git-commit --amend: allow empty commit.
[gitweb.git] / revision.c
index 67ff4de2d1e70e061aebc834e7b9632c8d7bf6cb..a3df8100763136e8936b8e3b4c647d5b83cc7239 100644 (file)
@@ -3,6 +3,7 @@
 #include "blob.h"
 #include "tree.h"
 #include "commit.h"
+#include "diff.h"
 #include "refs.h"
 #include "revision.h"
 
@@ -183,6 +184,232 @@ static struct commit *get_commit_reference(struct rev_info *revs, const char *na
        die("%s is unknown object", name);
 }
 
+static int everybody_uninteresting(struct commit_list *orig)
+{
+       struct commit_list *list = orig;
+       while (list) {
+               struct commit *commit = list->item;
+               list = list->next;
+               if (commit->object.flags & UNINTERESTING)
+                       continue;
+               return 0;
+       }
+       return 1;
+}
+
+#define TREE_SAME      0
+#define TREE_NEW       1
+#define TREE_DIFFERENT 2
+static int tree_difference = TREE_SAME;
+
+static void file_add_remove(struct diff_options *options,
+                   int addremove, unsigned mode,
+                   const unsigned char *sha1,
+                   const char *base, const char *path)
+{
+       int diff = TREE_DIFFERENT;
+
+       /*
+        * Is it an add of a new file? It means that
+        * the old tree didn't have it at all, so we
+        * will turn "TREE_SAME" -> "TREE_NEW", but
+        * leave any "TREE_DIFFERENT" alone (and if
+        * it already was "TREE_NEW", we'll keep it
+        * "TREE_NEW" of course).
+        */
+       if (addremove == '+') {
+               diff = tree_difference;
+               if (diff != TREE_SAME)
+                       return;
+               diff = TREE_NEW;
+       }
+       tree_difference = diff;
+}
+
+static void file_change(struct diff_options *options,
+                unsigned old_mode, unsigned new_mode,
+                const unsigned char *old_sha1,
+                const unsigned char *new_sha1,
+                const char *base, const char *path)
+{
+       tree_difference = TREE_DIFFERENT;
+}
+
+static struct diff_options diff_opt = {
+       .recursive = 1,
+       .add_remove = file_add_remove,
+       .change = file_change,
+};
+
+static int compare_tree(struct tree *t1, struct tree *t2)
+{
+       if (!t1)
+               return TREE_NEW;
+       if (!t2)
+               return TREE_DIFFERENT;
+       tree_difference = TREE_SAME;
+       if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
+               return TREE_DIFFERENT;
+       return tree_difference;
+}
+
+static int same_tree_as_empty(struct tree *t1)
+{
+       int retval;
+       void *tree;
+       struct tree_desc empty, real;
+
+       if (!t1)
+               return 0;
+
+       tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
+       if (!tree)
+               return 0;
+       real.buf = tree;
+
+       empty.buf = "";
+       empty.size = 0;
+
+       tree_difference = 0;
+       retval = diff_tree(&empty, &real, "", &diff_opt);
+       free(tree);
+
+       return retval >= 0 && !tree_difference;
+}
+
+static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
+{
+       struct commit_list **pp, *parent;
+
+       if (!commit->tree)
+               return;
+
+       if (!commit->parents) {
+               if (!same_tree_as_empty(commit->tree))
+                       commit->object.flags |= TREECHANGE;
+               return;
+       }
+
+       pp = &commit->parents;
+       while ((parent = *pp) != NULL) {
+               struct commit *p = parent->item;
+
+               if (p->object.flags & UNINTERESTING) {
+                       pp = &parent->next;
+                       continue;
+               }
+
+               parse_commit(p);
+               switch (compare_tree(p->tree, commit->tree)) {
+               case TREE_SAME:
+                       parent->next = NULL;
+                       commit->parents = parent;
+                       return;
+
+               case TREE_NEW:
+                       if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
+                               *pp = parent->next;
+                               continue;
+                       }
+               /* fallthrough */
+               case TREE_DIFFERENT:
+                       pp = &parent->next;
+                       continue;
+               }
+               die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
+       }
+       commit->object.flags |= TREECHANGE;
+}
+
+static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
+{
+       struct commit_list *parent = commit->parents;
+
+       /*
+        * If the commit is uninteresting, don't try to
+        * prune parents - we want the maximal uninteresting
+        * set.
+        *
+        * Normally we haven't parsed the parent
+        * yet, so we won't have a parent of a parent
+        * here. However, it may turn out that we've
+        * reached this commit some other way (where it
+        * wasn't uninteresting), in which case we need
+        * to mark its parents recursively too..
+        */
+       if (commit->object.flags & UNINTERESTING) {
+               while (parent) {
+                       struct commit *p = parent->item;
+                       parent = parent->next;
+                       parse_commit(p);
+                       p->object.flags |= UNINTERESTING;
+                       if (p->parents)
+                               mark_parents_uninteresting(p);
+                       if (p->object.flags & SEEN)
+                               continue;
+                       p->object.flags |= SEEN;
+                       insert_by_date(p, list);
+               }
+               return;
+       }
+
+       /*
+        * Ok, the commit wasn't uninteresting. Try to
+        * simplify the commit history and find the parent
+        * that has no differences in the path set if one exists.
+        */
+       if (revs->paths)
+               try_to_simplify_commit(revs, commit);
+
+       parent = commit->parents;
+       while (parent) {
+               struct commit *p = parent->item;
+
+               parent = parent->next;
+
+               parse_commit(p);
+               if (p->object.flags & SEEN)
+                       continue;
+               p->object.flags |= SEEN;
+               insert_by_date(p, list);
+       }
+}
+
+static void limit_list(struct rev_info *revs)
+{
+       struct commit_list *list = revs->commits;
+       struct commit_list *newlist = NULL;
+       struct commit_list **p = &newlist;
+
+       if (revs->paths)
+               diff_tree_setup_paths(revs->paths);
+
+       while (list) {
+               struct commit_list *entry = list;
+               struct commit *commit = list->item;
+               struct object *obj = &commit->object;
+
+               list = list->next;
+               free(entry);
+
+               if (revs->max_age != -1 && (commit->date < revs->max_age))
+                       obj->flags |= UNINTERESTING;
+               if (revs->unpacked && has_sha1_pack(obj->sha1))
+                       obj->flags |= UNINTERESTING;
+               add_parents_to_list(revs, commit, &list);
+               if (obj->flags & UNINTERESTING) {
+                       mark_parents_uninteresting(commit);
+                       if (everybody_uninteresting(list))
+                               break;
+                       continue;
+               }
+               if (revs->min_age != -1 && (commit->date > revs->min_age))
+                       continue;
+               p = &commit_list_insert(commit, p)->next;
+       }
+       revs->commits = newlist;
+}
+
 static void add_one_commit(struct commit *commit, struct rev_info *revs)
 {
        if (!commit || (commit->object.flags & SEEN))
@@ -212,13 +439,13 @@ static void handle_all(struct rev_info *revs, unsigned flags)
  * Parse revision information, filling in the "rev_info" structure,
  * and removing the used arguments from the argument list.
  *
- * Returns the number of arguments left ("new argc").
+ * Returns the number of arguments left that weren't recognized
+ * (which are also moved to the head of the argument list)
  */
-int setup_revisions(int argc, const char **argv, struct rev_info *revs)
+int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 {
        int i, flags, seen_dashdash;
-       const char *def = NULL;
-       const char **unrecognized = argv+1;
+       const char **unrecognized = argv + 1;
        int left = 1;
 
        memset(revs, 0, sizeof(*revs));
@@ -255,6 +482,21 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs)
                                revs->max_count = atoi(arg + 12);
                                continue;
                        }
+                       /* accept -<digit>, like traditilnal "head" */
+                       if ((*arg == '-') && isdigit(arg[1])) {
+                               revs->max_count = atoi(arg + 1);
+                               continue;
+                       }
+                       if (!strcmp(arg, "-n")) {
+                               if (argc <= i + 1)
+                                       die("-n requires an argument");
+                               revs->max_count = atoi(argv[++i]);
+                               continue;
+                       }
+                       if (!strncmp(arg,"-n",2)) {
+                               revs->max_count = atoi(arg + 2);
+                               continue;
+                       }
                        if (!strncmp(arg, "--max-age=", 10)) {
                                revs->max_age = atoi(arg + 10);
                                revs->limited = 1;
@@ -265,6 +507,26 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs)
                                revs->limited = 1;
                                continue;
                        }
+                       if (!strncmp(arg, "--since=", 8)) {
+                               revs->max_age = approxidate(arg + 8);
+                               revs->limited = 1;
+                               continue;
+                       }
+                       if (!strncmp(arg, "--after=", 8)) {
+                               revs->max_age = approxidate(arg + 8);
+                               revs->limited = 1;
+                               continue;
+                       }
+                       if (!strncmp(arg, "--before=", 9)) {
+                               revs->min_age = approxidate(arg + 9);
+                               revs->limited = 1;
+                               continue;
+                       }
+                       if (!strncmp(arg, "--until=", 8)) {
+                               revs->min_age = approxidate(arg + 8);
+                               revs->limited = 1;
+                               continue;
+                       }
                        if (!strcmp(arg, "--all")) {
                                handle_all(revs, flags);
                                continue;
@@ -302,6 +564,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs)
                                revs->remove_empty_trees = 1;
                                continue;
                        }
+                       if (!strncmp(arg, "--no-merges", 11)) {
+                               revs->no_merges = 1;
+                               continue;
+                       }
                        if (!strcmp(arg, "--objects")) {
                                revs->tag_objects = 1;
                                revs->tree_objects = 1;
@@ -378,6 +644,79 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs)
        }
        if (revs->paths)
                revs->limited = 1;
-       *unrecognized = NULL;
        return left;
 }
+
+void prepare_revision_walk(struct rev_info *revs)
+{
+       sort_by_date(&revs->commits);
+       if (revs->limited)
+               limit_list(revs);
+       if (revs->topo_order)
+               sort_in_topological_order(&revs->commits, revs->lifo);
+}
+
+static int rewrite_one(struct commit **pp)
+{
+       for (;;) {
+               struct commit *p = *pp;
+               if (p->object.flags & (TREECHANGE | UNINTERESTING))
+                       return 0;
+               if (!p->parents)
+                       return -1;
+               *pp = p->parents->item;
+       }
+}
+
+static void rewrite_parents(struct commit *commit)
+{
+       struct commit_list **pp = &commit->parents;
+       while (*pp) {
+               struct commit_list *parent = *pp;
+               if (rewrite_one(&parent->item) < 0) {
+                       *pp = parent->next;
+                       continue;
+               }
+               pp = &parent->next;
+       }
+}
+
+struct commit *get_revision(struct rev_info *revs)
+{
+       struct commit_list *list = revs->commits;
+       struct commit *commit;
+
+       if (!list)
+               return NULL;
+
+       /* Check the max_count ... */
+       commit = list->item;
+       switch (revs->max_count) {
+       case -1:
+               break;
+       case 0:
+               return NULL;
+       default:
+               revs->max_count--;
+       }
+
+       do {
+               commit = pop_most_recent_commit(&revs->commits, SEEN);
+               if (commit->object.flags & (UNINTERESTING|SHOWN))
+                       continue;
+               if (revs->min_age != -1 && (commit->date > revs->min_age))
+                       continue;
+               if (revs->max_age != -1 && (commit->date < revs->max_age))
+                       return NULL;
+               if (revs->no_merges && commit->parents && commit->parents->next)
+                       continue;
+               if (revs->paths && revs->dense) {
+                       if (!(commit->object.flags & TREECHANGE))
+                               continue;
+                       rewrite_parents(commit);
+               }
+               commit->object.flags |= SHOWN;
+               return commit;
+       } while (revs->commits);
+       return NULL;
+}