Merge branch 'jc/autogc' into js/rebase-i
[gitweb.git] / revision.c
index f2ddd95e29e5eaef2cb4beb28c34921396d94fdf..33d092c3c4b4c08fb6f39228e464219df4cb4f1c 100644 (file)
@@ -7,6 +7,8 @@
 #include "refs.h"
 #include "revision.h"
 #include "grep.h"
+#include "reflog-walk.h"
+#include "patch-ids.h"
 
 static char *path_name(struct name_path *path, const char *name)
 {
@@ -61,8 +63,7 @@ void mark_tree_uninteresting(struct tree *tree)
        if (parse_tree(tree) < 0)
                die("bad tree %s", sha1_to_hex(obj->sha1));
 
-       desc.buf = tree->buffer;
-       desc.size = tree->size;
+       init_tree_desc(&desc, tree->buffer, tree->size);
        while (tree_entry(&desc, &entry)) {
                if (S_ISDIR(entry.mode))
                        mark_tree_uninteresting(lookup_tree(entry.sha1));
@@ -113,9 +114,20 @@ void mark_parents_uninteresting(struct commit *commit)
        }
 }
 
+static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
+{
+       if (revs->no_walk && (obj->flags & UNINTERESTING))
+               die("object ranges do not make sense when not walking revisions");
+       if (revs->reflog_info && obj->type == OBJ_COMMIT &&
+                       add_reflog_for_walk(revs->reflog_info,
+                               (struct commit *)obj, name))
+               return;
+       add_object_array_with_mode(obj, name, &revs->pending, mode);
+}
+
 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 {
-       add_object_array(obj, name, &revs->pending);
+       add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 }
 
 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
@@ -207,6 +219,13 @@ static int everybody_uninteresting(struct commit_list *orig)
        return 1;
 }
 
+/*
+ * The goal is to get REV_TREE_NEW as the result only if the
+ * diff consists of all '+' (and no other changes), and
+ * REV_TREE_DIFFERENT otherwise (of course if the trees are
+ * the same we want REV_TREE_SAME).  That means that once we
+ * get to REV_TREE_DIFFERENT, we do not have to look any further.
+ */
 static int tree_difference = REV_TREE_SAME;
 
 static void file_add_remove(struct diff_options *options,
@@ -230,6 +249,8 @@ static void file_add_remove(struct diff_options *options,
                diff = REV_TREE_NEW;
        }
        tree_difference = diff;
+       if (tree_difference == REV_TREE_DIFFERENT)
+               options->has_changes = 1;
 }
 
 static void file_change(struct diff_options *options,
@@ -239,43 +260,45 @@ static void file_change(struct diff_options *options,
                 const char *base, const char *path)
 {
        tree_difference = REV_TREE_DIFFERENT;
+       options->has_changes = 1;
 }
 
-int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
+static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 {
        if (!t1)
                return REV_TREE_NEW;
        if (!t2)
                return REV_TREE_DIFFERENT;
        tree_difference = REV_TREE_SAME;
+       revs->pruning.has_changes = 0;
        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
                           &revs->pruning) < 0)
                return REV_TREE_DIFFERENT;
        return tree_difference;
 }
 
-int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
+static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 {
        int retval;
        void *tree;
+       unsigned long size;
        struct tree_desc empty, real;
 
        if (!t1)
                return 0;
 
-       tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
+       tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
        if (!tree)
                return 0;
-       real.buf = tree;
-
-       empty.buf = "";
-       empty.size = 0;
+       init_tree_desc(&real, tree, size);
+       init_tree_desc(&empty, "", 0);
 
-       tree_difference = 0;
+       tree_difference = REV_TREE_SAME;
+       revs->pruning.has_changes = 0;
        retval = diff_tree(&empty, &real, "", &revs->pruning);
        free(tree);
 
-       return retval >= 0 && !tree_difference;
+       return retval >= 0 && (tree_difference == REV_TREE_SAME);
 }
 
 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
@@ -296,7 +319,10 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
        while ((parent = *pp) != NULL) {
                struct commit *p = parent->item;
 
-               parse_commit(p);
+               if (parse_commit(p) < 0)
+                       die("cannot simplify commit %s (because of %s)",
+                           sha1_to_hex(commit->object.sha1),
+                           sha1_to_hex(p->object.sha1));
                switch (rev_compare_tree(revs, p->tree, commit->tree)) {
                case REV_TREE_SAME:
                        tree_same = 1;
@@ -325,7 +351,10 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
                                 * IOW, we pretend this parent is a
                                 * "root" commit.
                                 */
-                               parse_commit(p);
+                               if (parse_commit(p) < 0)
+                                       die("cannot simplify commit %s (invalid %s)",
+                                           sha1_to_hex(commit->object.sha1),
+                                           sha1_to_hex(p->object.sha1));
                                p->parents = NULL;
                        }
                /* fallthrough */
@@ -340,13 +369,14 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
                commit->object.flags |= TREECHANGE;
 }
 
-static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
+static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 {
        struct commit_list *parent = commit->parents;
        unsigned left_flag;
+       int add, rest;
 
        if (commit->object.flags & ADDED)
-               return;
+               return 0;
        commit->object.flags |= ADDED;
 
        /*
@@ -365,7 +395,8 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
                while (parent) {
                        struct commit *p = parent->item;
                        parent = parent->next;
-                       parse_commit(p);
+                       if (parse_commit(p) < 0)
+                               return -1;
                        p->object.flags |= UNINTERESTING;
                        if (p->parents)
                                mark_parents_uninteresting(p);
@@ -374,7 +405,7 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
                        p->object.flags |= SEEN;
                        insert_by_date(p, list);
                }
-               return;
+               return 0;
        }
 
        /*
@@ -386,25 +417,113 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
                revs->prune_fn(revs, commit);
 
        if (revs->no_walk)
-               return;
+               return 0;
 
        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
-       parent = commit->parents;
-       while (parent) {
+
+       rest = !revs->first_parent_only;
+       for (parent = commit->parents, add = 1; parent; add = rest) {
                struct commit *p = parent->item;
 
                parent = parent->next;
-
-               parse_commit(p);
+               if (parse_commit(p) < 0)
+                       return -1;
                p->object.flags |= left_flag;
                if (p->object.flags & SEEN)
                        continue;
                p->object.flags |= SEEN;
-               insert_by_date(p, list);
+               if (add)
+                       insert_by_date(p, list);
+       }
+       return 0;
+}
+
+static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
+{
+       struct commit_list *p;
+       int left_count = 0, right_count = 0;
+       int left_first;
+       struct patch_ids ids;
+
+       /* First count the commits on the left and on the right */
+       for (p = list; p; p = p->next) {
+               struct commit *commit = p->item;
+               unsigned flags = commit->object.flags;
+               if (flags & BOUNDARY)
+                       ;
+               else if (flags & SYMMETRIC_LEFT)
+                       left_count++;
+               else
+                       right_count++;
+       }
+
+       left_first = left_count < right_count;
+       init_patch_ids(&ids);
+       if (revs->diffopt.nr_paths) {
+               ids.diffopts.nr_paths = revs->diffopt.nr_paths;
+               ids.diffopts.paths = revs->diffopt.paths;
+               ids.diffopts.pathlens = revs->diffopt.pathlens;
+       }
+
+       /* Compute patch-ids for one side */
+       for (p = list; p; p = p->next) {
+               struct commit *commit = p->item;
+               unsigned flags = commit->object.flags;
+
+               if (flags & BOUNDARY)
+                       continue;
+               /*
+                * If we have fewer left, left_first is set and we omit
+                * commits on the right branch in this loop.  If we have
+                * fewer right, we skip the left ones.
+                */
+               if (left_first != !!(flags & SYMMETRIC_LEFT))
+                       continue;
+               commit->util = add_commit_patch_id(commit, &ids);
+       }
+
+       /* Check the other side */
+       for (p = list; p; p = p->next) {
+               struct commit *commit = p->item;
+               struct patch_id *id;
+               unsigned flags = commit->object.flags;
+
+               if (flags & BOUNDARY)
+                       continue;
+               /*
+                * If we have fewer left, left_first is set and we omit
+                * commits on the left branch in this loop.
+                */
+               if (left_first == !!(flags & SYMMETRIC_LEFT))
+                       continue;
+
+               /*
+                * Have we seen the same patch id?
+                */
+               id = has_commit_patch_id(commit, &ids);
+               if (!id)
+                       continue;
+               id->seen = 1;
+               commit->object.flags |= SHOWN;
+       }
+
+       /* Now check the original side for seen ones */
+       for (p = list; p; p = p->next) {
+               struct commit *commit = p->item;
+               struct patch_id *ent;
+
+               ent = commit->util;
+               if (!ent)
+                       continue;
+               if (ent->seen)
+                       commit->object.flags |= SHOWN;
+               commit->util = NULL;
        }
+
+       free_patch_ids(&ids);
 }
 
-static void limit_list(struct rev_info *revs)
+static int limit_list(struct rev_info *revs)
 {
        struct commit_list *list = revs->commits;
        struct commit_list *newlist = NULL;
@@ -420,7 +539,8 @@ static void limit_list(struct rev_info *revs)
 
                if (revs->max_age != -1 && (commit->date < revs->max_age))
                        obj->flags |= UNINTERESTING;
-               add_parents_to_list(revs, commit, &list);
+               if (add_parents_to_list(revs, commit, &list) < 0)
+                       return -1;
                if (obj->flags & UNINTERESTING) {
                        mark_parents_uninteresting(commit);
                        if (everybody_uninteresting(list))
@@ -431,37 +551,11 @@ static void limit_list(struct rev_info *revs)
                        continue;
                p = &commit_list_insert(commit, p)->next;
        }
-       if (revs->boundary) {
-               /* mark the ones that are on the result list first */
-               for (list = newlist; list; list = list->next) {
-                       struct commit *commit = list->item;
-                       commit->object.flags |= TMP_MARK;
-               }
-               for (list = newlist; list; list = list->next) {
-                       struct commit *commit = list->item;
-                       struct object *obj = &commit->object;
-                       struct commit_list *parent;
-                       if (obj->flags & UNINTERESTING)
-                               continue;
-                       for (parent = commit->parents;
-                            parent;
-                            parent = parent->next) {
-                               struct commit *pcommit = parent->item;
-                               if (!(pcommit->object.flags & UNINTERESTING))
-                                       continue;
-                               pcommit->object.flags |= BOUNDARY;
-                               if (pcommit->object.flags & TMP_MARK)
-                                       continue;
-                               pcommit->object.flags |= TMP_MARK;
-                               p = &commit_list_insert(pcommit, p)->next;
-                       }
-               }
-               for (list = newlist; list; list = list->next) {
-                       struct commit *commit = list->item;
-                       commit->object.flags &= ~TMP_MARK;
-               }
-       }
+       if (revs->cherry_pick)
+               cherry_pick_list(newlist, revs);
+
        revs->commits = newlist;
+       return 0;
 }
 
 struct all_refs_cb {
@@ -476,7 +570,7 @@ static int handle_one_ref(const char *path, const unsigned char *sha1, int flag,
        struct all_refs_cb *cb = cb_data;
        struct object *object = get_reference(cb->all_revs, path, sha1,
                                              cb->all_flags);
-       add_pending_object(cb->all_revs, object, "");
+       add_pending_object(cb->all_revs, object, path);
        return 0;
 }
 
@@ -498,7 +592,7 @@ static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
                        add_pending_object(cb->all_revs, o, "");
                }
                else if (!cb->warned_bad_reflog) {
-                       warn("reflog of '%s' references pruned commits",
+                       warning("reflog of '%s' references pruned commits",
                                cb->name_for_errormsg);
                        cb->warned_bad_reflog = 1;
                }
@@ -528,7 +622,7 @@ static void handle_reflog(struct rev_info *revs, unsigned flags)
        struct all_refs_cb cb;
        cb.all_revs = revs;
        cb.all_flags = flags;
-       for_each_ref(handle_one_reflog, &cb);
+       for_each_reflog(handle_one_reflog, &cb);
 }
 
 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
@@ -569,6 +663,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
        revs->ignore_merges = 1;
        revs->simplify_history = 1;
        revs->pruning.recursive = 1;
+       revs->pruning.quiet = 1;
        revs->pruning.add_remove = file_add_remove;
        revs->pruning.change = file_change;
        revs->lifo = 1;
@@ -649,6 +744,7 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
                        int flags,
                        int cant_be_filename)
 {
+       unsigned mode;
        char *dotdot;
        struct object *object;
        unsigned char sha1[20];
@@ -722,12 +818,12 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
                local_flags = UNINTERESTING;
                arg++;
        }
-       if (get_sha1(arg, sha1))
+       if (get_sha1_with_mode(arg, sha1, &mode))
                return -1;
        if (!cant_be_filename)
                verify_non_filename(revs->prefix, arg);
        object = get_reference(revs, arg, sha1, flags ^ local_flags);
-       add_pending_object(revs, object, arg);
+       add_pending_object_with_mode(revs, object, arg, mode);
        return 0;
 }
 
@@ -790,6 +886,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
        const char **unrecognized = argv + 1;
        int left = 1;
        int all_match = 0;
+       int regflags = 0;
 
        /* First, search for "--" */
        seen_dashdash = 0;
@@ -799,7 +896,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                        continue;
                argv[i] = NULL;
                argc = i;
-               revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
+               if (argv[i + 1])
+                       revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
                seen_dashdash = 1;
                break;
        }
@@ -809,11 +907,11 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                const char *arg = argv[i];
                if (*arg == '-') {
                        int opts;
-                       if (!strncmp(arg, "--max-count=", 12)) {
+                       if (!prefixcmp(arg, "--max-count=")) {
                                revs->max_count = atoi(arg + 12);
                                continue;
                        }
-                       if (!strncmp(arg, "--skip=", 7)) {
+                       if (!prefixcmp(arg, "--skip=")) {
                                revs->skip_count = atoi(arg + 7);
                                continue;
                        }
@@ -828,31 +926,31 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->max_count = atoi(argv[++i]);
                                continue;
                        }
-                       if (!strncmp(arg,"-n",2)) {
+                       if (!prefixcmp(arg, "-n")) {
                                revs->max_count = atoi(arg + 2);
                                continue;
                        }
-                       if (!strncmp(arg, "--max-age=", 10)) {
+                       if (!prefixcmp(arg, "--max-age=")) {
                                revs->max_age = atoi(arg + 10);
                                continue;
                        }
-                       if (!strncmp(arg, "--since=", 8)) {
+                       if (!prefixcmp(arg, "--since=")) {
                                revs->max_age = approxidate(arg + 8);
                                continue;
                        }
-                       if (!strncmp(arg, "--after=", 8)) {
+                       if (!prefixcmp(arg, "--after=")) {
                                revs->max_age = approxidate(arg + 8);
                                continue;
                        }
-                       if (!strncmp(arg, "--min-age=", 10)) {
+                       if (!prefixcmp(arg, "--min-age=")) {
                                revs->min_age = atoi(arg + 10);
                                continue;
                        }
-                       if (!strncmp(arg, "--before=", 9)) {
+                       if (!prefixcmp(arg, "--before=")) {
                                revs->min_age = approxidate(arg + 9);
                                continue;
                        }
-                       if (!strncmp(arg, "--until=", 8)) {
+                       if (!prefixcmp(arg, "--until=")) {
                                revs->min_age = approxidate(arg + 8);
                                continue;
                        }
@@ -860,10 +958,19 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                handle_all(revs, flags);
                                continue;
                        }
+                       if (!strcmp(arg, "--first-parent")) {
+                               revs->first_parent_only = 1;
+                               continue;
+                       }
                        if (!strcmp(arg, "--reflog")) {
                                handle_reflog(revs, flags);
                                continue;
                        }
+                       if (!strcmp(arg, "-g") ||
+                                       !strcmp(arg, "--walk-reflogs")) {
+                               init_reflog_walk(&revs->reflog_info);
+                               continue;
+                       }
                        if (!strcmp(arg, "--not")) {
                                flags ^= UNINTERESTING;
                                continue;
@@ -915,6 +1022,11 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->left_right = 1;
                                continue;
                        }
+                       if (!strcmp(arg, "--cherry-pick")) {
+                               revs->cherry_pick = 1;
+                               revs->limited = 1;
+                               continue;
+                       }
                        if (!strcmp(arg, "--objects")) {
                                revs->tag_objects = 1;
                                revs->tree_objects = 1;
@@ -935,7 +1047,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->num_ignore_packed = 0;
                                continue;
                        }
-                       if (!strncmp(arg, "--unpacked=", 11)) {
+                       if (!prefixcmp(arg, "--unpacked=")) {
                                revs->unpacked = 1;
                                add_ignore_packed(revs, arg+11);
                                continue;
@@ -971,7 +1083,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->verbose_header = 1;
                                continue;
                        }
-                       if (!strncmp(arg, "--pretty", 8)) {
+                       if (!prefixcmp(arg, "--pretty")) {
                                revs->verbose_header = 1;
                                revs->commit_format = get_commit_format(arg+8);
                                continue;
@@ -996,7 +1108,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->abbrev = DEFAULT_ABBREV;
                                continue;
                        }
-                       if (!strncmp(arg, "--abbrev=", 9)) {
+                       if (!prefixcmp(arg, "--abbrev=")) {
                                revs->abbrev = strtoul(arg + 9, NULL, 10);
                                if (revs->abbrev < MINIMUM_ABBREV)
                                        revs->abbrev = MINIMUM_ABBREV;
@@ -1018,41 +1130,87 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                continue;
                        }
                        if (!strcmp(arg, "--relative-date")) {
-                               revs->relative_date = 1;
+                               revs->date_mode = DATE_RELATIVE;
+                               continue;
+                       }
+                       if (!strncmp(arg, "--date=", 7)) {
+                               if (!strcmp(arg + 7, "relative"))
+                                       revs->date_mode = DATE_RELATIVE;
+                               else if (!strcmp(arg + 7, "iso8601") ||
+                                        !strcmp(arg + 7, "iso"))
+                                       revs->date_mode = DATE_ISO8601;
+                               else if (!strcmp(arg + 7, "rfc2822") ||
+                                        !strcmp(arg + 7, "rfc"))
+                                       revs->date_mode = DATE_RFC2822;
+                               else if (!strcmp(arg + 7, "short"))
+                                       revs->date_mode = DATE_SHORT;
+                               else if (!strcmp(arg + 7, "local"))
+                                       revs->date_mode = DATE_LOCAL;
+                               else if (!strcmp(arg + 7, "default"))
+                                       revs->date_mode = DATE_NORMAL;
+                               else
+                                       die("unknown date format %s", arg);
+                               continue;
+                       }
+                       if (!strcmp(arg, "--log-size")) {
+                               revs->show_log_size = 1;
                                continue;
                        }
 
                        /*
                         * Grepping the commit log
                         */
-                       if (!strncmp(arg, "--author=", 9)) {
+                       if (!prefixcmp(arg, "--author=")) {
                                add_header_grep(revs, "author", arg+9);
                                continue;
                        }
-                       if (!strncmp(arg, "--committer=", 12)) {
+                       if (!prefixcmp(arg, "--committer=")) {
                                add_header_grep(revs, "committer", arg+12);
                                continue;
                        }
-                       if (!strncmp(arg, "--grep=", 7)) {
+                       if (!prefixcmp(arg, "--grep=")) {
                                add_message_grep(revs, arg+7);
                                continue;
                        }
+                       if (!strcmp(arg, "--extended-regexp") ||
+                           !strcmp(arg, "-E")) {
+                               regflags |= REG_EXTENDED;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--regexp-ignore-case") ||
+                           !strcmp(arg, "-i")) {
+                               regflags |= REG_ICASE;
+                               continue;
+                       }
                        if (!strcmp(arg, "--all-match")) {
                                all_match = 1;
                                continue;
                        }
-                       if (!strncmp(arg, "--encoding=", 11)) {
+                       if (!prefixcmp(arg, "--encoding=")) {
                                arg += 11;
                                if (strcmp(arg, "none"))
-                                       git_log_output_encoding = strdup(arg);
+                                       git_log_output_encoding = xstrdup(arg);
                                else
                                        git_log_output_encoding = "";
                                continue;
                        }
+                       if (!strcmp(arg, "--reverse")) {
+                               revs->reverse ^= 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--no-walk")) {
+                               revs->no_walk = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--do-walk")) {
+                               revs->no_walk = 0;
+                               continue;
+                       }
 
                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
                        if (opts > 0) {
-                               revs->diff = 1;
+                               if (strcmp(argv[i], "-z"))
+                                       revs->diff = 1;
                                i += opts - 1;
                                continue;
                        }
@@ -1081,15 +1239,19 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                }
        }
 
+       if (revs->grep_filter)
+               revs->grep_filter->regflags |= regflags;
+
        if (show_merge)
                prepare_show_merge(revs);
        if (def && !revs->pending.nr) {
                unsigned char sha1[20];
                struct object *object;
-               if (get_sha1(def, sha1))
+               unsigned mode;
+               if (get_sha1_with_mode(def, sha1, &mode))
                        die("bad default revision '%s'", def);
                object = get_reference(revs, def, sha1, 0);
-               add_pending_object(revs, object, def);
+               add_pending_object_with_mode(revs, object, def, mode);
        }
 
        if (revs->topo_order)
@@ -1097,7 +1259,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 
        if (revs->prune_data) {
                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
-               revs->prune_fn = try_to_simplify_commit;
+               /* Can't prune commits with rename following: the paths change.. */
+               if (!revs->diffopt.follow_renames)
+                       revs->prune_fn = try_to_simplify_commit;
                if (!revs->full_diff)
                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
        }
@@ -1115,10 +1279,13 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                compile_grep_patterns(revs->grep_filter);
        }
 
+       if (revs->reverse && revs->reflog_info)
+               die("cannot combine --reverse with --walk-reflogs");
+
        return left;
 }
 
-void prepare_revision_walk(struct rev_info *revs)
+int prepare_revision_walk(struct rev_info *revs)
 {
        int nr = revs->pending.nr;
        struct object_array_entry *e, *list;
@@ -1140,53 +1307,78 @@ void prepare_revision_walk(struct rev_info *revs)
        free(list);
 
        if (revs->no_walk)
-               return;
+               return 0;
        if (revs->limited)
-               limit_list(revs);
+               if (limit_list(revs) < 0)
+                       return -1;
        if (revs->topo_order)
                sort_in_topological_order_fn(&revs->commits, revs->lifo,
                                             revs->topo_setter,
                                             revs->topo_getter);
+       return 0;
 }
 
-static int rewrite_one(struct rev_info *revs, struct commit **pp)
+enum rewrite_result {
+       rewrite_one_ok,
+       rewrite_one_noparents,
+       rewrite_one_error,
+};
+
+static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
 {
        for (;;) {
                struct commit *p = *pp;
                if (!revs->limited)
-                       add_parents_to_list(revs, p, &revs->commits);
+                       if (add_parents_to_list(revs, p, &revs->commits) < 0)
+                               return rewrite_one_error;
                if (p->parents && p->parents->next)
-                       return 0;
+                       return rewrite_one_ok;
                if (p->object.flags & (TREECHANGE | UNINTERESTING))
-                       return 0;
+                       return rewrite_one_ok;
                if (!p->parents)
-                       return -1;
+                       return rewrite_one_noparents;
                *pp = p->parents->item;
        }
 }
 
-static void rewrite_parents(struct rev_info *revs, struct commit *commit)
+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;
        while (*pp) {
                struct commit_list *parent = *pp;
-               if (rewrite_one(revs, &parent->item) < 0) {
+               switch (rewrite_one(revs, &parent->item)) {
+               case rewrite_one_ok:
+                       break;
+               case rewrite_one_noparents:
                        *pp = parent->next;
                        continue;
+               case rewrite_one_error:
+                       return -1;
                }
                pp = &parent->next;
        }
-}
-
-static void mark_boundary_to_show(struct commit *commit)
-{
-       struct commit_list *p = commit->parents;
-       while (p) {
-               commit = p->item;
-               p = p->next;
-               if (commit->object.flags & BOUNDARY)
-                       commit->object.flags |= BOUNDARY_SHOW;
-       }
+       remove_duplicate_parents(commit);
+       return 0;
 }
 
 static int commit_match(struct commit *commit, struct rev_info *opt)
@@ -1210,6 +1402,9 @@ static struct commit *get_revision_1(struct rev_info *revs)
                revs->commits = entry->next;
                free(entry);
 
+               if (revs->reflog_info)
+                       fake_reflog_parent(revs->reflog_info, commit);
+
                /*
                 * If we haven't done the list limiting, we need to look at
                 * the parents here. We also need to do the date-based limiting
@@ -1219,7 +1414,8 @@ static struct commit *get_revision_1(struct rev_info *revs)
                        if (revs->max_age != -1 &&
                            (commit->date < revs->max_age))
                                continue;
-                       add_parents_to_list(revs, commit, &revs->commits);
+                       if (add_parents_to_list(revs, commit, &revs->commits) < 0)
+                               return NULL;
                }
                if (commit->object.flags & SHOWN)
                        continue;
@@ -1228,18 +1424,6 @@ static struct commit *get_revision_1(struct rev_info *revs)
                                                    revs->ignore_packed))
                    continue;
 
-               /* We want to show boundary commits only when their
-                * children are shown.  When path-limiter is in effect,
-                * rewrite_parents() drops some commits from getting shown,
-                * and there is no point showing boundary parents that
-                * are not shown.  After rewrite_parents() rewrites the
-                * parents of a commit that is shown, we mark the boundary
-                * parents with BOUNDARY_SHOW.
-                */
-               if (commit->object.flags & BOUNDARY_SHOW) {
-                       commit->object.flags |= SHOWN;
-                       return commit;
-               }
                if (commit->object.flags & UNINTERESTING)
                        continue;
                if (revs->min_age != -1 && (commit->date > revs->min_age))
@@ -1259,38 +1443,139 @@ static struct commit *get_revision_1(struct rev_info *revs)
                                if (!commit->parents || !commit->parents->next)
                                        continue;
                        }
-                       if (revs->parents)
-                               rewrite_parents(revs, commit);
+                       if (revs->parents && rewrite_parents(revs, commit) < 0)
+                               return NULL;
                }
-               if (revs->boundary)
-                       mark_boundary_to_show(commit);
-               commit->object.flags |= SHOWN;
                return commit;
        } while (revs->commits);
        return NULL;
 }
 
+static void gc_boundary(struct object_array *array)
+{
+       unsigned nr = array->nr;
+       unsigned alloc = array->alloc;
+       struct object_array_entry *objects = array->objects;
+
+       if (alloc <= nr) {
+               unsigned i, j;
+               for (i = j = 0; i < nr; i++) {
+                       if (objects[i].item->flags & SHOWN)
+                               continue;
+                       if (i != j)
+                               objects[j] = objects[i];
+                       j++;
+               }
+               for (i = j; i < nr; i++)
+                       objects[i].item = NULL;
+               array->nr = j;
+       }
+}
+
 struct commit *get_revision(struct rev_info *revs)
 {
        struct commit *c = NULL;
+       struct commit_list *l;
+
+       if (revs->boundary == 2) {
+               unsigned i;
+               struct object_array *array = &revs->boundary_commits;
+               struct object_array_entry *objects = array->objects;
+               for (i = 0; i < array->nr; i++) {
+                       c = (struct commit *)(objects[i].item);
+                       if (!c)
+                               continue;
+                       if (!(c->object.flags & CHILD_SHOWN))
+                               continue;
+                       if (!(c->object.flags & SHOWN))
+                               break;
+               }
+               if (array->nr <= i)
+                       return NULL;
 
-       if (0 < revs->skip_count) {
-               while ((c = get_revision_1(revs)) != NULL) {
-                       if (revs->skip_count-- <= 0)
+               c->object.flags |= SHOWN | BOUNDARY;
+               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
+        */
+       c = get_revision_1(revs);
+       if (c) {
+               while (0 < revs->skip_count) {
+                       revs->skip_count--;
+                       c = get_revision_1(revs);
+                       if (!c)
                                break;
                }
        }
 
-       /* Check the max_count ... */
+       /*
+        * Check the max_count.
+        */
        switch (revs->max_count) {
        case -1:
                break;
        case 0:
-               return NULL;
+               c = NULL;
+               break;
        default:
                revs->max_count--;
        }
+
        if (c)
+               c->object.flags |= SHOWN;
+
+       if (!revs->boundary) {
                return c;
-       return get_revision_1(revs);
+       }
+
+       if (!c) {
+               /*
+                * get_revision_1() runs out the commits, and
+                * we are done computing the boundaries.
+                * switch to boundary commits output mode.
+                */
+               revs->boundary = 2;
+               return get_revision(revs);
+       }
+
+       /*
+        * boundary commits are the commits that are parents of the
+        * ones we got from get_revision_1() but they themselves are
+        * not returned from get_revision_1().  Before returning
+        * 'c', we need to mark its parents that they could be boundaries.
+        */
+
+       for (l = c->parents; l; l = l->next) {
+               struct object *p;
+               p = &(l->item->object);
+               if (p->flags & (CHILD_SHOWN | SHOWN))
+                       continue;
+               p->flags |= CHILD_SHOWN;
+               gc_boundary(&revs->boundary_commits);
+               add_object_array(p, NULL, &revs->boundary_commits);
+       }
+
+       return c;
 }