locking: when finding a lock file at startup, quit when user cancels

When at startup the user presses Cancel at the "open anyway?" prompt,
cancel the whole startup: quit.  But when the user answers No, just
skip the file and continue starting up.

src/files.c

@@ -335,6 +335,10 @@ int do_lockfile(const char *filename, bool ask_the_user)
 		choice = do_yesno_prompt(FALSE, promptstr);
 		free(promptstr);
 
+		/* When the user cancelled while we're still starting up, quit. */
+		if (choice < 0 && !we_are_running)
+			finish();
+
 		if (choice < 1) {
 			retval = -1;
 			wipe_statusbar();

src/global.c

@@ -59,6 +59,9 @@ bool started_curses = FALSE;
 bool suppress_cursorpos = FALSE;
 		/* Should we skip constant position display for current keystroke? */
 
+bool we_are_running = FALSE;
+		/* Will become TRUE as soon as all options and files have been read. */
+
 message_type lastmessage = HUSH;
 		/* Messages of type HUSH should not overwrite type MILD nor ALERT. */
 

src/nano.c

@@ -2573,6 +2573,8 @@ int main(int argc, char **argv)
 		statusbar(_("Welcome to nano.  For basic help, type Ctrl+G."));
 #endif
 
+	we_are_running = TRUE;
+
 	while (TRUE) {
 #ifdef ENABLE_LINENUMBERS
 		confirm_margin();

src/proto.h

@@ -43,6 +43,7 @@ extern bool control_C_was_pressed;
 extern bool suppress_cursorpos;
 
 extern bool started_curses;
+extern bool we_are_running;
 
 extern message_type lastmessage;