Merge branch 'js/merge-base' into next

* js/merge-base:
  commit.c: do not redefine UNINTERESTING bit.
  Fold get_merge_bases_clean() into get_merge_bases()
  Make clear_commit_marks() clean harder
  Add '...' operator for revisions
  Add get_merge_bases_clean()

Documentation/git-rev-list.txt

@@ -15,6 +15,7 @@ SYNOPSIS
 	     [ \--sparse ]
 	     [ \--no-merges ]
 	     [ \--remove-empty ]
+	     [ \--not ]
 	     [ \--all ]
 	     [ \--topo-order ]
 	     [ \--parents ]
@@ -37,6 +38,14 @@ not in 'baz'".
 A special notation <commit1>..<commit2> can be used as a
 short-hand for {caret}<commit1> <commit2>.
 
+Another special notation is <commit1>...<commit2> which is useful for
+merges.  The resulting set of commits is the symmetric difference
+between the two operands.  The following two commands are equivalent:
+
+------------
+$ git-rev-list A B --not $(git-merge-base --all A B)
+$ git-rev-list A...B
+------------
 
 OPTIONS
 -------
@@ -93,6 +102,11 @@ OPTIONS
 --remove-empty::
 	Stop when a given path disappears from the tree.
 
+--not::
+	Reverses the meaning of the '{caret}' prefix (or lack
+	thereof) for all following revision specifiers, up to
+	the next `--not`.
+
 --all::
 	Pretend as if all the refs in `$GIT_DIR/refs/` are
 	listed on the command line as <commit>.

commit.c

@@ -397,13 +397,12 @@ void clear_commit_marks(struct commit *commit, unsigned int mark)
 {
 	struct commit_list *parents;
 
+	if (!commit)
+		return;
 	parents = commit->parents;
 	commit->object.flags &= ~mark;
 	while (parents) {
-		struct commit *parent = parents->item;
-		if (parent && parent->object.parsed &&
-		    (parent->object.flags & mark))
-			clear_commit_marks(parent, mark);
+		clear_commit_marks(parents->item, mark);
 		parents = parents->next;
 	}
 }
@@ -849,16 +848,17 @@ void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 
 /* merge-rebase stuff */
 
-#define PARENT1 1
-#define PARENT2 2
-#define UNINTERESTING 4
+/* bits #0..7 in revision.h */
+#define PARENT1		(1u<< 8)
+#define PARENT2		(1u<< 9)
+#define STALE		(1u<<10)
 
 static struct commit *interesting(struct commit_list *list)
 {
 	while (list) {
 		struct commit *commit = list->item;
 		list = list->next;
-		if (commit->object.flags & UNINTERESTING)
+		if (commit->object.flags & STALE)
 			continue;
 		return commit;
 	}
@@ -920,17 +920,17 @@ static struct commit *interesting(struct commit_list *list)
  *
  * Next, we pop B and something very interesting happens.  It has flags==3
  * so it is also placed on the result list, and its parents are marked
- * uninteresting, retroactively, and placed back on the list:
+ * stale, retroactively, and placed back on the list:
  *
  *    list=C(7), result=C(7) B(3)
  *
  * Now, list does not have any interesting commit.  So we find the newest
- * commit from the result list that is not marked uninteresting.  Which is
+ * commit from the result list that is not marked stale.  Which is
  * commit B.
  *
  *
  * Another pathological example how this thing used to fail to mark an
- * ancestor of a merge base as UNINTERESTING before we introduced the
+ * ancestor of a merge base as STALE before we introduced the
  * postprocessing phase (mark_reachable_commits).
  *
  *		  2
@@ -960,8 +960,8 @@ static struct commit *interesting(struct commit_list *list)
  *	 C7			2 3 7 1 3 2 1 2
  *
  * At this point, unfortunately, everybody in the list is
- * uninteresting, so we fail to complete the following two
- * steps to fully marking uninteresting commits.
+ * stale, so we fail to complete the following two
+ * steps to fully marking stale commits.
  *
  *	 D7			2 3 7 7 3 2 1 2
  *	 E7			2 3 7 7 7 2 1 2
@@ -981,10 +981,10 @@ static void mark_reachable_commits(struct commit_list *result,
 	 */
 	for (tmp = result; tmp; tmp = tmp->next) {
 		struct commit *c = tmp->item;
-		/* Reinject uninteresting ones to list,
+		/* Reinject stale ones to list,
 		 * so we can scan their parents.
 		 */
-		if (c->object.flags & UNINTERESTING)
+		if (c->object.flags & STALE)
 			commit_list_insert(c, &list);
 	}
 	while (list) {
@@ -995,8 +995,8 @@ static void mark_reachable_commits(struct commit_list *result,
 		list = list->next;
 		free(tmp);
 
-		/* Anything taken out of the list is uninteresting, so
-		 * mark all its parents uninteresting.  We do not
+		/* Anything taken out of the list is stale, so
+		 * mark all its parents stale.  We do not
 		 * parse new ones (we already parsed all the relevant
 		 * ones).
 		 */
@@ -1004,15 +1004,16 @@ static void mark_reachable_commits(struct commit_list *result,
 		while (parents) {
 			struct commit *p = parents->item;
 			parents = parents->next;
-			if (!(p->object.flags & UNINTERESTING)) {
-				p->object.flags |= UNINTERESTING;
+			if (!(p->object.flags & STALE)) {
+				p->object.flags |= STALE;
 				commit_list_insert(p, &list);
 			}
 		}
 	}
 }
 
-struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2)
+struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2,
+                                    int cleanup)
 {
 	struct commit_list *list = NULL;
 	struct commit_list *result = NULL;
@@ -1033,7 +1034,7 @@ struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2)
 		struct commit *commit = list->item;
 		struct commit_list *parents;
 		int flags = commit->object.flags
-			& (PARENT1 | PARENT2 | UNINTERESTING);
+			& (PARENT1 | PARENT2 | STALE);
 
 		tmp = list;
 		list = list->next;
@@ -1041,8 +1042,8 @@ struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2)
 		if (flags == (PARENT1 | PARENT2)) {
 			insert_by_date(commit, &result);
 
-			/* Mark parents of a found merge uninteresting */
-			flags |= UNINTERESTING;
+			/* Mark parents of a found merge stale */
+			flags |= STALE;
 		}
 		parents = commit->parents;
 		while (parents) {
@@ -1066,7 +1067,7 @@ struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2)
 	for (tmp = result, list = NULL; tmp; ) {
 		struct commit *commit = tmp->item;
 		struct commit_list *next = tmp->next;
-		if (commit->object.flags & UNINTERESTING) {
+		if (commit->object.flags & STALE) {
 			if (list != NULL)
 				list->next = next;
 			free(tmp);
@@ -1074,15 +1075,16 @@ struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2)
 			if (list == NULL)
 				result = tmp;
 			list = tmp;
-			commit->object.flags |= UNINTERESTING;
+			commit->object.flags |= STALE;
 		}
 
 		tmp = next;
 	}
 
-	/* reset flags */
-	clear_commit_marks(rev1, PARENT1 | PARENT2 | UNINTERESTING);
-	clear_commit_marks(rev2, PARENT1 | PARENT2 | UNINTERESTING);
+	if (cleanup) {
+		clear_commit_marks(rev1, PARENT1 | PARENT2 | STALE);
+		clear_commit_marks(rev2, PARENT1 | PARENT2 | STALE);
+	}
 
 	return result;
 }

commit.h

@@ -105,6 +105,6 @@ struct commit_graft *read_graft_line(char *buf, int len);
 int register_commit_graft(struct commit_graft *, int);
 int read_graft_file(const char *graft_file);
 
-extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2);
+extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup);
 
 #endif /* COMMIT_H */

merge-base.c

@@ -6,7 +6,7 @@ static int show_all = 0;
 
 static int merge_base(struct commit *rev1, struct commit *rev2)
 {
-	struct commit_list *result = get_merge_bases(rev1, rev2);
+	struct commit_list *result = get_merge_bases(rev1, rev2, 0);
 
 	if (!result)
 		return 1;

revision.c

@@ -537,6 +537,18 @@ void init_revisions(struct rev_info *revs)
 	diff_setup(&revs->diffopt);
 }
 
+static void add_pending_commit_list(struct rev_info *revs,
+                                    struct commit_list *commit_list,
+                                    unsigned int flags)
+{
+	while (commit_list) {
+		struct object *object = &commit_list->item->object;
+		object->flags |= flags;
+		add_pending_object(revs, object, sha1_to_hex(object->sha1));
+		commit_list = commit_list->next;
+	}
+}
+
 /*
  * Parse revision information, filling in the "rev_info" structure,
  * and removing the used arguments from the argument list.
@@ -772,27 +784,45 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 			unsigned char from_sha1[20];
 			const char *next = dotdot + 2;
 			const char *this = arg;
+			int symmetric = *next == '.';
+			unsigned int flags_exclude = flags ^ UNINTERESTING;
+
 			*dotdot = 0;
+			next += symmetric;
+
 			if (!*next)
 				next = "HEAD";
 			if (dotdot == arg)
 				this = "HEAD";
 			if (!get_sha1(this, from_sha1) &&
 			    !get_sha1(next, sha1)) {
-				struct object *exclude;
-				struct object *include;
+				struct commit *a, *b;
+				struct commit_list *exclude;
 
-				exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
-				include = get_reference(revs, next, sha1, flags);
-				if (!exclude || !include)
-					die("Invalid revision range %s..%s", arg, next);
+				a = lookup_commit_reference(from_sha1);
+				b = lookup_commit_reference(sha1);
+				if (!a || !b) {
+					die(symmetric ?
+					    "Invalid symmetric difference expression %s...%s" :
+					    "Invalid revision range %s..%s",
+					    arg, next);
+				}
 
 				if (!seen_dashdash) {
 					*dotdot = '.';
 					verify_non_filename(revs->prefix, arg);
 				}
-				add_pending_object(revs, exclude, this);
-				add_pending_object(revs, include, next);
+
+				if (symmetric) {
+					exclude = get_merge_bases(a, b, 1);
+					add_pending_commit_list(revs, exclude,
+					                        flags_exclude);
+					a->object.flags |= flags;
+				} else
+					a->object.flags |= flags_exclude;
+				b->object.flags |= flags;
+				add_pending_object(revs, &a->object, this);
+				add_pending_object(revs, &b->object, next);
 				continue;
 			}
 			*dotdot = '.';