Merge branch 'cm/save-restore-terminal'

An editor session launched during a Git operation (e.g. during 'git
commit') can leave the terminal in a funny state.  The code path
has updated to save the terminal state before, and restore it
after, it spawns an editor.

* cm/save-restore-terminal:
  editor: save and reset terminal after calling EDITOR
  terminal: teach git how to save/restore its terminal settings

2 files changed, 63 insertions, 15 deletions

diff --git a/compat/terminal.c b/compat/terminal.c
index 43b73dd..5b903e7 100644
--- a/compat/terminal.c
+++ b/compat/terminal.c
@@ -8,8 +8,6 @@
 
 #if defined(HAVE_DEV_TTY) || defined(GIT_WINDOWS_NATIVE)
 
-static void restore_term(void);
-
 static void restore_term_on_signal(int sig)
 {
 	restore_term();
@@ -25,7 +23,7 @@ static void restore_term_on_signal(int sig)
 static int term_fd = -1;
 static struct termios old_term;
 
-static void restore_term(void)
+void restore_term(void)
 {
 	if (term_fd < 0)
 		return;
@@ -35,15 +33,22 @@ static void restore_term(void)
 	term_fd = -1;
 }
 
+int save_term(int full_duplex)
+{
+	if (term_fd < 0)
+		term_fd = open("/dev/tty", O_RDWR);
+
+	return (term_fd < 0) ? -1 : tcgetattr(term_fd, &old_term);
+}
+
 static int disable_bits(tcflag_t bits)
 {
 	struct termios t;
 
-	term_fd = open("/dev/tty", O_RDWR);
-	if (tcgetattr(term_fd, &t) < 0)
+	if (save_term(0) < 0)
 		goto error;
 
-	old_term = t;
+	t = old_term;
 	sigchain_push_common(restore_term_on_signal);
 
 	t.c_lflag &= ~bits;
@@ -75,9 +80,10 @@ static int enable_non_canonical(void)
 static int use_stty = 1;
 static struct string_list stty_restore = STRING_LIST_INIT_DUP;
 static HANDLE hconin = INVALID_HANDLE_VALUE;
-static DWORD cmode;
+static HANDLE hconout = INVALID_HANDLE_VALUE;
+static DWORD cmode_in, cmode_out;
 
-static void restore_term(void)
+void restore_term(void)
 {
 	if (use_stty) {
 		int i;
@@ -97,9 +103,42 @@ static void restore_term(void)
 	if (hconin == INVALID_HANDLE_VALUE)
 		return;
 
-	SetConsoleMode(hconin, cmode);
+	SetConsoleMode(hconin, cmode_in);
+	CloseHandle(hconin);
+	if (cmode_out) {
+		assert(hconout != INVALID_HANDLE_VALUE);
+		SetConsoleMode(hconout, cmode_out);
+		CloseHandle(hconout);
+	}
+
+	hconin = hconout = INVALID_HANDLE_VALUE;
+}
+
+int save_term(int full_duplex)
+{
+	hconin = CreateFileA("CONIN$", GENERIC_READ | GENERIC_WRITE,
+	    FILE_SHARE_READ, NULL, OPEN_EXISTING,
+	    FILE_ATTRIBUTE_NORMAL, NULL);
+	if (hconin == INVALID_HANDLE_VALUE)
+		return -1;
+
+	if (full_duplex) {
+		hconout = CreateFileA("CONOUT$", GENERIC_READ | GENERIC_WRITE,
+			FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
+			FILE_ATTRIBUTE_NORMAL, NULL);
+		if (hconout == INVALID_HANDLE_VALUE)
+			goto error;
+
+		GetConsoleMode(hconout, &cmode_out);
+	}
+
+	GetConsoleMode(hconin, &cmode_in);
+	use_stty = 0;
+	return 0;
+error:
 	CloseHandle(hconin);
 	hconin = INVALID_HANDLE_VALUE;
+	return -1;
 }
 
 static int disable_bits(DWORD bits)
@@ -135,15 +174,11 @@ static int disable_bits(DWORD bits)
 		use_stty = 0;
 	}
 
-	hconin = CreateFile("CONIN$", GENERIC_READ | GENERIC_WRITE,
-	    FILE_SHARE_READ, NULL, OPEN_EXISTING,
-	    FILE_ATTRIBUTE_NORMAL, NULL);
-	if (hconin == INVALID_HANDLE_VALUE)
+	if (save_term(0) < 0)
 		return -1;
 
-	GetConsoleMode(hconin, &cmode);
 	sigchain_push_common(restore_term_on_signal);
-	if (!SetConsoleMode(hconin, cmode & ~bits)) {
+	if (!SetConsoleMode(hconin, cmode_in & ~bits)) {
 		CloseHandle(hconin);
 		hconin = INVALID_HANDLE_VALUE;
 		return -1;
@@ -361,6 +396,16 @@ int read_key_without_echo(struct strbuf *buf)
 
 #else
 
+int save_term(int full_duplex)
+{
+	/* full_duplex == 1, but no support available */
+	return -full_duplex;
+}
+
+void restore_term(void)
+{
+}
+
 char *git_terminal_prompt(const char *prompt, int echo)
 {
 	return getpass(prompt);
diff --git a/compat/terminal.h b/compat/terminal.h
index a9d52b8..e1770c5 100644
--- a/compat/terminal.h
+++ b/compat/terminal.h
@@ -1,6 +1,9 @@
 #ifndef COMPAT_TERMINAL_H
 #define COMPAT_TERMINAL_H
 
+int save_term(int full_duplex);
+void restore_term(void);
+
 char *git_terminal_prompt(const char *prompt, int echo);
 
 /* Read a single keystroke, without echoing it to the terminal */