tweaks: reshuffle some code to the one place that needs it

The extra things that close_buffer() did are only needed and useful
when manually closing a buffer, so move them there.  The other three
calls of close_buffer() only need to get rid of the current buffer
(making the preceding buffer the new current one) and nothing else.

src/files.c

@@ -462,7 +462,8 @@ bool open_buffer(const char *filename, bool new_buffer)
 				/* When not overriding an existing lock, discard the buffer. */
 				if (do_lockfile(realname) < 0) {
 #ifdef ENABLE_MULTIBUFFER
-					close_buffer();
+					openfile = openfile->prev;
+					close_buffer(openfile->next);
 #endif
 					free(realname);
 					return FALSE;
@@ -647,24 +648,12 @@ void switch_to_next_buffer(void)
 	switch_to_adjacent_buffer(FORWARD);
 }
 
-/* Delete the current entry from the circular list of open files,
- * after switching to the buffer after it. */
-void close_buffer(void)
+/* Remove the given buffer from the circular list of buffers. */
+void close_buffer(openfilestruct *buffer)
 {
-#ifdef ENABLE_HISTORIES
-	if (ISSET(POSITIONLOG) && !inhelp)
-		update_poshistory(openfile->filename,
-						openfile->current->lineno, xplustabs() + 1);
-#endif
+	unlink_opennode(buffer);
 
-	switch_to_next_buffer();
-
-	/* Delete the old file buffer, and adjust the count in the top bar. */
-	unlink_opennode(openfile->prev);
-	if (!inhelp)
-		titlebar(NULL);
-
-	/* If now just one buffer remains open, show "Exit" in the help lines. */
+	/* When just one buffer remains open, show "Exit" in the help lines. */
 	if (openfile == openfile->next)
 		exitfunc->desc = exit_tag;
 }

src/help.c

@@ -223,9 +223,9 @@ void do_help(void)
 		}
 	}
 
-	close_buffer();
-	/* Switch back to the buffer we were invoked from. */
+	/* Switch back to the original buffer and discard the help-text buffer. */
 	openfile = openfile->prev;
+	close_buffer(openfile->next);
 
 	/* Restore the settings of all flags. */
 	memcpy(flags, stash, sizeof(flags));
@@ -254,6 +254,8 @@ void do_help(void)
 	} else
 		bottombars(oldmenu);
 
+	prepare_for_display();
+
 #ifdef ENABLE_BROWSER
 	if (oldmenu == MBROWSER || oldmenu == MWHEREISFILE || oldmenu == MGOTODIR)
 		browser_refresh();

src/nano.c

@@ -1037,9 +1037,17 @@ void close_and_go(void)
 #endif
 #ifdef ENABLE_MULTIBUFFER
 	/* If there is another buffer, close this one; otherwise terminate. */
-	if (openfile != openfile->next)
-		close_buffer();
-	else
+	if (openfile != openfile->next) {
+#ifdef ENABLE_HISTORIES
+		if (ISSET(POSITIONLOG))
+			update_poshistory(openfile->filename,
+							openfile->current->lineno, xplustabs() + 1);
+#endif
+		switch_to_next_buffer();
+		close_buffer(openfile->prev);
+		/* Adjust the count in the top bar. */
+		titlebar(NULL);
+	} else
 #endif
 		finish();
 }

src/proto.h

@@ -276,7 +276,7 @@ void prepare_for_display(void);
 void mention_name_and_linecount(void);
 void switch_to_prev_buffer(void);
 void switch_to_next_buffer(void);
-void close_buffer(void);
+void close_buffer(openfilestruct *buffer);
 #endif
 void read_file(FILE *f, int fd, const char *filename, bool undoable);
 int open_file(const char *filename, bool newfie, FILE **f);

src/winio.c

@@ -3374,8 +3374,8 @@ void total_refresh(void)
 		titlebar(title);
 #ifdef ENABLE_HELP
 	if (inhelp) {
-		close_buffer();
 		openfile = openfile->prev;
+		close_buffer(openfile->next);
 		wrap_help_text_into_buffer();
 	} else
 #endif