rebase: Support preserving merges in non-interactive mode
[gitweb.git] / revision.c
index e75079a6e1316c74b4dff702170134dc7559898f..2f646deab09c423143185b7f7928ae46ab9f4c97 100644 (file)
@@ -489,7 +489,7 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
                        p->object.flags |= SEEN;
                        insert_by_date_cached(p, list, cached_base, cache_ptr);
                }
-               if(revs->first_parent_only)
+               if (revs->first_parent_only)
                        break;
        }
        return 0;
@@ -782,6 +782,10 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 
        revs->commit_format = CMIT_FMT_DEFAULT;
 
+       revs->grep_filter.status_only = 1;
+       revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
+       revs->grep_filter.regflags = REG_NEWLINE;
+
        diff_setup(&revs->diffopt);
        if (prefix && !revs->diffopt.prefix) {
                revs->diffopt.prefix = prefix;
@@ -946,33 +950,12 @@ void read_revisions_from_stdin(struct rev_info *revs)
 
 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 {
-       if (!revs->grep_filter) {
-               struct grep_opt *opt = xcalloc(1, sizeof(*opt));
-               opt->status_only = 1;
-               opt->pattern_tail = &(opt->pattern_list);
-               opt->regflags = REG_NEWLINE;
-               revs->grep_filter = opt;
-       }
-       append_grep_pattern(revs->grep_filter, ptn,
-                           "command line", 0, what);
+       append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
 }
 
-static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
+static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
 {
-       char *pat;
-       const char *prefix;
-       int patlen, fldlen;
-
-       fldlen = strlen(field);
-       patlen = strlen(pattern);
-       pat = xmalloc(patlen + fldlen + 10);
-       prefix = ".*";
-       if (*pattern == '^') {
-               prefix = "";
-               pattern++;
-       }
-       sprintf(pat, "^%s %s%s", field, prefix, pattern);
-       add_grep(revs, pat, GREP_PATTERN_HEAD);
+       append_header_grep_pattern(&revs->grep_filter, field, pattern);
 }
 
 static void add_message_grep(struct rev_info *revs, const char *pattern)
@@ -1045,6 +1028,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
        } else if (!strcmp(arg, "--topo-order")) {
                revs->lifo = 1;
                revs->topo_order = 1;
+       } else if (!strcmp(arg, "--simplify-merges")) {
+               revs->simplify_merges = 1;
+               revs->rewrite_parents = 1;
+               revs->simplify_history = 0;
+               revs->limited = 1;
        } else if (!strcmp(arg, "--date-order")) {
                revs->lifo = 0;
                revs->topo_order = 1;
@@ -1158,23 +1146,19 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
         * Grepping the commit log
         */
        else if (!prefixcmp(arg, "--author=")) {
-               add_header_grep(revs, "author", arg+9);
+               add_header_grep(revs, GREP_HEADER_AUTHOR, arg+9);
        } else if (!prefixcmp(arg, "--committer=")) {
-               add_header_grep(revs, "committer", arg+12);
+               add_header_grep(revs, GREP_HEADER_COMMITTER, arg+12);
        } else if (!prefixcmp(arg, "--grep=")) {
                add_message_grep(revs, arg+7);
        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
-               if (revs->grep_filter)
-                       revs->grep_filter->regflags |= REG_EXTENDED;
+               revs->grep_filter.regflags |= REG_EXTENDED;
        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
-               if (revs->grep_filter)
-                       revs->grep_filter->regflags |= REG_ICASE;
+               revs->grep_filter.regflags |= REG_ICASE;
        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
-               if (revs->grep_filter)
-                       revs->grep_filter->fixed = 1;
+               revs->grep_filter.fixed = 1;
        } else if (!strcmp(arg, "--all-match")) {
-               if (revs->grep_filter)
-                       revs->grep_filter->all_match = 1;
+               revs->grep_filter.all_match = 1;
        } else if (!prefixcmp(arg, "--encoding=")) {
                arg += 11;
                if (strcmp(arg, "none"))
@@ -1349,9 +1333,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
        if (diff_setup_done(&revs->diffopt) < 0)
                die("diff_setup_done failed");
 
-       if (revs->grep_filter) {
-               compile_grep_patterns(revs->grep_filter);
-       }
+       compile_grep_patterns(&revs->grep_filter);
 
        if (revs->reverse && revs->reflog_info)
                die("cannot combine --reverse with --walk-reflogs");
@@ -1378,6 +1360,179 @@ static void add_child(struct rev_info *revs, struct commit *parent, struct commi
        l->next = add_decoration(&revs->children, &parent->object, l);
 }
 
+static int remove_duplicate_parents(struct commit *commit)
+{
+       struct commit_list **pp, *p;
+       int surviving_parents;
+
+       /* Examine existing parents while marking ones we have seen... */
+       pp = &commit->parents;
+       while ((p = *pp) != NULL) {
+               struct commit *parent = p->item;
+               if (parent->object.flags & TMP_MARK) {
+                       *pp = p->next;
+                       continue;
+               }
+               parent->object.flags |= TMP_MARK;
+               pp = &p->next;
+       }
+       /* count them while clearing the temporary mark */
+       surviving_parents = 0;
+       for (p = commit->parents; p; p = p->next) {
+               p->item->object.flags &= ~TMP_MARK;
+               surviving_parents++;
+       }
+       return surviving_parents;
+}
+
+struct merge_simplify_state {
+       struct commit *simplified;
+};
+
+static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
+{
+       struct merge_simplify_state *st;
+
+       st = lookup_decoration(&revs->merge_simplification, &commit->object);
+       if (!st) {
+               st = xcalloc(1, sizeof(*st));
+               add_decoration(&revs->merge_simplification, &commit->object, st);
+       }
+       return st;
+}
+
+static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
+{
+       struct commit_list *p;
+       struct merge_simplify_state *st, *pst;
+       int cnt;
+
+       st = locate_simplify_state(revs, commit);
+
+       /*
+        * Have we handled this one?
+        */
+       if (st->simplified)
+               return tail;
+
+       /*
+        * An UNINTERESTING commit simplifies to itself, so does a
+        * root commit.  We do not rewrite parents of such commit
+        * anyway.
+        */
+       if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
+               st->simplified = commit;
+               return tail;
+       }
+
+       /*
+        * Do we know what commit all of our parents should be rewritten to?
+        * Otherwise we are not ready to rewrite this one yet.
+        */
+       for (cnt = 0, p = commit->parents; p; p = p->next) {
+               pst = locate_simplify_state(revs, p->item);
+               if (!pst->simplified) {
+                       tail = &commit_list_insert(p->item, tail)->next;
+                       cnt++;
+               }
+       }
+       if (cnt) {
+               tail = &commit_list_insert(commit, tail)->next;
+               return tail;
+       }
+
+       /*
+        * Rewrite our list of parents.
+        */
+       for (p = commit->parents; p; p = p->next) {
+               pst = locate_simplify_state(revs, p->item);
+               p->item = pst->simplified;
+       }
+       cnt = remove_duplicate_parents(commit);
+
+       /*
+        * It is possible that we are a merge and one side branch
+        * does not have any commit that touches the given paths;
+        * in such a case, the immediate parents will be rewritten
+        * to different commits.
+        *
+        *      o----X          X: the commit we are looking at;
+        *     /    /           o: a commit that touches the paths;
+        * ---o----'
+        *
+        * Further reduce the parents by removing redundant parents.
+        */
+       if (1 < cnt) {
+               struct commit_list *h = reduce_heads(commit->parents);
+               cnt = commit_list_count(h);
+               free_commit_list(commit->parents);
+               commit->parents = h;
+       }
+
+       /*
+        * A commit simplifies to itself if it is a root, if it is
+        * UNINTERESTING, if it touches the given paths, or if it is a
+        * merge and its parents simplifies to more than one commits
+        * (the first two cases are already handled at the beginning of
+        * this function).
+        *
+        * Otherwise, it simplifies to what its sole parent simplifies to.
+        */
+       if (!cnt ||
+           (commit->object.flags & UNINTERESTING) ||
+           !(commit->object.flags & TREESAME) ||
+           (1 < cnt))
+               st->simplified = commit;
+       else {
+               pst = locate_simplify_state(revs, commit->parents->item);
+               st->simplified = pst->simplified;
+       }
+       return tail;
+}
+
+static void simplify_merges(struct rev_info *revs)
+{
+       struct commit_list *list;
+       struct commit_list *yet_to_do, **tail;
+
+       if (!revs->topo_order)
+               sort_in_topological_order(&revs->commits, revs->lifo);
+       if (!revs->prune)
+               return;
+
+       /* feed the list reversed */
+       yet_to_do = NULL;
+       for (list = revs->commits; list; list = list->next)
+               commit_list_insert(list->item, &yet_to_do);
+       while (yet_to_do) {
+               list = yet_to_do;
+               yet_to_do = NULL;
+               tail = &yet_to_do;
+               while (list) {
+                       struct commit *commit = list->item;
+                       struct commit_list *next = list->next;
+                       free(list);
+                       list = next;
+                       tail = simplify_one(revs, commit, tail);
+               }
+       }
+
+       /* clean up the result, removing the simplified ones */
+       list = revs->commits;
+       revs->commits = NULL;
+       tail = &revs->commits;
+       while (list) {
+               struct commit *commit = list->item;
+               struct commit_list *next = list->next;
+               struct merge_simplify_state *st;
+               free(list);
+               list = next;
+               st = locate_simplify_state(revs, commit);
+               if (st->simplified == commit)
+                       tail = &commit_list_insert(commit, tail)->next;
+       }
+}
+
 static void set_children(struct rev_info *revs)
 {
        struct commit_list *l;
@@ -1418,6 +1573,8 @@ int prepare_revision_walk(struct rev_info *revs)
                        return -1;
        if (revs->topo_order)
                sort_in_topological_order(&revs->commits, revs->lifo);
+       if (revs->simplify_merges)
+               simplify_merges(revs);
        if (revs->children.name)
                set_children(revs);
        return 0;
@@ -1450,26 +1607,6 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp
        }
 }
 
-static void remove_duplicate_parents(struct commit *commit)
-{
-       struct commit_list **pp, *p;
-
-       /* Examine existing parents while marking ones we have seen... */
-       pp = &commit->parents;
-       while ((p = *pp) != NULL) {
-               struct commit *parent = p->item;
-               if (parent->object.flags & TMP_MARK) {
-                       *pp = p->next;
-                       continue;
-               }
-               parent->object.flags |= TMP_MARK;
-               pp = &p->next;
-       }
-       /* ... and clear the temporary mark */
-       for (p = commit->parents; p; p = p->next)
-               p->item->object.flags &= ~TMP_MARK;
-}
-
 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
 {
        struct commit_list **pp = &commit->parents;
@@ -1492,9 +1629,9 @@ static int rewrite_parents(struct rev_info *revs, struct commit *commit)
 
 static int commit_match(struct commit *commit, struct rev_info *opt)
 {
-       if (!opt->grep_filter)
+       if (!opt->grep_filter.pattern_list)
                return 1;
-       return grep_buffer(opt->grep_filter,
+       return grep_buffer(&opt->grep_filter,
                           NULL, /* we say nothing, not even filename */
                           commit->buffer, strlen(commit->buffer));
 }
@@ -1656,26 +1793,6 @@ static struct commit *get_revision_internal(struct rev_info *revs)
                return c;
        }
 
-       if (revs->reverse) {
-               int limit = -1;
-
-               if (0 <= revs->max_count) {
-                       limit = revs->max_count;
-                       if (0 < revs->skip_count)
-                               limit += revs->skip_count;
-               }
-               l = NULL;
-               while ((c = get_revision_1(revs))) {
-                       commit_list_insert(c, &l);
-                       if ((0 < limit) && !--limit)
-                               break;
-               }
-               revs->commits = l;
-               revs->reverse = 0;
-               revs->max_count = -1;
-               c = NULL;
-       }
-
        /*
         * Now pick up what they want to give us
         */
@@ -1748,7 +1865,23 @@ static struct commit *get_revision_internal(struct rev_info *revs)
 
 struct commit *get_revision(struct rev_info *revs)
 {
-       struct commit *c = get_revision_internal(revs);
+       struct commit *c;
+       struct commit_list *reversed;
+
+       if (revs->reverse) {
+               reversed = NULL;
+               while ((c = get_revision_internal(revs))) {
+                       commit_list_insert(c, &reversed);
+               }
+               revs->commits = reversed;
+               revs->reverse = 0;
+               revs->reverse_output_stage = 1;
+       }
+
+       if (revs->reverse_output_stage)
+               return pop_commit(&revs->commits);
+
+       c = get_revision_internal(revs);
        if (c && revs->graph)
                graph_update(revs->graph, c);
        return c;