Merge branch 'jc/diff-index-refactor'

* jc/diff-index-refactor:
diff-lib: refactor run_diff_index() and do_diff_cache()
diff-lib: simplify do_diff_cache()

diff --combined diff-lib.c
index b3797592c63a86b46a3af0d875b6fe04ea43f536,c7626554b85b7be3491eeaca32e534b6765dc5aa..f8454dd2918dc74bee43d9f2faa1837cc5665abd
--- 1/diff-lib.c
--- 2/diff-lib.c
+++ b/diff-lib.c
@@@ -434,31 -434,25 +434,30 @@@ static int oneway_diff(struct cache_ent
        if (tree == o->df_conflict_entry)
                tree = NULL;
  
 -      if (ce_path_match(idx ? idx : tree, &revs->prune_data))
 +      if (ce_path_match(idx ? idx : tree, &revs->prune_data)) {
                do_oneway_diff(o, idx, tree);
 +              if (diff_can_quit_early(&revs->diffopt)) {
 +                      o->exiting_early = 1;
 +                      return -1;
 +              }
 +      }
  
        return 0;
  }
  
- int run_diff_index(struct rev_info *revs, int cached)
+ static int diff_cache(struct rev_info *revs,
+                     const unsigned char *tree_sha1,
+                     const char *tree_name,
+                     int cached)
  {
-       struct object *ent;
        struct tree *tree;
-       const char *tree_name;
-       struct unpack_trees_options opts;
        struct tree_desc t;
+       struct unpack_trees_options opts;
  
-       ent = revs->pending.objects[0].item;
-       tree_name = revs->pending.objects[0].name;
-       tree = parse_tree_indirect(ent->sha1);
+       tree = parse_tree_indirect(tree_sha1);
        if (!tree)
-               return error("bad tree object %s", tree_name);
- 
+               return error("bad tree object %s",
+                            tree_name ? tree_name : sha1_to_hex(tree_sha1));
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = 1;
        opts.index_only = cached;
@@@ -471,7 -465,15 +470,15 @@@
        opts.dst_index = NULL;
  
        init_tree_desc(&t, tree->buffer, tree->size);
-       if (unpack_trees(1, &t, &opts))
+       return unpack_trees(1, &t, &opts);
+ }
+ 
+ int run_diff_index(struct rev_info *revs, int cached)
+ {
+       struct object_array_entry *ent;
+ 
+       ent = revs->pending.objects;
+       if (diff_cache(revs, ent->item->sha1, ent->name, cached))
                exit(128);
  
        diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
@@@ -483,53 -485,13 +490,13 @@@
  
  int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
  {
-       struct tree *tree;
        struct rev_info revs;
-       int i;
-       struct cache_entry **dst;
-       struct cache_entry *last = NULL;
-       struct unpack_trees_options opts;
-       struct tree_desc t;
- 
-       /*
-        * This is used by git-blame to run diff-cache internally;
-        * it potentially needs to repeatedly run this, so we will
-        * start by removing the higher order entries the last round
-        * left behind.
-        */
-       dst = active_cache;
-       for (i = 0; i < active_nr; i++) {
-               struct cache_entry *ce = active_cache[i];
-               if (ce_stage(ce)) {
-                       if (last && !strcmp(ce->name, last->name))
-                               continue;
-                       cache_tree_invalidate_path(active_cache_tree,
-                                                  ce->name);
-                       last = ce;
-                       ce->ce_flags |= CE_REMOVE;
-               }
-               *dst++ = ce;
-       }
-       active_nr = dst - active_cache;
  
        init_revisions(&revs, NULL);
        init_pathspec(&revs.prune_data, opt->pathspec.raw);
-       tree = parse_tree_indirect(tree_sha1);
-       if (!tree)
-               die("bad tree object %s", sha1_to_hex(tree_sha1));
+       revs.diffopt = *opt;
  
-       memset(&opts, 0, sizeof(opts));
-       opts.head_idx = 1;
-       opts.index_only = 1;
-       opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
-       opts.merge = 1;
-       opts.fn = oneway_diff;
-       opts.unpack_data = &revs;
-       opts.src_index = &the_index;
-       opts.dst_index = &the_index;
- 
-       init_tree_desc(&t, tree->buffer, tree->size);
-       if (unpack_trees(1, &t, &opts))
+       if (diff_cache(&revs, tree_sha1, NULL, 1))
                exit(128);
        return 0;
  }