1 files changed, 128 insertions, 35 deletions

diff --git a/diff-lib.c b/diff-lib.c
index 88a98b1c06..b73cc1859a 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -13,6 +13,7 @@
 #include "submodule.h"
 #include "dir.h"
 #include "fsmonitor.h"
+#include "commit-reach.h"
 
 /*
  * diff-files
@@ -70,7 +71,7 @@ static int match_stat_with_submodule(struct diff_options *diffopt,
 				     struct stat *st, unsigned ce_option,
 				     unsigned *dirty_submodule)
 {
-	int changed = ce_match_stat(ce, st, ce_option);
+	int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
 	if (S_ISGITLINK(ce->ce_mode)) {
 		struct diff_flags orig_flags = diffopt->flags;
 		if (!diffopt->flags.override_submodule_config)
@@ -93,15 +94,18 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 	unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 			      ? CE_MATCH_RACY_IS_DIRTY : 0);
 	uint64_t start = getnanotime();
+	struct index_state *istate = revs->diffopt.repo->index;
 
 	diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 
+	refresh_fsmonitor(istate);
+
 	if (diff_unmerged_stage < 0)
 		diff_unmerged_stage = 2;
-	entries = active_nr;
+	entries = istate->cache_nr;
 	for (i = 0; i < entries; i++) {
 		unsigned int oldmode, newmode;
-		struct cache_entry *ce = active_cache[i];
+		struct cache_entry *ce = istate->cache[i];
 		int changed;
 		unsigned dirty_submodule = 0;
 		const struct object_id *old_oid, *new_oid;
@@ -109,7 +113,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		if (diff_can_quit_early(&revs->diffopt))
 			break;
 
-		if (!ce_path_match(&the_index, ce, &revs->prune_data, NULL))
+		if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
 			continue;
 
 		if (ce_stage(ce)) {
@@ -145,7 +149,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			dpath->mode = wt_mode;
 
 			while (i < entries) {
-				struct cache_entry *nce = active_cache[i];
+				struct cache_entry *nce = istate->cache[i];
 				int stage;
 
 				if (strcmp(ce->name, nce->name))
@@ -176,9 +180,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			i--;
 
 			if (revs->combine_merges && num_compare_stages == 2) {
-				show_combined_diff(dpath, 2,
-						   revs->dense_combined_merges,
-						   revs);
+				show_combined_diff(dpath, 2, revs);
 				free(dpath);
 				continue;
 			}
@@ -198,8 +200,17 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		if (ce_uptodate(ce) || ce_skip_worktree(ce))
 			continue;
 
-		/* If CE_VALID is set, don't look at workdir for file removal */
-		if (ce->ce_flags & CE_VALID) {
+		/*
+		 * When CE_VALID is set (via "update-index --assume-unchanged"
+		 * or via adding paths while core.ignorestat is set to true),
+		 * the user has promised that the working tree file for that
+		 * path will not be modified.  When CE_FSMONITOR_VALID is true,
+		 * the fsmonitor knows that the path hasn't been modified since
+		 * we refreshed the cached stat information.  In either case,
+		 * we do not have to stat to see if the path has been removed
+		 * or modified.
+		 */
+		if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 			changed = 0;
 			newmode = ce->ce_mode;
 		} else {
@@ -218,9 +229,9 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 				continue;
 			} else if (revs->diffopt.ita_invisible_in_index &&
 				   ce_intent_to_add(ce)) {
-				diff_addremove(&revs->diffopt, '+', ce->ce_mode,
-					       the_hash_algo->empty_tree, 0,
-					       ce->name, 0);
+				newmode = ce_mode_from_stat(ce, st.st_mode);
+				diff_addremove(&revs->diffopt, '+', newmode,
+					       &null_oid, 0, ce->name, 0);
 				continue;
 			}
 
@@ -231,7 +242,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 
 		if (!changed && !dirty_submodule) {
 			ce_mark_uptodate(ce);
-			mark_fsmonitor_valid(ce);
+			mark_fsmonitor_valid(istate, ce);
 			if (!revs->diffopt.flags.find_copies_harder)
 				continue;
 		}
@@ -342,7 +353,7 @@ static int show_modified(struct rev_info *revs,
 	}
 
 	if (revs->combine_merges && !cached &&
-	    (oidcmp(oid, &old_entry->oid) || oidcmp(&old_entry->oid, &new_entry->oid))) {
+	    (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 		struct combine_diff_path *p;
 		int pathlen = ce_namelen(new_entry);
 
@@ -360,13 +371,13 @@ static int show_modified(struct rev_info *revs,
 		p->parent[1].status = DIFF_STATUS_MODIFIED;
 		p->parent[1].mode = old_entry->ce_mode;
 		oidcpy(&p->parent[1].oid, &old_entry->oid);
-		show_combined_diff(p, 2, revs->dense_combined_merges, revs);
+		show_combined_diff(p, 2, revs);
 		free(p);
 		return 0;
 	}
 
 	oldmode = old_entry->ce_mode;
-	if (mode == oldmode && !oidcmp(oid, &old_entry->oid) && !dirty_submodule &&
+	if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 	    !revs->diffopt.flags.find_copies_harder)
 		return 0;
 
@@ -404,14 +415,8 @@ static void do_oneway_diff(struct unpack_trees_options *o,
 	/* if the entry is not checked out, don't examine work tree */
 	cached = o->index_only ||
 		(idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
-	/*
-	 * Backward compatibility wart - "diff-index -m" does
-	 * not mean "do not ignore merges", but "match_missing".
-	 *
-	 * But with the revision flag parsing, that's found in
-	 * "!revs->ignore_merges".
-	 */
-	match_missing = !revs->ignore_merges;
+
+	match_missing = revs->match_missing;
 
 	if (cached && idx && ce_stage(idx)) {
 		struct diff_filepair *pair;
@@ -474,7 +479,9 @@ static int oneway_diff(const struct cache_entry * const *src,
 	if (tree == o->df_conflict_entry)
 		tree = NULL;
 
-	if (ce_path_match(&the_index, idx ? idx : tree, &revs->prune_data, NULL)) {
+	if (ce_path_match(revs->diffopt.repo->index,
+			  idx ? idx : tree,
+			  &revs->prune_data, NULL)) {
 		do_oneway_diff(o, idx, tree);
 		if (diff_can_quit_early(&revs->diffopt)) {
 			o->exiting_early = 1;
@@ -506,7 +513,7 @@ static int diff_cache(struct rev_info *revs,
 	opts.merge = 1;
 	opts.fn = oneway_diff;
 	opts.unpack_data = revs;
-	opts.src_index = &the_index;
+	opts.src_index = revs->diffopt.repo->index;
 	opts.dst_index = NULL;
 	opts.pathspec = &revs->diffopt.pathspec;
 	opts.pathspec->recursive = 1;
@@ -515,23 +522,81 @@ static int diff_cache(struct rev_info *revs,
 	return unpack_trees(1, &t, &opts);
 }
 
-int run_diff_index(struct rev_info *revs, int cached)
+void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
+{
+	int i;
+	struct commit *mb_child[2] = {0};
+	struct commit_list *merge_bases;
+
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object *obj = revs->pending.objects[i].item;
+		if (obj->flags)
+			die(_("--merge-base does not work with ranges"));
+		if (obj->type != OBJ_COMMIT)
+			die(_("--merge-base only works with commits"));
+	}
+
+	/*
+	 * This check must go after the for loop above because A...B
+	 * ranges produce three pending commits, resulting in a
+	 * misleading error message.
+	 */
+	if (revs->pending.nr < 1 || revs->pending.nr > 2)
+		BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
+
+	for (i = 0; i < revs->pending.nr; i++)
+		mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
+	if (revs->pending.nr == 1) {
+		struct object_id oid;
+
+		if (get_oid("HEAD", &oid))
+			die(_("unable to get HEAD"));
+
+		mb_child[1] = lookup_commit_reference(the_repository, &oid);
+	}
+
+	merge_bases = repo_get_merge_bases(the_repository, mb_child[0], mb_child[1]);
+	if (!merge_bases)
+		die(_("no merge base found"));
+	if (merge_bases->next)
+		die(_("multiple merge bases found"));
+
+	oidcpy(mb, &merge_bases->item->object.oid);
+
+	free_commit_list(merge_bases);
+}
+
+int run_diff_index(struct rev_info *revs, unsigned int option)
 {
 	struct object_array_entry *ent;
-	uint64_t start = getnanotime();
+	int cached = !!(option & DIFF_INDEX_CACHED);
+	int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
+	struct object_id oid;
+	const char *name;
+	char merge_base_hex[GIT_MAX_HEXSZ + 1];
 
 	if (revs->pending.nr != 1)
 		BUG("run_diff_index must be passed exactly one tree");
 
+	trace_performance_enter();
 	ent = revs->pending.objects;
-	if (diff_cache(revs, &ent->item->oid, ent->name, cached))
+
+	if (merge_base) {
+		diff_get_merge_base(revs, &oid);
+		name = oid_to_hex_r(merge_base_hex, &oid);
+	} else {
+		oidcpy(&oid, &ent->item->oid);
+		name = ent->name;
+	}
+
+	if (diff_cache(revs, &oid, name, cached))
 		exit(128);
 
 	diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
-	diffcore_fix_diff_index(&revs->diffopt);
+	diffcore_fix_diff_index();
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
-	trace_performance_since(start, "diff-index");
+	trace_performance_leave("diff-index");
 	return 0;
 }
 
@@ -539,22 +604,25 @@ int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 {
 	struct rev_info revs;
 
-	init_revisions(&revs, NULL);
+	repo_init_revisions(opt->repo, &revs, NULL);
 	copy_pathspec(&revs.prune_data, &opt->pathspec);
+	diff_setup_done(&revs.diffopt);
 	revs.diffopt = *opt;
 
 	if (diff_cache(&revs, tree_oid, NULL, 1))
 		exit(128);
+	clear_pathspec(&revs.prune_data);
 	return 0;
 }
 
-int index_differs_from(const char *def, const struct diff_flags *flags,
+int index_differs_from(struct repository *r,
+		       const char *def, const struct diff_flags *flags,
 		       int ita_invisible_in_index)
 {
 	struct rev_info rev;
 	struct setup_revision_opt opt;
 
-	init_revisions(&rev, NULL);
+	repo_init_revisions(r, &rev, NULL);
 	memset(&opt, 0, sizeof(opt));
 	opt.def = def;
 	setup_revisions(0, NULL, &rev, &opt);
@@ -567,3 +635,28 @@ int index_differs_from(const char *def, const struct diff_flags *flags,
 	object_array_clear(&rev.pending);
 	return (rev.diffopt.flags.has_changes != 0);
 }
+
+static struct strbuf *idiff_prefix_cb(struct diff_options *opt, void *data)
+{
+	return data;
+}
+
+void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
+		    int indent, struct diff_options *diffopt)
+{
+	struct diff_options opts;
+	struct strbuf prefix = STRBUF_INIT;
+
+	memcpy(&opts, diffopt, sizeof(opts));
+	opts.output_format = DIFF_FORMAT_PATCH;
+	opts.output_prefix = idiff_prefix_cb;
+	strbuf_addchars(&prefix, ' ', indent);
+	opts.output_prefix_data = &prefix;
+	diff_setup_done(&opts);
+
+	diff_tree_oid(oid1, oid2, "", &opts);
+	diffcore_std(&opts);
+	diff_flush(&opts);
+
+	strbuf_release(&prefix);
+}