RFC [PATCH] possible new feature: exit with an error status of 2 for ^X^Q and for ^O^Q

Normally, nano exits with a status of 0.  But if the user wants to
make nano exit with an error status (to signal failure to a calling
program), they can now use ^X^Q (when the buffer is modified), or
^O^Q (when option --saveonexit is in effect).

This fulfills https://savannah.gnu.org/bugs/?65755.
Requested-by: Frank Wolff
---
 src/files.c      | 1 +
 src/global.c     | 3 +++
 src/nano.c       | 3 ++-
 src/prompt.c     | 6 ++++--
 src/prototypes.h | 2 ++
 5 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/files.c b/src/files.c
index fef47b27..c41340f3 100644
--- a/src/files.c
+++ b/src/files.c
@@ -2189,6 +2189,7 @@ int write_it_out(bool exiting, bool withprompt)
 
 		/* Upon request, abandon the buffer. */
 		if (function == discard_buffer) {
+			final_status = 2;  /* ^O^Q makes nano exit with an error. */
 			free(given);
 			return 2;
 		}
diff --git a/src/global.c b/src/global.c
index 9c6b1e66..38afb6a8 100644
--- a/src/global.c
+++ b/src/global.c
@@ -55,6 +55,9 @@ bool report_size = TRUE;
 bool ran_a_tool = FALSE;
 		/* Whether a tool has been run at the Execute-Command prompt. */
 
+int final_status = 0;
+		/* The status value that nano returns upon exit. */
+
 bool inhelp = FALSE;
 		/* Whether we are in the help viewer. */
 char *title = NULL;
diff --git a/src/nano.c b/src/nano.c
index 123af18d..6640754a 100644
--- a/src/nano.c
+++ b/src/nano.c
@@ -260,7 +260,7 @@ void finish(void)
 #endif
 
 	/* Get out. */
-	exit(0);
+	exit(final_status);
 }
 
 /* Close the current buffer, and terminate nano if it is the only buffer. */
@@ -2652,6 +2652,7 @@ int main(int argc, char **argv)
 			wredrawln(midwin, editwinrows - 1, 1);
 #endif
 
+		final_status = 0;
 		errno = 0;
 		focusing = TRUE;
 
diff --git a/src/prompt.c b/src/prompt.c
index d427d1ea..09571dd2 100644
--- a/src/prompt.c
+++ b/src/prompt.c
@@ -759,10 +759,12 @@ int ask_user(bool withall, const char *question)
 #endif
 		/* Interpret ^N as "No", to allow exiting in anger, and ^Q or ^X too. */
 		else if (kbinput == '\x0E' || (kbinput == '\x11' && !ISSET(MODERN_BINDINGS)) ||
-									  (kbinput == '\x18' && ISSET(MODERN_BINDINGS)))
+									  (kbinput == '\x18' && ISSET(MODERN_BINDINGS))) {
 			choice = NO;
+			if (kbinput != '\x0E')  /* ^X^Q makes nano exit with an error. */
+				final_status = 2;
 		/* And interpret ^Y as "Yes". */
-		else if (kbinput == '\x19')
+		} else if (kbinput == '\x19')
 			choice = YES;
 #ifdef ENABLE_MOUSE
 		else if (kbinput == KEY_MOUSE) {
diff --git a/src/prototypes.h b/src/prototypes.h
index 55ab21c1..b6acbde7 100644
--- a/src/prototypes.h
+++ b/src/prototypes.h
@@ -39,6 +39,8 @@ extern bool more_than_one;
 extern bool report_size;
 extern bool ran_a_tool;
 
+extern int final_status;
+
 extern bool inhelp;
 extern char *title;
 
-- 
2.42.1