[PATCH v4 4/6] pager: introduce setup_custom_pager

["Rubén Justo" <rjusto@gmail.com>]

Introduce a new function setup_custom_pager() to allow setting up our
pager mechanism using a custom pager.  If the custom pager specified is
NULL or an empty string, use the normal pager as setup_pager() currently
does.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
---
 pager.c | 17 +++++++++++------
 pager.h |  6 +++++-
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/pager.c b/pager.c
index 925f860335..21a7d9cd60 100644
--- a/pager.c
+++ b/pager.c
@@ -74,14 +74,13 @@ static int core_pager_config(const char *var, const char *value,
 	return 0;
 }
 
-const char *git_pager(int stdout_is_tty)
+static const char *git_pager_custom(int stdout_is_tty, const char* pager)
 {
-	const char *pager;
-
 	if (!stdout_is_tty)
 		return NULL;
 
-	pager = getenv("GIT_PAGER");
+	if (!pager || !*pager)
+		pager = getenv("GIT_PAGER");
 	if (!pager) {
 		if (!pager_program)
 			read_early_config(core_pager_config, NULL);
@@ -97,6 +96,11 @@ const char *git_pager(int stdout_is_tty)
 	return pager;
 }
 
+const char *git_pager(int stdout_is_tty)
+{
+	return git_pager_custom(stdout_is_tty, NULL);
+}
+
 static void setup_pager_env(struct strvec *env)
 {
 	const char **argv;
@@ -132,10 +136,11 @@ void prepare_pager_args(struct child_process *pager_process, const char *pager)
 	pager_process->trace2_child_class = "pager";
 }
 
-void setup_pager(void)
+void setup_custom_pager(const char* pager)
 {
 	static int once = 0;
-	const char *pager = git_pager(isatty(1));
+
+	pager = git_pager_custom(isatty(1), pager);
 
 	if (!pager)
 		return;
diff --git a/pager.h b/pager.h
index 103ecac476..2166662361 100644
--- a/pager.h
+++ b/pager.h
@@ -4,7 +4,11 @@
 struct child_process;
 
 const char *git_pager(int stdout_is_tty);
-void setup_pager(void);
+void setup_custom_pager(const char*);
+static inline void setup_pager(void)
+{
+	setup_custom_pager(NULL);
+}
 void wait_for_pager(void);
 int pager_in_use(void);
 int term_columns(void);
-- 
2.45.0.97.gb691764a17