input: neutralize two spurious keycodes from VTE terminals

At least some of the VTE-based terminals claim to be compatible with
xterm-25color (and set TERM to that value).  But they really aren't:
they mishandle the focus-in and focus-out events, for example.  So,
catch and discard the corresponding keycodes that nano shouldn't be
seeing at all.

This improves the fix for https://savannah.gnu.org/bugs/?64578.

doc/faq.html

@@ -222,10 +222,10 @@
 <blockquote><p>Try holding down the Shift key and selecting or pasting the text as you normally would.</p></blockquote>
 <h3><a name="4.6"></a>4.6. When I paste text into a document, each line gets indented further than the last. Why? And how can I stop this?</h3>
 <blockquote><p>You have the <i>autoindent</i> feature turned on. Hit <b>Meta-I</b> to turn it off, paste your text, and then hit <b>Meta-I</b> again to turn it back on.</p>
-  <p><i>Update:</i> Since version 4.8, nano will suppress auto-indentation during a paste, so you no longer need to toggle it off and on manually.</p></blockquote>
+  <p><i>Update:</i> Since version 4.8, nano will suppress auto-indentation during a paste (when your terminal understands <a href="https://en.wikipedia.org/wiki/Bracketed-paste">bracketed pastes</a>), so you no longer need to toggle it off and on manually.</p></blockquote>
 <h3><a name="4.7"></a>4.7. When I paste from Windows into a remote nano, nano rewraps the lines. What gives?</h3>
 <blockquote><p>When pasting from Windows, in some situations linefeeds are sent instead of carriage returns (Enters). And linefeeds are <b>^J</b>s, which make nano justify (rewrap) the current paragraph. To prevent these linefeeds from causing these unwanted justifications, add this line to your .nanorc on the remote Linux box: <b>unbind ^J main</b> or <b>bind ^J enter main</b>, depending on whether the paste contains CR + LF or only LF.</p>
-  <p><i>Update:</i> Since version 4.8, nano will ignore linefeed characters in a paste, so you no longer need the above workaround.</p></blockquote>
+  <p><i>Update:</i> Since version 4.8, nano will ignore linefeed characters in a paste (when your terminal understands <a href="https://en.wikipedia.org/wiki/Bracketed-paste">bracketed pastes</a>), so you no longer need the above workaround.</p></blockquote>
 <h3><a name="4.8"></a>4.8. I've compiled nano with color support, but I don't see any color when I run it!</h3>
 <blockquote><p>If you want nano to actually use color, you have to specify the color configurations you want it to use in your .nanorc. Several example configurations are in the <b>syntax/</b> subdirectory of the nano source, which are normally installed to <b>/usr/local/share/nano/</b>. To enable all of them, uncomment the line <b># include "/usr/local/share/nano/*.nanorc"</b> in your nanorc. See also section <a href="#3.9">3.9</a>.</p></blockquote>
 <h3><a name="4.9"></a>4.9. How do I make nano my default editor (in Pine, mutt, etc.)?</h3>

doc/nano.1

@@ -19,7 +19,7 @@
 .TH NANO 1 "version 7.2" "January 2023"
 
 .SH NAME
-nano \- Nano's ANOther editor, inspired by Pico
+nano \- Nano's ANOther text editor, inspired by Pico
 
 .SH SYNOPSIS
 .B nano
@@ -28,10 +28,10 @@ nano \- Nano's ANOther editor, inspired by Pico
 .B nano
 .RI [ options "] [" file [\fB: line [\fB: column "]]]..."
 .sp
-.BR nano " [" \fIoptions "] [[" + [ crCR ]( / | ? ) \fIstring "] " \fIfile ]...
+.BR nano " [" \fIoptions "] [[" + [ crCR ]{ / | ? } \fIstring "] " \fIfile ]...
 
 .SH DESCRIPTION
-\fBnano\fP is a small and friendly editor.  It copies the look and feel
+\fBnano\fP is a small and friendly text editor.  It copies the look and feel
 of Pico, but is free software, and implements several features that Pico
 lacks, such as: opening multiple files, scrolling per line, undo/redo,
 syntax coloring, line numbering, and soft-wrapping overlong lines.

doc/nano.texi

@@ -35,7 +35,7 @@ The complete manual for the GNU nano text editor.
 
 @page
 
-This manual documents the GNU @command{nano} editor.
+This manual documents the GNU @command{nano} text editor.
 @sp 1
 The contents of this manual are part of the GNU @command{nano} distribution.
 
@@ -163,7 +163,7 @@ A more complete command synopsis thus is:
 
 @blankline
 @example
-@code{nano [OPTION]@dots{} [[+LINE[,COLUMN]|+[crCR](/|?)STRING] FILE]@dots{}}
+@code{nano [OPTION]@dots{} [[+LINE[,COLUMN]|+[crCR]@{/|?@}STRING] FILE]@dots{}}
 @end example
 @blankline
 

doc/nanorc.5

@@ -23,7 +23,7 @@ nanorc \- GNU nano's configuration file
 
 .SH DESCRIPTION
 The \fInanorc\fP files contain the default settings for \fBnano\fP,
-a small and friendly editor.  During startup, if \fB\-\-rcfile\fR
+a small and friendly text editor.  During startup, if \fB\-\-rcfile\fR
 is not given, \fBnano\fR will read two files: first the
 system-wide settings, from \fI/etc/nanorc\fP (the exact path might be
 different on your system), and then the user-specific settings, either

doc/rnano.1

@@ -32,15 +32,19 @@ access to the filesystem nor to a command shell.
 .sp
 In restricted mode, \fBnano\fR will:
 .IP \[bu] 2
+not make backups;
+.IP \[bu]
 not allow suspending;
 .IP \[bu]
+not allow spell checking;
+.IP \[bu]
+not read nor write the history files;
+.IP \[bu]
 not allow saving the current buffer under a different name;
 .IP \[bu]
 not allow inserting another file or opening a new buffer;
 .IP \[bu]
-not allow appending or prepending to any file;
-.IP \[bu]
-not make backup files nor do spell checking.
+not allow appending or prepending to any file.
 
 .SH OPTIONS
 .TP

src/browser.c

@@ -436,7 +436,10 @@ char *browse(char *path)
 
 	titlebar(path);
 
-	while (TRUE) {
+	if (list_length == 0) {
+		statusline(ALERT, _("No entries"));
+		napms(1200);
+	} else while (TRUE) {
 		functionptrtype function;
 		int kbinput;
 

src/definitions.h

@@ -214,12 +214,15 @@
 #define SHIFT_DELETE    0x45D
 #define SHIFT_TAB       0x45F
 
+#define FOCUS_IN	0x491
+#define FOCUS_OUT	0x499
+
 /* Special keycodes for when a string bind has been partially implanted
  * or has an unpaired opening brace, or when a function in a string bind
  * needs execution or a specified function name is invalid. */
 #define MORE_PLANTS       0x4EA
 #define MISSING_BRACE     0x4EB
-#define PLANTED_COMMAND   0x4EC
+#define PLANTED_A_COMMAND 0x4EC
 #define NO_SUCH_FUNCTION  0x4EF
 
 /* A special keycode for when <Tab> is pressed while the mark is on. */

src/files.c

@@ -535,7 +535,8 @@ void mention_name_and_linecount(void)
 	if (ISSET(MINIBAR)) {
 		report_size = TRUE;
 		return;
-	}
+	} else if (ISSET(ZERO))
+		return;
 
 	if (openfile->fmt > NIX_FILE)
 		/* TRANSLATORS: First %s is file name, second %s is file format. */

src/global.c

@@ -107,6 +107,7 @@ int altpageup, altpagedown;
 int altinsert, altdelete;
 int shiftaltleft, shiftaltright, shiftaltup, shiftaltdown;
 #endif
+int mousefocusin, mousefocusout;
 
 #ifdef ENABLED_WRAPORJUSTIFY
 ssize_t fill = -COLUMNS_FROM_EOL;
@@ -266,9 +267,12 @@ char *startup_problem = NULL;
 #endif
 #ifdef ENABLE_NANORC
 char *custom_nanorc = NULL;
+		/* The argument of the --rcfile option, when given. */
 
 char *commandname = NULL;
+		/* The name (of a function) between braces in a string bind. */
 keystruct *planted_shortcut = NULL;
+		/* The function that the above name resolves to, if any. */
 #endif
 
 bool spotlighted = FALSE;
@@ -464,7 +468,7 @@ const keystruct *get_shortcut(const int keycode)
 		return NULL;
 #endif
 #ifdef ENABLE_NANORC
-	if (keycode == PLANTED_COMMAND)
+	if (keycode == PLANTED_A_COMMAND)
 		return planted_shortcut;
 #endif
 
@@ -978,7 +982,10 @@ void shortcut_init(void)
 	add_to_funcs(do_verbatim_input, MMAIN,
 			N_("Verbatim"), WHENHELP(verbatim_gist), BLANKAFTER);
 
-#ifndef NANO_TINY
+#ifdef NANO_TINY
+	add_to_funcs(do_search_backward, MMAIN,
+			N_("Where Was"), WHENHELP(wherewas_gist), BLANKAFTER);
+#else
 	add_to_funcs(do_indent, MMAIN,
 			N_("Indent"), WHENHELP(indent_gist), TOGETHER);
 	add_to_funcs(do_unindent, MMAIN,
@@ -1010,29 +1017,27 @@ void shortcut_init(void)
 	add_to_funcs(to_next_anchor, MMAIN,
 			N_("Down to anchor"), WHENHELP(nextanchor_gist), BLANKAFTER);
 
-	if (!ISSET(RESTRICTED)) {
 #ifdef ENABLE_SPELLER
-		add_to_funcs(do_spell, MMAIN,
-				N_("Spell Check"), WHENHELP(spell_gist), TOGETHER);
+	add_to_funcs(do_spell, MMAIN,
+			N_("Spell Check"), WHENHELP(spell_gist), TOGETHER);
 #endif
 #ifdef ENABLE_LINTER
-		add_to_funcs(do_linter, MMAIN,
-				N_("Linter"), WHENHELP(lint_gist), TOGETHER);
+	add_to_funcs(do_linter, MMAIN,
+			N_("Linter"), WHENHELP(lint_gist), TOGETHER);
 #endif
 #ifdef ENABLE_FORMATTER
-		add_to_funcs(do_formatter, MMAIN,
-				N_("Formatter"), WHENHELP(formatter_gist), BLANKAFTER);
+	add_to_funcs(do_formatter, MMAIN,
+			N_("Formatter"), WHENHELP(formatter_gist), BLANKAFTER);
 #endif
-	}
-#endif /* !NANO_TINY */
+	/* Although not allowed in restricted mode, keep execution rebindable. */
+	if (ISSET(RESTRICTED))
+		add_to_funcs(do_execute, MMAIN,
+				N_("Execute"), WHENHELP(execute_gist), TOGETHER);
 
-#ifdef NANO_TINY
-	add_to_funcs(do_search_backward, MMAIN,
-			N_("Where Was"), WHENHELP(wherewas_gist), BLANKAFTER);
-#else
 	add_to_funcs(do_suspend, MMAIN,
 			N_("Suspend"), WHENHELP(suspend_gist), TOGETHER);
-#endif
+#endif /* !NANO_TINY */
+
 #ifdef ENABLE_HELP
 	add_to_funcs(full_refresh, MMAIN,
 			N_("Refresh"), WHENHELP(refresh_gist), TOGETHER);
@@ -1103,16 +1108,15 @@ void shortcut_init(void)
 			N_("No Conversion"), WHENHELP(convert_gist), BLANKAFTER);
 
 	/* Command execution is only available when not in restricted mode. */
-	if (!ISSET(RESTRICTED) && !ISSET(VIEW_MODE)) {
+	if (!ISSET(RESTRICTED) && !ISSET(VIEW_MODE))
 		add_to_funcs(flip_execute, MINSERTFILE,
 				N_("Execute Command"), WHENHELP(execute_gist), BLANKAFTER);
 
-		add_to_funcs(cut_till_eof, MEXECUTE,
-				N_("Cut Till End"), WHENHELP(cuttilleof_gist), BLANKAFTER);
+	add_to_funcs(cut_till_eof, MEXECUTE,
+			N_("Cut Till End"), WHENHELP(cuttilleof_gist), BLANKAFTER);
 
-		add_to_funcs(do_suspend, MEXECUTE,
-				N_("Suspend"), WHENHELP(suspend_gist), BLANKAFTER);
-	}
+	add_to_funcs(do_suspend, MEXECUTE,
+			N_("Suspend"), WHENHELP(suspend_gist), BLANKAFTER);
 #endif /* !NANO_TINY */
 
 #ifdef ENABLE_BROWSER
@@ -1462,24 +1466,22 @@ void shortcut_init(void)
 #endif
 	}
 #endif
+	add_to_sclist(MBROWSER|MHELP, "^C", 0, do_exit, 0);
 #ifdef ENABLE_BROWSER
 	/* Only when not in restricted mode, allow entering the file browser. */
 	if (!ISSET(RESTRICTED))
 		add_to_sclist(MWRITEFILE|MINSERTFILE, "^T", 0, to_files, 0);
-#endif
-	add_to_sclist(MBROWSER|MHELP, "^C", 0, do_exit, 0);
-	/* Allow exiting from the file browser and the help viewer with
-	 * the same key as they were entered. */
-#ifdef ENABLE_BROWSER
+	/* Allow exiting the file browser with the same key as used for entry. */
 	add_to_sclist(MBROWSER, "^T", 0, do_exit, 0);
 #endif
 #ifdef ENABLE_HELP
+	/* Allow exiting the help viewer with the same keys as used for entry. */
 	add_to_sclist(MHELP, "^G", 0, do_exit, 0);
 	add_to_sclist(MHELP, "F1", KEY_F(1), do_exit, 0);
 	add_to_sclist(MHELP, "Home", KEY_HOME, to_first_line, 0);
 	add_to_sclist(MHELP, "End", KEY_END, to_last_line, 0);
 #endif
-#ifdef ENABLE_COLOR
+#ifdef ENABLE_LINTER
 	add_to_sclist(MLINTER, "^X", 0, do_cancel, 0);
 #endif
 	add_to_sclist(MMOST & ~MFINDINHELP, "F1", KEY_F(1), do_help, 0);

src/nano.c

@@ -2426,6 +2426,8 @@ int main(int argc, char **argv)
 	shiftaltup = get_keycode("kUP4", SHIFT_ALT_UP);
 	shiftaltdown = get_keycode("kDN4", SHIFT_ALT_DOWN);
 #endif
+	mousefocusin = get_keycode("kxIN", FOCUS_IN);
+	mousefocusout = get_keycode("kxOUT", FOCUS_OUT);
 
 #ifdef HAVE_SET_ESCDELAY
 	/* Tell ncurses to pass the Esc key quickly. */

src/prototypes.h

@@ -80,6 +80,7 @@ extern int altinsert, altdelete;
 extern int shiftaltleft, shiftaltright;
 extern int shiftaltup, shiftaltdown;
 #endif
+extern int mousefocusin, mousefocusout;
 
 #ifdef ENABLED_WRAPORJUSTIFY
 extern ssize_t fill;

src/rcfile.c

@@ -991,16 +991,22 @@ void parse_includes(char *ptr)
 }
 
 /* Return the index of the color that is closest to the given RGB levels,
- * assuming that the terminal uses the 6x6x6 color cube of xterm-256color. */
+ * assuming that the terminal uses the 6x6x6 color cube of xterm-256color.
+ * When red == green == blue, return an index in the xterm gray scale. */
 short closest_index_color(short red, short green, short blue)
 {
-	/* Translation table, from 16 intended levels to 6 available levels. */
+	/* Translation table, from 16 intended color levels to 6 available levels. */
 	static const short level[] = { 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5 };
 
-	if (COLORS == 256)
-		return (36 * level[red] + 6 * level[green] + level[blue] + 16);
-	else
+	/* Translation table, from 14 intended gray levels to 24 available levels. */
+	static const short gray[] = { 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 18, 21, 23 };
+
+	if (COLORS != 256)
 		return THE_DEFAULT;
+	else if (red == green && green == blue && 0 < red && red < 0xF)
+		return 232 + gray[red - 1];
+	else
+		return (36 * level[red] + 6 * level[green] + level[blue] + 16);
 }
 
 #define COLORCOUNT  34

src/winio.c

@@ -380,7 +380,7 @@ int get_code_from_plantation(void)
 		if (*plants_pointer != '\0')
 			put_back(MORE_PLANTS);
 
-		return PLANTED_COMMAND;
+		return PLANTED_A_COMMAND;
 	} else {
 		char *opening = strchr(plants_pointer, '{');
 		char firstbyte = *plants_pointer;
@@ -1245,6 +1245,10 @@ int parse_kbinput(WINDOW *frame)
 		return INDENT_KEY;
 #endif
 
+	/* Spurious codes from VTE -- see https://sv.gnu.org/bugs/?64578. */
+	if (keycode == mousefocusin || keycode == mousefocusout)
+		return ERR;
+
 	switch (keycode) {
 		case KEY_SLEFT:
 			shift_held = TRUE;