Merge branch 'jk/format-patch-output'

"git format-patch --output=there" did not work as expected and
instead crashed.  The option is now supported.

* jk/format-patch-output:
  format-patch: support --output option
  format-patch: tie file-opening logic to output_directory
  format-patch: refactor output selection

builtin/log.c

@@ -1156,7 +1156,7 @@ static void get_notes_args(struct strvec *arg, struct rev_info *rev)
 	}
 }
 
-static void make_cover_letter(struct rev_info *rev, int use_stdout,
+static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 			      struct commit *origin,
 			      int nr, struct commit **list,
 			      const char *branch_name,
@@ -1176,7 +1176,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 
 	committer = git_committer_info(0);
 
-	if (!use_stdout &&
+	if (use_separate_file &&
 	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
 		die(_("failed to create cover-letter file"));
 
@@ -1945,20 +1945,27 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (rev.show_notes)
 		load_display_notes(&rev.notes_opt);
 
-	if (!output_directory && !use_stdout)
-		output_directory = config_output_directory;
+	if (use_stdout + rev.diffopt.close_file + !!output_directory > 1)
+		die(_("--stdout, --output, and --output-directory are mutually exclusive"));
 
-	if (!use_stdout)
-		output_directory = set_outdir(prefix, output_directory);
-	else
+	if (use_stdout) {
 		setup_pager();
-
-	if (output_directory) {
+	} else if (rev.diffopt.close_file) {
+		/*
+		 * The diff code parsed --output; it has already opened the
+		 * file, but but we must instruct it not to close after each
+		 * diff.
+		 */
+		rev.diffopt.close_file = 0;
+	} else {
 		int saved;
+
+		if (!output_directory)
+			output_directory = config_output_directory;
+		output_directory = set_outdir(prefix, output_directory);
+
 		if (rev.diffopt.use_color != GIT_COLOR_ALWAYS)
 			rev.diffopt.use_color = GIT_COLOR_NEVER;
-		if (use_stdout)
-			die(_("standard output, or directory, which one?"));
 		/*
 		 * We consider <outdir> as 'outside of gitdir', therefore avoid
 		 * applying adjust_shared_perm in s-c-l-d.
@@ -2120,7 +2127,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (cover_letter) {
 		if (thread)
 			gen_message_id(&rev, "cover");
-		make_cover_letter(&rev, use_stdout,
+		make_cover_letter(&rev, !!output_directory,
 				  origin, nr, list, branch_name, quiet);
 		print_bases(&bases, rev.diffopt.file);
 		print_signature(rev.diffopt.file);
@@ -2175,7 +2182,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			gen_message_id(&rev, oid_to_hex(&commit->object.oid));
 		}
 
-		if (!use_stdout &&
+		if (output_directory &&
 		    open_next_file(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
 			die(_("failed to create output files"));
 		shown = log_tree_commit(&rev, commit);
@@ -2188,7 +2195,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		 * the log; when using one file per patch, we do
 		 * not want the extra blank line.
 		 */
-		if (!use_stdout)
+		if (output_directory)
 			rev.shown_one = 0;
 		if (shown) {
 			print_bases(&bases, rev.diffopt.file);
@@ -2199,7 +2206,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			else
 				print_signature(rev.diffopt.file);
 		}
-		if (!use_stdout)
+		if (output_directory)
 			fclose(rev.diffopt.file);
 	}
 	stop_progress(&progress);

t/t4014-format-patch.sh

@@ -1919,6 +1919,39 @@ test_expect_success 'format-patch -o overrides format.outputDirectory' '
 	test_path_is_dir patchset
 '
 
+test_expect_success 'format-patch forbids multiple outputs' '
+	rm -fr outfile outdir &&
+	test_must_fail \
+		git format-patch --stdout --output-directory=outdir &&
+	test_must_fail \
+		git format-patch --stdout --output=outfile &&
+	test_must_fail \
+		git format-patch --output=outfile --output-directory=outdir
+'
+
+test_expect_success 'configured outdir does not conflict with output options' '
+	rm -fr outfile outdir &&
+	test_config format.outputDirectory outdir &&
+	git format-patch --stdout &&
+	test_path_is_missing outdir &&
+	git format-patch --output=outfile &&
+	test_path_is_missing outdir
+'
+
+test_expect_success 'format-patch --output' '
+	rm -fr outfile &&
+	git format-patch -3 --stdout HEAD >expect &&
+	git format-patch -3 --output=outfile HEAD &&
+	test_cmp expect outfile
+'
+
+test_expect_success 'format-patch --cover-letter --output' '
+	rm -fr outfile &&
+	git format-patch --cover-letter -3 --stdout HEAD >expect &&
+	git format-patch --cover-letter -3 --output=outfile HEAD &&
+	test_cmp expect outfile
+'
+
 test_expect_success 'format-patch --base' '
 	git checkout patchid &&