[PATCH v4 1/2] refactor "dumb" terminal determination

[lars.schneider@autodesk.com]

From: Lars Schneider <larsxschneider@gmail.com>

Move the code to detect "dumb" terminals into a single location. This
avoids duplicating the terminal detection code yet again in a subsequent
commit.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 cache.h    | 1 +
 color.c    | 3 +--
 editor.c   | 9 +++++++--
 sideband.c | 5 ++---
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/cache.h b/cache.h
index 89f5d24579..3842fc097c 100644
--- a/cache.h
+++ b/cache.h
@@ -1469,6 +1469,7 @@ extern const char *ident_default_name(void);
 extern const char *ident_default_email(void);
 extern const char *git_editor(void);
 extern const char *git_pager(int stdout_is_tty);
+extern int is_terminal_dumb(void);
 extern int git_ident_config(const char *, const char *, void *);
 extern void reset_ident_date(void);
 
diff --git a/color.c b/color.c
index 9a9261ac16..d48dd947c9 100644
--- a/color.c
+++ b/color.c
@@ -329,8 +329,7 @@ static int check_auto_color(void)
 	if (color_stdout_is_tty < 0)
 		color_stdout_is_tty = isatty(1);
 	if (color_stdout_is_tty || (pager_in_use() && pager_use_color)) {
-		char *term = getenv("TERM");
-		if (term && strcmp(term, "dumb"))
+		if (!is_terminal_dumb())
 			return 1;
 	}
 	return 0;
diff --git a/editor.c b/editor.c
index 7519edecdc..c65ea698eb 100644
--- a/editor.c
+++ b/editor.c
@@ -7,11 +7,16 @@
 #define DEFAULT_EDITOR "vi"
 #endif
 
+int is_terminal_dumb(void)
+{
+	const char *terminal = getenv("TERM");
+	return !terminal || !strcmp(terminal, "dumb");
+}
+
 const char *git_editor(void)
 {
 	const char *editor = getenv("GIT_EDITOR");
-	const char *terminal = getenv("TERM");
-	int terminal_is_dumb = !terminal || !strcmp(terminal, "dumb");
+	int terminal_is_dumb = is_terminal_dumb();
 
 	if (!editor && editor_program)
 		editor = editor_program;
diff --git a/sideband.c b/sideband.c
index 1e4d684d6c..6d7f943e43 100644
--- a/sideband.c
+++ b/sideband.c
@@ -20,13 +20,12 @@
 
 int recv_sideband(const char *me, int in_stream, int out)
 {
-	const char *term, *suffix;
+	const char *suffix;
 	char buf[LARGE_PACKET_MAX + 1];
 	struct strbuf outbuf = STRBUF_INIT;
 	int retval = 0;
 
-	term = getenv("TERM");
-	if (isatty(2) && term && strcmp(term, "dumb"))
+	if (isatty(2) && !is_terminal_dumb())
 		suffix = ANSI_SUFFIX;
 	else
 		suffix = DUMB_SUFFIX;
-- 
2.15.0