Merge branch 'jk/diff-result-code-cleanup'

"git diff --no-such-option" and other corner cases around the exit
status of the "diff" command has been corrected.

* jk/diff-result-code-cleanup:
  diff: drop useless "status" parameter from diff_result_code()
  diff: drop useless return values in git-diff helpers
  diff: drop useless return from run_diff_{files,index} functions
  diff: die when failing to read index in git-diff builtin
  diff: show usage for unknown builtin_diff_files() options
  diff-files: avoid negative exit value
  diff: spell DIFF_INDEX_CACHED out when calling run_diff_index()

add-interactive.c

@@ -569,7 +569,7 @@ static int get_modified_files(struct repository *r,
 			copy_pathspec(&rev.prune_data, ps);
 
 		if (s.mode == FROM_INDEX)
-			run_diff_index(&rev, 1);
+			run_diff_index(&rev, DIFF_INDEX_CACHED);
 		else {
 			rev.diffopt.flags.ignore_dirty_submodules = 1;
 			run_diff_files(&rev, 0);

builtin/add.c

@@ -194,8 +194,7 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	out = xopen(file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
 	rev.diffopt.file = xfdopen(out, "w");
 	rev.diffopt.close_file = 1;
-	if (run_diff_files(&rev, 0))
-		die(_("Could not write patch"));
+	run_diff_files(&rev, 0);
 
 	if (launch_editor(file, NULL, NULL))
 		die(_("editing patch failed"));

builtin/am.c

@@ -1430,7 +1430,7 @@ static void write_index_patch(const struct am_state *state)
 	rev_info.diffopt.close_file = 1;
 	add_pending_object(&rev_info, &tree->object, "");
 	diff_setup_done(&rev_info.diffopt);
-	run_diff_index(&rev_info, 1);
+	run_diff_index(&rev_info, DIFF_INDEX_CACHED);
 	release_revisions(&rev_info);
 }
 
@@ -1593,7 +1593,7 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
 		rev_info.diffopt.filter |= diff_filter_bit('M');
 		add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
 		diff_setup_done(&rev_info.diffopt);
-		run_diff_index(&rev_info, 1);
+		run_diff_index(&rev_info, DIFF_INDEX_CACHED);
 		release_revisions(&rev_info);
 	}
 

builtin/describe.c

@@ -668,7 +668,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			struct lock_file index_lock = LOCK_INIT;
 			struct rev_info revs;
 			struct strvec args = STRVEC_INIT;
-			int fd, result;
+			int fd;
 
 			setup_work_tree();
 			prepare_repo_settings(the_repository);
@@ -685,9 +685,9 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			strvec_pushv(&args, diff_index_args);
 			if (setup_revisions(args.nr, args.v, &revs, NULL) != 1)
 				BUG("malformed internal diff-index command line");
-			result = run_diff_index(&revs, 0);
+			run_diff_index(&revs, 0);
 
-			if (!diff_result_code(&revs.diffopt, result))
+			if (!diff_result_code(&revs.diffopt))
 				suffix = NULL;
 			else
 				suffix = dirty;

builtin/diff-files.c

@@ -80,14 +80,10 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
 	    (rev.diffopt.output_format & DIFF_FORMAT_PATCH))
 		diff_merges_set_dense_combined_if_unset(&rev);
 
-	if (repo_read_index_preload(the_repository, &rev.diffopt.pathspec, 0) < 0) {
-		perror("repo_read_index_preload");
-		result = -1;
-		goto cleanup;
-	}
-	result = run_diff_files(&rev, options);
-	result = diff_result_code(&rev.diffopt, result);
-cleanup:
+	if (repo_read_index_preload(the_repository, &rev.diffopt.pathspec, 0) < 0)
+		die_errno("repo_read_index_preload");
+	run_diff_files(&rev, options);
+	result = diff_result_code(&rev.diffopt);
 	release_revisions(&rev);
 	return result;
 }

builtin/diff-index.c

@@ -72,8 +72,8 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
 		perror("repo_read_index");
 		return -1;
 	}
-	result = run_diff_index(&rev, option);
-	result = diff_result_code(&rev.diffopt, result);
+	run_diff_index(&rev, option);
+	result = diff_result_code(&rev.diffopt);
 	release_revisions(&rev);
 	return result;
 }

builtin/diff-tree.c

@@ -232,5 +232,5 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 		diff_free(&opt->diffopt);
 	}
 
-	return diff_result_code(&opt->diffopt, 0);
+	return diff_result_code(&opt->diffopt);
 }

builtin/diff.c

@@ -77,9 +77,9 @@ static void stuff_change(struct diff_options *opt,
 	diff_queue(&diff_queued_diff, one, two);
 }
 
-static int builtin_diff_b_f(struct rev_info *revs,
-			    int argc, const char **argv UNUSED,
-			    struct object_array_entry **blob)
+static void builtin_diff_b_f(struct rev_info *revs,
+			     int argc, const char **argv UNUSED,
+			     struct object_array_entry **blob)
 {
 	/* Blob vs file in the working tree*/
 	struct stat st;
@@ -109,12 +109,11 @@ static int builtin_diff_b_f(struct rev_info *revs,
 		     path);
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
-	return 0;
 }
 
-static int builtin_diff_blobs(struct rev_info *revs,
-			      int argc, const char **argv UNUSED,
-			      struct object_array_entry **blob)
+static void builtin_diff_blobs(struct rev_info *revs,
+			       int argc, const char **argv UNUSED,
+			       struct object_array_entry **blob)
 {
 	const unsigned mode = canon_mode(S_IFREG | 0644);
 
@@ -134,11 +133,10 @@ static int builtin_diff_blobs(struct rev_info *revs,
 		     blob_path(blob[0]), blob_path(blob[1]));
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
-	return 0;
 }
 
-static int builtin_diff_index(struct rev_info *revs,
-			      int argc, const char **argv)
+static void builtin_diff_index(struct rev_info *revs,
+			       int argc, const char **argv)
 {
 	unsigned int option = 0;
 	while (1 < argc) {
@@ -163,20 +161,18 @@ static int builtin_diff_index(struct rev_info *revs,
 		setup_work_tree();
 		if (repo_read_index_preload(the_repository,
 					    &revs->diffopt.pathspec, 0) < 0) {
-			perror("repo_read_index_preload");
-			return -1;
+			die_errno("repo_read_index_preload");
 		}
 	} else if (repo_read_index(the_repository) < 0) {
-		perror("repo_read_cache");
-		return -1;
+		die_errno("repo_read_cache");
 	}
-	return run_diff_index(revs, option);
+	run_diff_index(revs, option);
 }
 
-static int builtin_diff_tree(struct rev_info *revs,
-			     int argc, const char **argv,
-			     struct object_array_entry *ent0,
-			     struct object_array_entry *ent1)
+static void builtin_diff_tree(struct rev_info *revs,
+			      int argc, const char **argv,
+			      struct object_array_entry *ent0,
+			      struct object_array_entry *ent1)
 {
 	const struct object_id *(oid[2]);
 	struct object_id mb_oid;
@@ -209,13 +205,12 @@ static int builtin_diff_tree(struct rev_info *revs,
 	}
 	diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
 	log_tree_diff_flush(revs);
-	return 0;
 }
 
-static int builtin_diff_combined(struct rev_info *revs,
-				 int argc, const char **argv UNUSED,
-				 struct object_array_entry *ent,
-				 int ents, int first_non_parent)
+static void builtin_diff_combined(struct rev_info *revs,
+				  int argc, const char **argv UNUSED,
+				  struct object_array_entry *ent,
+				  int ents, int first_non_parent)
 {
 	struct oid_array parents = OID_ARRAY_INIT;
 	int i;
@@ -236,7 +231,6 @@ static int builtin_diff_combined(struct rev_info *revs,
 	}
 	diff_tree_combined(&ent[first_non_parent].item->oid, &parents, revs);
 	oid_array_clear(&parents);
-	return 0;
 }
 
 static void refresh_index_quietly(void)
@@ -254,7 +248,7 @@ static void refresh_index_quietly(void)
 	repo_update_index_if_able(the_repository, &lock_file);
 }
 
-static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
+static void builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 {
 	unsigned int options = 0;
 
@@ -269,8 +263,10 @@ static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv
 			options |= DIFF_SILENT_ON_REMOVED;
 		else if (!strcmp(argv[1], "-h"))
 			usage(builtin_diff_usage);
-		else
-			return error(_("invalid option: %s"), argv[1]);
+		else {
+			error(_("invalid option: %s"), argv[1]);
+			usage(builtin_diff_usage);
+		}
 		argv++; argc--;
 	}
 
@@ -287,10 +283,9 @@ static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv
 	setup_work_tree();
 	if (repo_read_index_preload(the_repository, &revs->diffopt.pathspec,
 				    0) < 0) {
-		perror("repo_read_index_preload");
-		return -1;
+		die_errno("repo_read_index_preload");
 	}
-	return run_diff_files(revs, options);
+	run_diff_files(revs, options);
 }
 
 struct symdiff {
@@ -404,7 +399,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	int blobs = 0, paths = 0;
 	struct object_array_entry *blob[2];
 	int nongit = 0, no_index = 0;
-	int result = 0;
+	int result;
 	struct symdiff sdiff;
 
 	/*
@@ -583,17 +578,17 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	if (!ent.nr) {
 		switch (blobs) {
 		case 0:
-			result = builtin_diff_files(&rev, argc, argv);
+			builtin_diff_files(&rev, argc, argv);
 			break;
 		case 1:
 			if (paths != 1)
 				usage(builtin_diff_usage);
-			result = builtin_diff_b_f(&rev, argc, argv, blob);
+			builtin_diff_b_f(&rev, argc, argv, blob);
 			break;
 		case 2:
 			if (paths)
 				usage(builtin_diff_usage);
-			result = builtin_diff_blobs(&rev, argc, argv, blob);
+			builtin_diff_blobs(&rev, argc, argv, blob);
 			break;
 		default:
 			usage(builtin_diff_usage);
@@ -602,18 +597,18 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	else if (blobs)
 		usage(builtin_diff_usage);
 	else if (ent.nr == 1)
-		result = builtin_diff_index(&rev, argc, argv);
+		builtin_diff_index(&rev, argc, argv);
 	else if (ent.nr == 2) {
 		if (sdiff.warn)
 			warning(_("%s...%s: multiple merge bases, using %s"),
 				sdiff.left, sdiff.right, sdiff.base);
-		result = builtin_diff_tree(&rev, argc, argv,
-					   &ent.objects[0], &ent.objects[1]);
+		builtin_diff_tree(&rev, argc, argv,
+				  &ent.objects[0], &ent.objects[1]);
 	} else
-		result = builtin_diff_combined(&rev, argc, argv,
-					       ent.objects, ent.nr,
-					       first_non_parent);
-	result = diff_result_code(&rev.diffopt, result);
+		builtin_diff_combined(&rev, argc, argv,
+				      ent.objects, ent.nr,
+				      first_non_parent);
+	result = diff_result_code(&rev.diffopt);
 	if (1 < rev.diffopt.skip_stat_unmatch)
 		refresh_index_quietly();
 	release_revisions(&rev);

builtin/log.c

@@ -549,7 +549,7 @@ static int cmd_log_walk_no_free(struct rev_info *rev)
 	    rev->diffopt.flags.check_failed) {
 		return 02;
 	}
-	return diff_result_code(&rev->diffopt, 0);
+	return diff_result_code(&rev->diffopt);
 }
 
 static int cmd_log_walk(struct rev_info *rev)

builtin/stash.c

@@ -973,7 +973,7 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	}
 	log_tree_diff_flush(&rev);
 
-	ret = diff_result_code(&rev.diffopt, 0);
+	ret = diff_result_code(&rev.diffopt);
 cleanup:
 	strvec_clear(&stash_args);
 	free_stash_info(&info);
@@ -1089,7 +1089,6 @@ static int get_untracked_files(const struct pathspec *ps, int include_untracked,
  */
 static int check_changes_tracked_files(const struct pathspec *ps)
 {
-	int result;
 	struct rev_info rev;
 	struct object_id dummy;
 	int ret = 0;
@@ -1111,14 +1110,14 @@ static int check_changes_tracked_files(const struct pathspec *ps)
 	add_head_to_pending(&rev);
 	diff_setup_done(&rev.diffopt);
 
-	result = run_diff_index(&rev, 1);
-	if (diff_result_code(&rev.diffopt, result)) {
+	run_diff_index(&rev, DIFF_INDEX_CACHED);
+	if (diff_result_code(&rev.diffopt)) {
 		ret = 1;
 		goto done;
 	}
 
-	result = run_diff_files(&rev, 0);
-	if (diff_result_code(&rev.diffopt, result)) {
+	run_diff_files(&rev, 0);
+	if (diff_result_code(&rev.diffopt)) {
 		ret = 1;
 		goto done;
 	}
@@ -1309,10 +1308,7 @@ static int stash_working_tree(struct stash_info *info, const struct pathspec *ps
 
 	add_pending_object(&rev, parse_object(the_repository, &info->b_commit),
 			   "");
-	if (run_diff_index(&rev, 0)) {
-		ret = -1;
-		goto done;
-	}
+	run_diff_index(&rev, 0);
 
 	cp_upd_index.git_cmd = 1;
 	strvec_pushl(&cp_upd_index.args, "update-index",

builtin/submodule--helper.c

@@ -629,7 +629,6 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 	char *displaypath;
 	struct strvec diff_files_args = STRVEC_INIT;
 	struct rev_info rev = REV_INFO_INIT;
-	int diff_files_result;
 	struct strbuf buf = STRBUF_INIT;
 	const char *git_dir;
 	struct setup_revision_opt opt = {
@@ -669,9 +668,9 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 	repo_init_revisions(the_repository, &rev, NULL);
 	rev.abbrev = 0;
 	setup_revisions(diff_files_args.nr, diff_files_args.v, &rev, &opt);
-	diff_files_result = run_diff_files(&rev, 0);
+	run_diff_files(&rev, 0);
 
-	if (!diff_result_code(&rev.diffopt, diff_files_result)) {
+	if (!diff_result_code(&rev.diffopt)) {
 		print_status(flags, ' ', path, ce_oid,
 			     displaypath);
 	} else if (!(flags & OPT_CACHED)) {
@@ -1141,7 +1140,7 @@ static int compute_summary_module_list(struct object_id *head_oid,
 	}
 
 	if (diff_cmd == DIFF_INDEX)
-		run_diff_index(&rev, info->cached);
+		run_diff_index(&rev, info->cached ? DIFF_INDEX_CACHED : 0);
 	else
 		run_diff_files(&rev, 0);
 	prepare_submodule_summary(info, &list);