git-mv: fully detect 'directory moved into itself'

diff --git a/object.c b/object.c
index 72f6aa552f79edcd5f4f5c4a647ab62503365b1b..427e14cae2deb42138a439f7b2d69d3e06bb9417 100644 (file)
--- a/object.c
+++ b/object.c
@@ -9,6 +9,8 @@ struct object **objs;
 int nr_objs;
 static int obj_allocs;
 
+int track_object_refs = 1;
+
 static int find_object(const unsigned char *sha1)
 {
        int first = 0, last = nr_objs;
@@ -65,35 +67,66 @@ void created_object(const unsigned char *sha1, struct object *obj)
        nr_objs++;
 }
 
-void add_ref(struct object *refer, struct object *target)
+struct object_refs *alloc_object_refs(unsigned count)
+{
+       struct object_refs *refs;
+       size_t size = sizeof(*refs) + count*sizeof(struct object *);
+
+       refs = xmalloc(size);
+       memset(refs, 0, size);
+       refs->count = count;
+       return refs;
+}
+
+static int compare_object_pointers(const void *a, const void *b)
 {
-       struct object_list **pp = &refer->refs;
-       struct object_list *p;
-       
-       while ((p = *pp) != NULL) {
-               if (p->item == target)
-                       return;
-               pp = &p->next;
+       const struct object * const *pa = a;
+       const struct object * const *pb = b;
+       return *pa - *pb;
+}
+
+void set_object_refs(struct object *obj, struct object_refs *refs)
+{
+       unsigned int i, j;
+
+       /* Do not install empty list of references */
+       if (refs->count < 1) {
+               free(refs);
+               return;
        }
 
-       target->used = 1;
-       p = xmalloc(sizeof(*p));
-       p->item = target;
-       p->next = NULL;
-       *pp = p;
+       /* Sort the list and filter out duplicates */
+       qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
+             compare_object_pointers);
+       for (i = j = 1; i < refs->count; i++) {
+               if (refs->ref[i] != refs->ref[i - 1])
+                       refs->ref[j++] = refs->ref[i];
+       }
+       if (j < refs->count) {
+               /* Duplicates were found - reallocate list */
+               size_t size = sizeof(*refs) + j*sizeof(struct object *);
+               refs->count = j;
+               refs = xrealloc(refs, size);
+       }
+
+       for (i = 0; i < refs->count; i++)
+               refs->ref[i]->used = 1;
+       obj->refs = refs;
 }
 
 void mark_reachable(struct object *obj, unsigned int mask)
 {
-       struct object_list *p = obj->refs;
-
+       if (!track_object_refs)
+               die("cannot do reachability with object refs turned off");
        /* If we've been here already, don't bother */
        if (obj->flags & mask)
                return;
        obj->flags |= mask;
-       while (p) {
-               mark_reachable(p->item, mask);
-               p = p->next;
+       if (obj->refs) {
+               const struct object_refs *refs = obj->refs;
+               unsigned i;
+               for (i = 0; i < refs->count; i++)
+                       mark_reachable(refs->ref[i], mask);
        }
 }
 
@@ -184,6 +217,17 @@ struct object_list *object_list_insert(struct object *item,
         return new_list;
 }
 
+void object_list_append(struct object *item,
+                       struct object_list **list_p)
+{
+       while (*list_p) {
+               list_p = &((*list_p)->next);
+       }
+       *list_p = xmalloc(sizeof(struct object_list));
+       (*list_p)->next = NULL;
+       (*list_p)->item = item;
+}
+
 unsigned object_list_length(struct object_list *list)
 {
        unsigned ret = 0;