branch: respect `pager.branch` in list-mode only

Similar to de121ffe5 (tag: respect `pager.tag` in list-mode only,
2017-08-02), use the DELAY_PAGER_CONFIG-mechanism to only respect
`pager.branch` when we are listing branches.

We have two possibilities of generalizing what that earlier commit made
to `git tag`. One is to interpret, e.g., --set-upstream-to as "it does
not use an editor, so we should page". Another, the one taken by this
commit, is to say "it does not list, so let's not page". That is in line
with the approach of the series on `pager.tag` and in particular the
wording in Documentation/git-tag.txt, which this commit reuses for
git-branch.txt.

This fixes the failing test added in the previous commit. Also adapt the
test for whether `git branch --set-upstream-to` respects `pager.branch`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -271,6 +271,12 @@ start-point is either a local or remote-tracking branch.
 	pointed at by a ref being shown.  The format is the same as
 	that of linkgit:git-for-each-ref[1].
 
+CONFIGURATION
+-------------
+`pager.branch` is only respected when listing branches, i.e., when
+`--list` is used or implied.
+See linkgit:git-config[1].
+
 Examples
 --------
 

builtin/branch.c

@@ -648,6 +648,9 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		rename *= 2;
 	}
 
+	if (list)
+		setup_auto_pager("branch", 0);
+
 	if (delete) {
 		if (!argc)
 			die(_("branch name required"));

git.c

@@ -368,7 +368,7 @@ static struct cmd_struct commands[] = {
 	{ "archive", cmd_archive, RUN_SETUP_GENTLY },
 	{ "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 	{ "blame", cmd_blame, RUN_SETUP },
-	{ "branch", cmd_branch, RUN_SETUP },
+	{ "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 	{ "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 	{ "cat-file", cmd_cat_file, RUN_SETUP },
 	{ "check-attr", cmd_check_attr, RUN_SETUP },

t/t7006-pager.sh

@@ -232,7 +232,7 @@ test_expect_success TTY 'git branch respects --no-pager' '
 	! test -e paginated.out
 '
 
-test_expect_failure TTY 'git branch --edit-description ignores pager.branch' '
+test_expect_success TTY 'git branch --edit-description ignores pager.branch' '
 	rm -f paginated.out editor.used &&
 	write_script editor <<-\EOF &&
 		echo "New description" >"$1"
@@ -243,13 +243,13 @@ test_expect_failure TTY 'git branch --edit-description ignores pager.branch' '
 	test -e editor.used
 '
 
-test_expect_success TTY 'git branch --set-upstream-to respects pager.branch' '
+test_expect_success TTY 'git branch --set-upstream-to ignores pager.branch' '
 	rm -f paginated.out &&
 	git branch other &&
 	test_when_finished "git branch -D other" &&
 	test_terminal git -c pager.branch branch --set-upstream-to=other &&
 	test_when_finished "git branch --unset-upstream" &&
-	test -e paginated.out
+	! test -e paginated.out
 '
 
 # A colored commit log will begin with an appropriate ANSI escape