Merge branch 'jc/diff-index-unpack' into maint

* jc/diff-index-unpack:
  diff-index: pass pathspec down to unpack-trees machinery
  unpack-trees: allow pruning with pathspec
  traverse_trees(): allow pruning with pathspec

diff --combined diff-lib.c
index f8454dd2918dc74bee43d9f2faa1837cc5665abd,12760b422f83e0c08d4ad9af5419318e9d47bcaa..ebe751e72d0ca9db2f0a9d2576f3dc3f41ffc31d
--- 1/diff-lib.c
--- 2/diff-lib.c
+++ b/diff-lib.c
@@@ -379,8 -379,7 +379,8 @@@ static void do_oneway_diff(struct unpac
        if (cached && idx && ce_stage(idx)) {
                struct diff_filepair *pair;
                pair = diff_unmerge(&revs->diffopt, idx->name);
 -              fill_filespec(pair->one, idx->sha1, idx->ce_mode);
 +              if (tree)
 +                      fill_filespec(pair->one, tree->sha1, tree->ce_mode);
                return;
        }
  
@@@ -434,30 -433,26 +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;
@@@ -468,17 -463,10 +468,18 @@@
        opts.unpack_data = revs;
        opts.src_index = &the_index;
        opts.dst_index = NULL;
+       opts.pathspec = &revs->diffopt.pathspec;
  
        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/");
@@@ -490,13 -478,53 +491,13 @@@
  
  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));
 -
 -      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;
 +      revs.diffopt = *opt;
  
 -      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;
  }

diff --combined unpack-trees.c
index cc616c3f991a655d10fcac15055fcdfafa8620fd,d5ec463e0ef40a2b1276c1e73f0c3e9d908002d4..670b46473883505c39c5353c65e0eeb93aec21c3
--- 1/unpack-trees.c
--- 2/unpack-trees.c
+++ b/unpack-trees.c
@@@ -444,6 -444,7 +444,7 @@@ static int traverse_trees_recursive(in
  
        newinfo = *info;
        newinfo.prev = info;
+       newinfo.pathspec = info->pathspec;
        newinfo.name = *p;
        newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
        newinfo.conflicts |= df_conflicts;
@@@ -593,7 -594,7 +594,7 @@@ static int unpack_nondirectories(int n
  static int unpack_failed(struct unpack_trees_options *o, const char *message)
  {
        discard_index(&o->result);
 -      if (!o->gently) {
 +      if (!o->gently && !o->exiting_early) {
                if (message)
                        return error("%s", message);
                return -1;
@@@ -1040,6 -1041,7 +1041,7 @@@ int unpack_trees(unsigned len, struct t
                info.fn = unpack_callback;
                info.data = o;
                info.show_all_errors = o->show_all_errors;
+               info.pathspec = o->pathspec;
  
                if (o->prefix) {
                        /*
@@@ -1133,8 -1135,6 +1135,8 @@@ return_failed
                display_error_msgs(o);
        mark_all_ce_unused(o->src_index);
        ret = unpack_failed(o, NULL);
 +      if (o->exiting_early)
 +              ret = 0;
        goto done;
  }
  
@@@ -1168,22 -1168,11 +1170,22 @@@ static int verify_uptodate_1(struct cac
  {
        struct stat st;
  
 -      if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
 +      if (o->index_only)
 +              return 0;
 +
 +      /*
 +       * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again
 +       * if this entry is truly up-to-date because this file may be
 +       * overwritten.
 +       */
 +      if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
 +              ; /* keep checking */
 +      else if (o->reset || ce_uptodate(ce))
                return 0;
  
        if (!lstat(ce->name, &st)) {
 -              unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 +              int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
 +              unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
                if (!changed)
                        return 0;
                /*

diff --combined unpack-trees.h
index 79989483079970e9dad42512e522eef8ea2a75a4,b7fed7e6ecafb5c21bf8d6f4cffaa2847cfb54d8..5e432f576eb2304a63510a61a71182e11f777092
--- 1/unpack-trees.h
--- 2/unpack-trees.h
+++ b/unpack-trees.h
@@@ -46,12 -46,12 +46,13 @@@ struct unpack_trees_options 
                     debug_unpack,
                     skip_sparse_checkout,
                     gently,
 +                   exiting_early,
                     show_all_errors,
                     dry_run;
        const char *prefix;
        int cache_bottom;
        struct dir_struct *dir;
+       struct pathspec *pathspec;
        merge_fn_t fn;
        const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
        /*