstr(&buf, label_oid(oid, NULL, &state));
+               else {
+                       tips_tail = &commit_list_insert(to_merge->item,
+                                                       tips_tail)->next;
+
+                       strbuf_addstr(&buf, label_oid(oid, label.buf, &state));
+               }
+               strbuf_addf(&buf, " # %s", oneline.buf);
+
+               FLEX_ALLOC_STR(entry, string, buf.buf);
+               oidcpy(&entry->entry.oid, &commit->object.oid);
+               oidmap_put(&commit2todo, entry);
+       }
+
+       /*
+        * Second phase:
+        * - label branch points
+        * - add HEAD to the branch tips
+        */
+       for (iter = commits; iter; iter = iter->next) {
+               struct commit_list *parent = iter->item->parents;
+               for (; parent; parent = parent->next) {
+                       struct object_id *oid = &parent->item->object.oid;
+                       if (!oidset_contains(&interesting, oid))
+                               continue;
+                       if (!oidset_contains(&child_seen, oid))
+                               oidset_insert(&child_seen, oid);
+                       else
+                               label_oid(oid, "branch-point", &state);
+               }
+
+               /* Add HEAD as implict "tip of branch" */
+               if (!iter->next)
+                       tips_tail = &commit_list_insert(iter->item,
+                                                       tips_tail)->next;
+       }
+
+       /*
+        * Third phase: output the todo list. This is a bit tricky, as we
+        * want to avoid jumping back and forth between revisions. To
+        * accomplish that goal, we walk backwards from the branch tips,
+        * gathering commits not yet shown, reversing the list on the fly,
+        * then outputting that list (labeling revisions as needed).
+        */
+       fprintf(out, "%s onto\n", cmd_label);
+       for (iter = tips; iter; iter = iter->next) {
+               struct commit_list *list = NULL, *iter2;
+
+               commit = iter->item;
+               if (oidset_contains(&shown, &commit->object.oid))
+                       continue;
+               entry = oidmap_get(&state.commit2label, &commit->object.oid);
+
+               if (entry)
+                       fprintf(out, "\n# Branch %s\n", entry->string);
+               else
+                       fprintf(out, "\n");
+
+               while (oidset_contains(&interesting, &commit->object.oid) &&
+                      !oidset_contains(&shown, &commit->object.oid)) {
+                       commit_list_insert(commit, &list);
+                       if (!commit->parents) {
+                               commit = NULL;
+                               break;
+                       }
+                       commit = commit->parents->item;
+               }
+
+               if (!commit)
+                       fprintf(out, "%s onto\n", cmd_reset);
+               else {
+                       const char *to = NULL;
+
+                       entry = oidmap_get(&state.commit2label,
+                                          &commit->object.oid);
+                       if (entry)
+                               to = entry->string;
+
+                       if (!to || !strcmp(to, "onto"))
+                               fprintf(out, "%s onto\n", cmd_reset);
+                       else {
+                               strbuf_reset(&oneline);
+                               pretty_print_commit(pp, commit, &oneline);
+                               fprintf(out, "%s %s # %s\n",
+                                       cmd_reset, to, oneline.buf);
+                       }
+               }
+
+               for (iter2 = list; iter2; iter2 = iter2->next) {
+                       struct object_id *oid = &iter2->item->object.oid;
+                       entry = oidmap_get(&commit2todo, oid);
+                       /* only show if not already upstream */
+                       if (entry)
+                               fprintf(out, "%s\n", entry->string);
+                       entry = oidmap_get(&state.commit2label, oid);
+                       if (entry)
+                               fprintf(out, "%s %s\n",
+                                       cmd_label, entry->string);
+                       oidset_insert(&shown, oid);
+               }
+
+               free_commit_list(list);
+       }
+
+       free_commit_list(commits);
+       free_commit_list(tips);
+
+       strbuf_release(&label);
+       strbuf_release(&oneline);
+       strbuf_release(&buf);
+
+       oidmap_free(&commit2todo, 1);
+       oidmap_free(&state.commit2label, 1);
+       hashmap_free(&state.labels, 1);
+       strbuf_release(&state.buf);
+
+       return 0;
+}
+
 int sequencer_make_script(FILE *out, int argc, const char **argv,
                          unsigned flags)
 {
@@ -3427,10 +3797,12 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
        struct commit *commit;
        int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
        const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick";
+       int rebase_merges = flags & TODO_LIST_REBASE_MERGES;
 
        init_revisions(&revs, NULL);
        revs.verbose_header = 1;
-       revs.max_parents = 1;
+       if (!rebase_merges)
+               revs.max_parents = 1;
        revs.cherry_mark = 1;
        revs.limited = 1;
        revs.reverse = 1;
@@ -3455,6 +3827,9 @@ int sequencer_make_script(FILE *out, int argc, const char **argv,
        if (prepare_revision_walk(&revs) < 0)
                return error(_("make_script: error preparing revisions"));
 
+       if (rebase_merges)
+               return make_script_with_merges(&pp, &revs, out, flags);
+
        while ((commit = get_revision(&revs))) {
                int is_empty  = is_original_commit_empty(commit);