Merge branch 'rj/tap-fix'
[gitweb.git] / commit.c
index 73b7e00292ba2de33fa43b5f028fd807a460af34..0ea441d13b1430231f30d9524aed88b9719290b6 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -6,6 +6,8 @@
 #include "diff.h"
 #include "revision.h"
 #include "notes.h"
+#include "gpg-interface.h"
+#include "mergesort.h"
 
 int save_commit_buffer = 1;
 
@@ -66,7 +68,7 @@ struct commit *lookup_commit_reference_by_name(const char *name)
        unsigned char sha1[20];
        struct commit *commit;
 
-       if (get_sha1(name, sha1))
+       if (get_sha1_committish(name, sha1))
                return NULL;
        commit = lookup_commit_reference(sha1);
        if (!commit || parse_commit(commit))
@@ -389,15 +391,31 @@ struct commit_list * commit_list_insert_by_date(struct commit *item, struct comm
        return commit_list_insert(item, pp);
 }
 
+static int commit_list_compare_by_date(const void *a, const void *b)
+{
+       unsigned long a_date = ((const struct commit_list *)a)->item->date;
+       unsigned long b_date = ((const struct commit_list *)b)->item->date;
+       if (a_date < b_date)
+               return 1;
+       if (a_date > b_date)
+               return -1;
+       return 0;
+}
+
+static void *commit_list_get_next(const void *a)
+{
+       return ((const struct commit_list *)a)->next;
+}
+
+static void commit_list_set_next(void *a, void *next)
+{
+       ((struct commit_list *)a)->next = next;
+}
 
 void commit_list_sort_by_date(struct commit_list **list)
 {
-       struct commit_list *ret = NULL;
-       while (*list) {
-               commit_list_insert_by_date((*list)->item, &ret);
-               *list = (*list)->next;
-       }
-       *list = ret;
+       *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
+                               commit_list_compare_by_date);
 }
 
 struct commit *pop_most_recent_commit(struct commit_list **list,
@@ -421,7 +439,8 @@ struct commit *pop_most_recent_commit(struct commit_list **list,
        return ret;
 }
 
-void clear_commit_marks(struct commit *commit, unsigned int mark)
+static void clear_commit_marks_1(struct commit_list **plist,
+                                struct commit *commit, unsigned int mark)
 {
        while (commit) {
                struct commit_list *parents;
@@ -436,12 +455,20 @@ void clear_commit_marks(struct commit *commit, unsigned int mark)
                        return;
 
                while ((parents = parents->next))
-                       clear_commit_marks(parents->item, mark);
+                       commit_list_insert(parents->item, plist);
 
                commit = commit->parents->item;
        }
 }
 
+void clear_commit_marks(struct commit *commit, unsigned int mark)
+{
+       struct commit_list *list = NULL;
+       commit_list_insert(commit, &list);
+       while (list)
+               clear_commit_marks_1(&list, pop_commit(&list), mark);
+}
+
 void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
 {
        struct object *object;
@@ -580,28 +607,12 @@ static struct commit *interesting(struct commit_list *list)
        return NULL;
 }
 
-static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
+static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
 {
        struct commit_list *list = NULL;
        struct commit_list *result = NULL;
        int i;
 
-       for (i = 0; i < n; i++) {
-               if (one == twos[i])
-                       /*
-                        * We do not mark this even with RESULT so we do not
-                        * have to clean it up.
-                        */
-                       return commit_list_insert(one, &result);
-       }
-
-       if (parse_commit(one))
-               return NULL;
-       for (i = 0; i < n; i++) {
-               if (parse_commit(twos[i]))
-                       return NULL;
-       }
-
        one->object.flags |= PARENT1;
        commit_list_insert_by_date(one, &list);
        for (i = 0; i < n; i++) {
@@ -642,9 +653,34 @@ static struct commit_list *merge_bases_many(struct commit *one, int n, struct co
                }
        }
 
-       /* Clean up the result to remove stale ones */
        free_commit_list(list);
-       list = result; result = NULL;
+       return result;
+}
+
+static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
+{
+       struct commit_list *list = NULL;
+       struct commit_list *result = NULL;
+       int i;
+
+       for (i = 0; i < n; i++) {
+               if (one == twos[i])
+                       /*
+                        * We do not mark this even with RESULT so we do not
+                        * have to clean it up.
+                        */
+                       return commit_list_insert(one, &result);
+       }
+
+       if (parse_commit(one))
+               return NULL;
+       for (i = 0; i < n; i++) {
+               if (parse_commit(twos[i]))
+                       return NULL;
+       }
+
+       list = paint_down_to_common(one, n, twos);
+
        while (list) {
                struct commit_list *next = list->next;
                if (!(list->item->object.flags & STALE))
@@ -682,6 +718,60 @@ struct commit_list *get_octopus_merge_bases(struct commit_list *in)
        return ret;
 }
 
+static int remove_redundant(struct commit **array, int cnt)
+{
+       /*
+        * Some commit in the array may be an ancestor of
+        * another commit.  Move such commit to the end of
+        * the array, and return the number of commits that
+        * are independent from each other.
+        */
+       struct commit **work;
+       unsigned char *redundant;
+       int *filled_index;
+       int i, j, filled;
+
+       work = xcalloc(cnt, sizeof(*work));
+       redundant = xcalloc(cnt, 1);
+       filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
+
+       for (i = 0; i < cnt; i++) {
+               struct commit_list *common;
+
+               if (redundant[i])
+                       continue;
+               for (j = filled = 0; j < cnt; j++) {
+                       if (i == j || redundant[j])
+                               continue;
+                       filled_index[filled] = j;
+                       work[filled++] = array[j];
+               }
+               common = paint_down_to_common(array[i], filled, work);
+               if (array[i]->object.flags & PARENT2)
+                       redundant[i] = 1;
+               for (j = 0; j < filled; j++)
+                       if (work[j]->object.flags & PARENT1)
+                               redundant[filled_index[j]] = 1;
+               clear_commit_marks(array[i], all_flags);
+               for (j = 0; j < filled; j++)
+                       clear_commit_marks(work[j], all_flags);
+               free_commit_list(common);
+       }
+
+       /* Now collect the result */
+       memcpy(work, array, sizeof(*array) * cnt);
+       for (i = filled = 0; i < cnt; i++)
+               if (!redundant[i])
+                       array[filled++] = work[i];
+       for (j = filled, i = 0; i < cnt; i++)
+               if (redundant[i])
+                       array[j++] = work[i];
+       free(work);
+       free(redundant);
+       free(filled_index);
+       return filled;
+}
+
 struct commit_list *get_merge_bases_many(struct commit *one,
                                         int n,
                                         struct commit **twos,
@@ -690,7 +780,7 @@ struct commit_list *get_merge_bases_many(struct commit *one,
        struct commit_list *list;
        struct commit **rslt;
        struct commit_list *result;
-       int cnt, i, j;
+       int cnt, i;
 
        result = merge_bases_many(one, n, twos);
        for (i = 0; i < n; i++) {
@@ -721,28 +811,11 @@ struct commit_list *get_merge_bases_many(struct commit *one,
        clear_commit_marks(one, all_flags);
        for (i = 0; i < n; i++)
                clear_commit_marks(twos[i], all_flags);
-       for (i = 0; i < cnt - 1; i++) {
-               for (j = i+1; j < cnt; j++) {
-                       if (!rslt[i] || !rslt[j])
-                               continue;
-                       result = merge_bases_many(rslt[i], 1, &rslt[j]);
-                       clear_commit_marks(rslt[i], all_flags);
-                       clear_commit_marks(rslt[j], all_flags);
-                       for (list = result; list; list = list->next) {
-                               if (rslt[i] == list->item)
-                                       rslt[i] = NULL;
-                               if (rslt[j] == list->item)
-                                       rslt[j] = NULL;
-                       }
-               }
-       }
 
-       /* Surviving ones in rslt[] are the independent results */
+       cnt = remove_redundant(rslt, cnt);
        result = NULL;
-       for (i = 0; i < cnt; i++) {
-               if (rslt[i])
-                       commit_list_insert_by_date(rslt[i], &result);
-       }
+       for (i = 0; i < cnt; i++)
+               commit_list_insert_by_date(rslt[i], &result);
        free(rslt);
        return result;
 }
@@ -753,6 +826,9 @@ struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
        return get_merge_bases_many(one, 1, &two, cleanup);
 }
 
+/*
+ * Is "commit" a decendant of one of the elements on the "with_commit" list?
+ */
 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 {
        if (!with_commit)
@@ -762,28 +838,28 @@ int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
 
                other = with_commit->item;
                with_commit = with_commit->next;
-               if (in_merge_bases(other, &commit, 1))
+               if (in_merge_bases(other, commit))
                        return 1;
        }
        return 0;
 }
 
-int in_merge_bases(struct commit *commit, struct commit **reference, int num)
+/*
+ * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
+ */
+int in_merge_bases(struct commit *commit, struct commit *reference)
 {
-       struct commit_list *bases, *b;
+       struct commit_list *bases;
        int ret = 0;
 
-       if (num == 1)
-               bases = get_merge_bases(commit, *reference, 1);
-       else
-               die("not yet");
-       for (b = bases; b; b = b->next) {
-               if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
-                       ret = 1;
-                       break;
-               }
-       }
+       if (parse_commit(commit) || parse_commit(reference))
+               return ret;
 
+       bases = paint_down_to_common(commit, 1, &reference);
+       if (commit->object.flags & PARENT2)
+               ret = 1;
+       clear_commit_marks(commit, all_flags);
+       clear_commit_marks(reference, all_flags);
        free_commit_list(bases);
        return ret;
 }
@@ -792,62 +868,372 @@ struct commit_list *reduce_heads(struct commit_list *heads)
 {
        struct commit_list *p;
        struct commit_list *result = NULL, **tail = &result;
-       struct commit **other;
-       size_t num_head, num_other;
+       struct commit **array;
+       int num_head, i;
 
        if (!heads)
                return NULL;
 
-       /* Avoid unnecessary reallocations */
-       for (p = heads, num_head = 0; p; p = p->next)
+       /* Uniquify */
+       for (p = heads; p; p = p->next)
+               p->item->object.flags &= ~STALE;
+       for (p = heads, num_head = 0; p; p = p->next) {
+               if (p->item->object.flags & STALE)
+                       continue;
+               p->item->object.flags |= STALE;
                num_head++;
-       other = xcalloc(sizeof(*other), num_head);
+       }
+       array = xcalloc(sizeof(*array), num_head);
+       for (p = heads, i = 0; p; p = p->next) {
+               if (p->item->object.flags & STALE) {
+                       array[i++] = p->item;
+                       p->item->object.flags &= ~STALE;
+               }
+       }
+       num_head = remove_redundant(array, num_head);
+       for (i = 0; i < num_head; i++)
+               tail = &commit_list_insert(array[i], tail)->next;
+       return result;
+}
 
-       /* For each commit, see if it can be reached by others */
-       for (p = heads; p; p = p->next) {
-               struct commit_list *q, *base;
+static const char gpg_sig_header[] = "gpgsig";
+static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
 
-               /* Do we already have this in the result? */
-               for (q = result; q; q = q->next)
-                       if (p->item == q->item)
-                               break;
-               if (q)
-                       continue;
+static int do_sign_commit(struct strbuf *buf, const char *keyid)
+{
+       struct strbuf sig = STRBUF_INIT;
+       int inspos, copypos;
 
-               num_other = 0;
-               for (q = heads; q; q = q->next) {
-                       if (p->item == q->item)
-                               continue;
-                       other[num_other++] = q->item;
+       /* find the end of the header */
+       inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
+
+       if (!keyid || !*keyid)
+               keyid = get_signing_key();
+       if (sign_buffer(buf, &sig, keyid)) {
+               strbuf_release(&sig);
+               return -1;
+       }
+
+       for (copypos = 0; sig.buf[copypos]; ) {
+               const char *bol = sig.buf + copypos;
+               const char *eol = strchrnul(bol, '\n');
+               int len = (eol - bol) + !!*eol;
+
+               if (!copypos) {
+                       strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
+                       inspos += gpg_sig_header_len;
                }
-               if (num_other)
-                       base = get_merge_bases_many(p->item, num_other, other, 1);
-               else
-                       base = NULL;
+               strbuf_insert(buf, inspos++, " ", 1);
+               strbuf_insert(buf, inspos, bol, len);
+               inspos += len;
+               copypos += len;
+       }
+       strbuf_release(&sig);
+       return 0;
+}
+
+int parse_signed_commit(const unsigned char *sha1,
+                       struct strbuf *payload, struct strbuf *signature)
+{
+       unsigned long size;
+       enum object_type type;
+       char *buffer = read_sha1_file(sha1, &type, &size);
+       int in_signature, saw_signature = -1;
+       char *line, *tail;
+
+       if (!buffer || type != OBJ_COMMIT)
+               goto cleanup;
+
+       line = buffer;
+       tail = buffer + size;
+       in_signature = 0;
+       saw_signature = 0;
+       while (line < tail) {
+               const char *sig = NULL;
+               char *next = memchr(line, '\n', tail - line);
+
+               next = next ? next + 1 : tail;
+               if (in_signature && line[0] == ' ')
+                       sig = line + 1;
+               else if (!prefixcmp(line, gpg_sig_header) &&
+                        line[gpg_sig_header_len] == ' ')
+                       sig = line + gpg_sig_header_len + 1;
+               if (sig) {
+                       strbuf_add(signature, sig, next - sig);
+                       saw_signature = 1;
+                       in_signature = 1;
+               } else {
+                       if (*line == '\n')
+                               /* dump the whole remainder of the buffer */
+                               next = tail;
+                       strbuf_add(payload, line, next - line);
+                       in_signature = 0;
+               }
+               line = next;
+       }
+ cleanup:
+       free(buffer);
+       return saw_signature;
+}
+
+static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
+{
+       struct merge_remote_desc *desc;
+       struct commit_extra_header *mergetag;
+       char *buf;
+       unsigned long size, len;
+       enum object_type type;
+
+       desc = merge_remote_util(parent);
+       if (!desc || !desc->obj)
+               return;
+       buf = read_sha1_file(desc->obj->sha1, &type, &size);
+       if (!buf || type != OBJ_TAG)
+               goto free_return;
+       len = parse_signature(buf, size);
+       if (size == len)
+               goto free_return;
+       /*
+        * We could verify this signature and either omit the tag when
+        * it does not validate, but the integrator may not have the
+        * public key of the signer of the tag he is merging, while a
+        * later auditor may have it while auditing, so let's not run
+        * verify-signed-buffer here for now...
+        *
+        * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
+        *      warn("warning: signed tag unverified.");
+        */
+       mergetag = xcalloc(1, sizeof(*mergetag));
+       mergetag->key = xstrdup("mergetag");
+       mergetag->value = buf;
+       mergetag->len = size;
+
+       **tail = mergetag;
+       *tail = &mergetag->next;
+       return;
+
+free_return:
+       free(buf);
+}
+
+void append_merge_tag_headers(struct commit_list *parents,
+                             struct commit_extra_header ***tail)
+{
+       while (parents) {
+               struct commit *parent = parents->item;
+               handle_signed_tag(parent, tail);
+               parents = parents->next;
+       }
+}
+
+static void add_extra_header(struct strbuf *buffer,
+                            struct commit_extra_header *extra)
+{
+       strbuf_addstr(buffer, extra->key);
+       if (extra->len)
+               strbuf_add_lines(buffer, " ", extra->value, extra->len);
+       else
+               strbuf_addch(buffer, '\n');
+}
+
+struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
+                                                     const char **exclude)
+{
+       struct commit_extra_header *extra = NULL;
+       unsigned long size;
+       enum object_type type;
+       char *buffer = read_sha1_file(commit->object.sha1, &type, &size);
+       if (buffer && type == OBJ_COMMIT)
+               extra = read_commit_extra_header_lines(buffer, size, exclude);
+       free(buffer);
+       return extra;
+}
+
+static inline int standard_header_field(const char *field, size_t len)
+{
+       return ((len == 4 && !memcmp(field, "tree ", 5)) ||
+               (len == 6 && !memcmp(field, "parent ", 7)) ||
+               (len == 6 && !memcmp(field, "author ", 7)) ||
+               (len == 9 && !memcmp(field, "committer ", 10)) ||
+               (len == 8 && !memcmp(field, "encoding ", 9)));
+}
+
+static int excluded_header_field(const char *field, size_t len, const char **exclude)
+{
+       if (!exclude)
+               return 0;
+
+       while (*exclude) {
+               size_t xlen = strlen(*exclude);
+               if (len == xlen &&
+                   !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
+                       return 1;
+               exclude++;
+       }
+       return 0;
+}
+
+struct commit_extra_header *read_commit_extra_header_lines(const char *buffer, size_t size,
+                                                          const char **exclude)
+{
+       struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
+       const char *line, *next, *eof, *eob;
+       struct strbuf buf = STRBUF_INIT;
+
+       for (line = buffer, eob = line + size;
+            line < eob && *line != '\n';
+            line = next) {
+               next = memchr(line, '\n', eob - line);
+               next = next ? next + 1 : eob;
+               if (*line == ' ') {
+                       /* continuation */
+                       if (it)
+                               strbuf_add(&buf, line + 1, next - (line + 1));
+                       continue;
+               }
+               if (it)
+                       it->value = strbuf_detach(&buf, &it->len);
+               strbuf_reset(&buf);
+               it = NULL;
+
+               eof = strchr(line, ' ');
+               if (next <= eof)
+                       eof = next;
+
+               if (standard_header_field(line, eof - line) ||
+                   excluded_header_field(line, eof - line, exclude))
+                       continue;
+
+               it = xcalloc(1, sizeof(*it));
+               it->key = xmemdupz(line, eof-line);
+               *tail = it;
+               tail = &it->next;
+               if (eof + 1 < next)
+                       strbuf_add(&buf, eof + 1, next - (eof + 1));
+       }
+       if (it)
+               it->value = strbuf_detach(&buf, &it->len);
+       return extra;
+}
+
+void free_commit_extra_headers(struct commit_extra_header *extra)
+{
+       while (extra) {
+               struct commit_extra_header *next = extra->next;
+               free(extra->key);
+               free(extra->value);
+               free(extra);
+               extra = next;
+       }
+}
+
+int commit_tree(const struct strbuf *msg, unsigned char *tree,
+               struct commit_list *parents, unsigned char *ret,
+               const char *author, const char *sign_commit)
+{
+       struct commit_extra_header *extra = NULL, **tail = &extra;
+       int result;
+
+       append_merge_tag_headers(parents, &tail);
+       result = commit_tree_extended(msg, tree, parents, ret,
+                                     author, sign_commit, extra);
+       free_commit_extra_headers(extra);
+       return result;
+}
+
+static int find_invalid_utf8(const char *buf, int len)
+{
+       int offset = 0;
+
+       while (len) {
+               unsigned char c = *buf++;
+               int bytes, bad_offset;
+
+               len--;
+               offset++;
+
+               /* Simple US-ASCII? No worries. */
+               if (c < 0x80)
+                       continue;
+
+               bad_offset = offset-1;
+
                /*
-                * If p->item does not have anything common with other
-                * commits, there won't be any merge base.  If it is
-                * reachable from some of the others, p->item will be
-                * the merge base.  If its history is connected with
-                * others, but p->item is not reachable by others, we
-                * will get something other than p->item back.
+                * Count how many more high bits set: that's how
+                * many more bytes this sequence should have.
                 */
-               if (!base || (base->item != p->item))
-                       tail = &(commit_list_insert(p->item, tail)->next);
-               free_commit_list(base);
+               bytes = 0;
+               while (c & 0x40) {
+                       c <<= 1;
+                       bytes++;
+               }
+
+               /* Must be between 1 and 5 more bytes */
+               if (bytes < 1 || bytes > 5)
+                       return bad_offset;
+
+               /* Do we *have* that many bytes? */
+               if (len < bytes)
+                       return bad_offset;
+
+               offset += bytes;
+               len -= bytes;
+
+               /* And verify that they are good continuation bytes */
+               do {
+                       if ((*buf++ & 0xc0) != 0x80)
+                               return bad_offset;
+               } while (--bytes);
+
+               /* We could/should check the value and length here too */
+       }
+       return -1;
+}
+
+/*
+ * This verifies that the buffer is in proper utf8 format.
+ *
+ * If it isn't, it assumes any non-utf8 characters are Latin1,
+ * and does the conversion.
+ *
+ * Fixme: we should probably also disallow overlong forms and
+ * invalid characters. But we don't do that currently.
+ */
+static int verify_utf8(struct strbuf *buf)
+{
+       int ok = 1;
+       long pos = 0;
+
+       for (;;) {
+               int bad;
+               unsigned char c;
+               unsigned char replace[2];
+
+               bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
+               if (bad < 0)
+                       return ok;
+               pos += bad;
+               ok = 0;
+               c = buf->buf[pos];
+               strbuf_remove(buf, pos, 1);
+
+               /* We know 'c' must be in the range 128-255 */
+               replace[0] = 0xc0 + (c >> 6);
+               replace[1] = 0x80 + (c & 0x3f);
+               strbuf_insert(buf, pos, replace, 2);
+               pos += 2;
        }
-       free(other);
-       return result;
 }
 
 static const char commit_utf8_warn[] =
-"Warning: commit message does not conform to UTF-8.\n"
+"Warning: commit message did not conform to UTF-8.\n"
 "You may want to amend it after fixing the message, or set the config\n"
 "variable i18n.commitencoding to the encoding your project uses.\n";
 
-int commit_tree(const char *msg, unsigned char *tree,
-               struct commit_list *parents, unsigned char *ret,
-               const char *author)
+int commit_tree_extended(const struct strbuf *msg, unsigned char *tree,
+                        struct commit_list *parents, unsigned char *ret,
+                        const char *author, const char *sign_commit,
+                        struct commit_extra_header *extra)
 {
        int result;
        int encoding_is_utf8;
@@ -855,6 +1241,9 @@ int commit_tree(const char *msg, unsigned char *tree,
 
        assert_sha1_type(tree, OBJ_TREE);
 
+       if (memchr(msg->buf, '\0', msg->len))
+               return error("a NUL byte in commit log message not allowed.");
+
        /* Not having i18n.commitencoding is the same as having utf-8 */
        encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
 
@@ -868,29 +1257,85 @@ int commit_tree(const char *msg, unsigned char *tree,
         */
        while (parents) {
                struct commit_list *next = parents->next;
+               struct commit *parent = parents->item;
+
                strbuf_addf(&buffer, "parent %s\n",
-                       sha1_to_hex(parents->item->object.sha1));
+                           sha1_to_hex(parent->object.sha1));
                free(parents);
                parents = next;
        }
 
        /* Person/date information */
        if (!author)
-               author = git_author_info(IDENT_ERROR_ON_NO_NAME);
+               author = git_author_info(IDENT_STRICT);
        strbuf_addf(&buffer, "author %s\n", author);
-       strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_ERROR_ON_NO_NAME));
+       strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
        if (!encoding_is_utf8)
                strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
+
+       while (extra) {
+               add_extra_header(&buffer, extra);
+               extra = extra->next;
+       }
        strbuf_addch(&buffer, '\n');
 
        /* And add the comment */
-       strbuf_addstr(&buffer, msg);
+       strbuf_addbuf(&buffer, msg);
 
        /* And check the encoding */
-       if (encoding_is_utf8 && !is_utf8(buffer.buf))
+       if (encoding_is_utf8 && !verify_utf8(&buffer))
                fprintf(stderr, commit_utf8_warn);
 
+       if (sign_commit && do_sign_commit(&buffer, sign_commit))
+               return -1;
+
        result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
        strbuf_release(&buffer);
        return result;
 }
+
+struct commit *get_merge_parent(const char *name)
+{
+       struct object *obj;
+       struct commit *commit;
+       unsigned char sha1[20];
+       if (get_sha1(name, sha1))
+               return NULL;
+       obj = parse_object(sha1);
+       commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
+       if (commit && !commit->util) {
+               struct merge_remote_desc *desc;
+               desc = xmalloc(sizeof(*desc));
+               desc->obj = obj;
+               desc->name = strdup(name);
+               commit->util = desc;
+       }
+       return commit;
+}
+
+/*
+ * Append a commit to the end of the commit_list.
+ *
+ * next starts by pointing to the variable that holds the head of an
+ * empty commit_list, and is updated to point to the "next" field of
+ * the last item on the list as new commits are appended.
+ *
+ * Usage example:
+ *
+ *     struct commit_list *list;
+ *     struct commit_list **next = &list;
+ *
+ *     next = commit_list_append(c1, next);
+ *     next = commit_list_append(c2, next);
+ *     assert(commit_list_count(list) == 2);
+ *     return list;
+ */
+struct commit_list **commit_list_append(struct commit *commit,
+                                       struct commit_list **next)
+{
+       struct commit_list *new = xmalloc(sizeof(struct commit_list));
+       new->item = commit;
+       *next = new;
+       new->next = NULL;
+       return &new->next;
+}