format-patch: introduce format.outputDirectory configuration

We can pass -o/--output-directory to the format-patch command to store
patches in some place other than the working directory. This patch
introduces format.outputDirectory configuration option for same
purpose.

The case of usage of this configuration option can be convenience
to not pass every time -o/--output-directory if an user has pattern
to store all patches in the /patches directory for example.

The format.outputDirectory has lower priority than command line
option, so if user will set format.outputDirectory and pass the
command line option, a result will be stored in a directory that
passed to command line option.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Stephen P. Smith <ischis2@cox.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -1243,6 +1243,10 @@ format.coverLetter::
 	format-patch is invoked, but in addition can be set to "auto", to
 	generate a cover-letter only when there's more than one patch.
 
+format.outputDirectory::
+	Set a custom directory to store the resulting files instead of the
+	current working directory.
+
 filter.<driver>.clean::
 	The command which is used to convert the content of a worktree
 	file to a blob upon checkin.  See linkgit:gitattributes[5] for

Documentation/git-format-patch.txt

@@ -57,7 +57,11 @@ The names of the output files are printed to standard
 output, unless the `--stdout` option is specified.
 
 If `-o` is specified, output files are created in <dir>.  Otherwise
-they are created in the current working directory.
+they are created in the current working directory. The default path
+can be set with the 'format.outputDirectory' configuration option.
+The `-o` option takes precedence over `format.outputDirectory`.
+To store patches in the current working directory even when
+`format.outputDirectory` points elsewhere, use `-o .`.
 
 By default, the subject of a single patch is "[PATCH] " followed by
 the concatenation of lines from the commit message up to the first blank

builtin/log.c

@@ -699,6 +699,7 @@ static int do_signoff;
 static const char *signature = git_version_string;
 static const char *signature_file;
 static int config_cover_letter;
+static const char *config_output_directory;
 
 enum {
 	COVER_UNSET,
@@ -777,6 +778,8 @@ static int git_format_config(const char *var, const char *value, void *cb)
 		config_cover_letter = git_config_bool(var, value) ? COVER_ON : COVER_OFF;
 		return 0;
 	}
+	if (!strcmp(var, "format.outputdirectory"))
+		return git_config_string(&config_output_directory, var, value);
 
 	return git_log_config(var, value, cb);
 }
@@ -1391,6 +1394,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (rev.show_notes)
 		init_display_notes(&rev.notes_opt);
 
+	if (!output_directory && !use_stdout)
+		output_directory = config_output_directory;
+
 	if (!use_stdout)
 		output_directory = set_outdir(prefix, output_directory);
 	else

t/t4014-format-patch.sh

@@ -1445,4 +1445,19 @@ test_expect_success 'From line has expected format' '
 	test_cmp from filtered
 '
 
+test_expect_success 'format-patch format.outputDirectory option' '
+	test_config format.outputDirectory patches &&
+	rm -fr patches &&
+	git format-patch master..side &&
+	test $(git rev-list master..side | wc -l) -eq $(ls patches | wc -l)
+'
+
+test_expect_success 'format-patch -o overrides format.outputDirectory' '
+	test_config format.outputDirectory patches &&
+	rm -fr patches patchset &&
+	git format-patch master..side -o patchset &&
+	test_path_is_missing patches &&
+	test_path_is_dir patchset
+'
+
 test_done