ignore unhandled meta key sequences and escape sequences, and indicate

it on the statusbar when we get an unhandled shortcut or toggle, as Pico
does


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@3554 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

@@ -96,6 +96,12 @@ CVS code -
 	  do_page_down(), do_up(), do_scroll_up(), do_down(),
 	  do_scroll_down(), do_input(), do_search(), do_research(), and
 	  do_delete(). (DLR)
+	- Ignore unhandled meta key sequences and escape sequences, and
+	  indicate it on the statusbar when we get an unhandled shortcut
+	  or toggle, as Pico does.  New function is_ascii_cntrl_char();
+	  changes to do_input(), do_statusbar_input(), and
+	  parse_kbinput(). (DLR, suggested by Nick Warne and Benno
+	  Schulenberg)
 - browser.c:
   do_browser()
 	- Reference NANO_GOTODIR_(ALT|F)?KEY instead of

src/chars.c

@@ -120,6 +120,13 @@ bool is_blank_mbchar(const char *c)
 	return isblank((unsigned char)*c);
 }
 
+/* This function is equivalent to iscntrl(), except in that it only
+ * handles non-high-bit control characters. */
+bool is_ascii_cntrl_char(int c)
+{
+    return (0 <= c && c < 32);
+}
+
 /* This function is equivalent to iscntrl(), except in that it also
  * handles high-bit control characters. */
 bool is_cntrl_char(int c)

src/nano.c

@@ -1297,6 +1297,17 @@ int do_input(bool *meta_key, bool *func_key, bool *s_or_t, bool
 #endif
 	);
 
+    /* If we got a non-high-bit control key or a Meta key sequence, and
+     * it's not a shortcut or toggle, ignore it, and indicate this on
+     * the statusbar. */
+    if (*s_or_t == FALSE) {
+	if (is_ascii_cntrl_char(input) || *meta_key == TRUE) {
+	    input = ERR;
+	    *meta_key = FALSE;
+	    statusbar(_("Unknown Command"));
+	}
+    }
+
     if (allow_funcs) {
 	/* If we got a character, and it isn't a shortcut or toggle,
 	 * it's a normal text character.  Display the warning if we're

src/prompt.c

@@ -99,6 +99,15 @@ int do_statusbar_input(bool *meta_key, bool *func_key, bool *s_or_t,
     /* Set s_or_t to TRUE if we got a shortcut. */
     *s_or_t = have_shortcut;
 
+    /* If we got a non-high-bit control key or a Meta key sequence, and
+     * it's not a shortcut or toggle, ignore it. */
+    if (*s_or_t == FALSE) {
+	if (is_ascii_cntrl_char(input) || *meta_key == TRUE) {
+	    input = ERR;
+	    *meta_key = FALSE;
+	}
+    }
+
     if (allow_funcs) {
 	/* If we got a character, and it isn't a shortcut or toggle,
 	 * it's a normal text character.  Display the warning if we're

src/proto.h

@@ -174,6 +174,7 @@ bool niswblank(wchar_t wc);
 bool is_byte(int c);
 bool is_alnum_mbchar(const char *c);
 bool is_blank_mbchar(const char *c);
+bool is_ascii_cntrl_char(int c);
 bool is_cntrl_char(int c);
 #ifdef ENABLE_UTF8
 bool is_cntrl_wchar(wchar_t wc);

src/winio.c

@@ -536,10 +536,10 @@ int parse_kbinput(WINDOW *win, bool *meta_key, bool *func_key)
 				&ignore_seq);
 
 			/* If the escape sequence is unrecognized and
-			 * not ignored, put back all of its characters
-			 * except for the initial escape. */
+			 * not ignored, indicate this on the
+			 * statusbar. */
 			if (retval == ERR && !ignore_seq)
-			    unget_input(seq, seq_len);
+			    statusbar(_("Unknown Command"));
 
 			free(seq);
 		    }