[PATCH] bindings: show either "^/" or "^-" in the help lines, instead of "^_"

[Benno Schulenberg]

The "^_" has always been poorly legible (the underscore melting into
the bottom of the terminal) and difficult to type (Shift+Ctrl+minus).
The "^/" is both more readable and easier to type.

In terminal emulators, "^/" is shown, but on a Linux console "^-",
as ^/ does a backspace in the default console key mapping.

Also, allow rebinding ^- in the nanorc files.

This addresses https://savannah.gnu.org/bugs/?57393.


[I thought I had sent this patch to the list at some point,
but I can't find it in the archives.]

---
 src/global.c           | 14 +++++++++++---
 syntax/nanohelp.nanorc |  2 +-
 syntax/nanorc.nanorc   |  4 ++--
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/global.c b/src/global.c
index cdef1686..1ca558f6 100644
--- a/src/global.c
+++ b/src/global.c
@@ -384,7 +384,7 @@ int keycode_from_string(const char *keystring)
 {
        if (keystring[0] == '^') {
                if (keystring[2] == '\0') {
-                       if (keystring[1] == '/')
+                       if (keystring[1] == '/' || keystring[1] == '-')
                                return 31;
                        if (keystring[1] <= '_')
                                return keystring[1] - 64;
@@ -1192,6 +1192,12 @@ void shortcut_init(void)
                N_("Next Linter message"), WITHORSANS(nextlint_gist), TOGETHER, 
VIEW);
 #endif
 
+#ifdef __linux__
+#define SLASH_OR_DASH  (on_a_vt) ? "^-" : "^/"
+#else
+#define SLASH_OR_DASH  "^/"
+#endif
+
        /* Link key combos to functions in certain menus. */
        add_to_sclist(MMOST|MBROWSER, "^M", '\r', do_enter, 0);
        add_to_sclist(MMOST|MBROWSER, "Enter", KEY_ENTER, do_enter, 0);
@@ -1233,8 +1239,9 @@ void shortcut_init(void)
        add_to_sclist(MEXECUTE, "^O", 0, do_formatter, 0);
 #endif
        add_to_sclist(MMAIN, "^C", 0, report_cursor_position, 0);
-       add_to_sclist(MMAIN, "^_", 0, do_gotolinecolumn_void, 0);
+       add_to_sclist(MMAIN, SLASH_OR_DASH, 0, do_gotolinecolumn_void, 0);
        add_to_sclist(MMAIN, "M-G", 0, do_gotolinecolumn_void, 0);
+       add_to_sclist(MMAIN, "^_", 0, do_gotolinecolumn_void, 0);
        add_to_sclist(MMAIN|MBROWSER|MHELP|MLINTER, "^Y", 0, do_page_up, 0);
        add_to_sclist(MMAIN|MBROWSER|MHELP|MLINTER, "PgUp", KEY_PPAGE, 
do_page_up, 0);
        add_to_sclist(MMAIN|MBROWSER|MHELP|MLINTER, "^V", 0, do_page_down, 0);
@@ -1455,8 +1462,9 @@ void shortcut_init(void)
        add_to_sclist(MBROWSER, "End", KEY_END, to_last_file, 0);
        add_to_sclist(MBROWSER, "^Home", CONTROL_HOME, to_first_file, 0);
        add_to_sclist(MBROWSER, "^End", CONTROL_END, to_last_file, 0);
-       add_to_sclist(MBROWSER, "^_", 0, goto_dir, 0);
+       add_to_sclist(MBROWSER, SLASH_OR_DASH, 0, goto_dir, 0);
        add_to_sclist(MBROWSER, "M-G", 0, goto_dir, 0);
+       add_to_sclist(MBROWSER, "^_", 0, goto_dir, 0);
 #endif
        if (ISSET(SAVE_ON_EXIT) && !ISSET(PRESERVE))
                add_to_sclist(MWRITEFILE, "^Q", 0, discard_buffer, 0);
diff --git a/syntax/nanohelp.nanorc b/syntax/nanohelp.nanorc
index 4295ba79..79c4b944 100644
--- a/syntax/nanohelp.nanorc
+++ b/syntax/nanohelp.nanorc
@@ -4,7 +4,7 @@
 syntax nanohelp
 
 # Key combos:
-color cyan "\^[]/4-8@A-Z\^_`◀▶▲▼]"  "[◀▶▲▼]"  "\<(M|S[Hh]-[Mm])-."  
"\<F([1-9]|1[0-9]|2[0-4])"
+color cyan "\^[]/4-8@A-Z\^_`◀▶▲▼-]"  "[◀▶▲▼]"  "\<(M|S[Hh]-[Mm])-."  
"\<F([1-9]|1[0-9]|2[0-4])"
 color cyan 
"\<((Sh-)?Tab|Enter|Ins|(Sh-\^?)?Del|Space|Bsp|Up|Down|Left|Right|Home|End|PgUp|PgDn)\>"
 
 # Quoted indicators:
diff --git a/syntax/nanorc.nanorc b/syntax/nanorc.nanorc
index c1209897..2cce6a9c 100644
--- a/syntax/nanorc.nanorc
+++ b/syntax/nanorc.nanorc
@@ -11,8 +11,8 @@ color brightgreen 
"^[[:blank:]]*(set|unset)[[:blank:]]+(afterends|allow_insecure
 color yellow 
"^[[:blank:]]*set[[:blank:]]+((error|function|key|number|prompt|scroller|selected|spotlight|status|stripe|title)color)[[:blank:]]+(bold,)?(italic,)?(bright|light)?(white|black|red|blue|green|yellow|magenta|cyan|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte)?(,(light)?(white|black|red|blue|green|yellow|magenta|cyan|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte))?\>"
 color brightgreen 
"^[[:blank:]]*set[[:blank:]]+(backupdir|brackets|errorcolor|functioncolor|keycolor|matchbrackets|numbercolor|operatingdir|promptcolor|punct|quotestr|scrollercolor|selectedcolor|speller|spotlightcolor|statuscolor|stripecolor|titlecolor|whitespace|wordchars)[[:blank:]]+"
 color brightgreen 
"^[[:blank:]]*set[[:blank:]]+(fill[[:blank:]]+-?[[:digit:]]+|(guidestripe|tabsize)[[:blank:]]+[1-9][0-9]*)\>"
-color brightgreen 
"^[[:blank:]]*bind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+([a-z]+|".*")[[:blank:]]+(main|help|search|replace(with)?|yesno|gotoline|writeout|insert|browser|whereisfile|gotodir|execute|spell|linter|all)([[:blank:]]+#|[[:blank:]]*$)"
-color brightgreen 
"^[[:blank:]]*unbind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+(all|main|search|replace(with)?|yesno|gotoline|writeout|insert|ext(ernal)?cmd|help|spell|linter|browser|whereisfile|gotodir)([[:blank:]]+#|[[:blank:]]*$)"
+color brightgreen 
"^[[:blank:]]*bind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`-]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+([a-z]+|".*")[[:blank:]]+(main|help|search|replace(with)?|yesno|gotoline|writeout|insert|browser|whereisfile|gotodir|execute|spell|linter|all)([[:blank:]]+#|[[:blank:]]*$)"
+color brightgreen 
"^[[:blank:]]*unbind[[:blank:]]+((\^([A-Za-z]|[]/@\^_`-]|Space)|([Ss][Hh]-)?[Mm]-[A-Za-z]|[Mm]-([][!"#$%&'()*+,./0-9:;<=>?@\^_`{|}~-]|Space))|F([1-9]|1[0-9]|2[0-4])|Ins|Del)[[:blank:]]+(all|main|search|replace(with)?|yesno|gotoline|writeout|insert|ext(ernal)?cmd|help|spell|linter|browser|whereisfile|gotodir)([[:blank:]]+#|[[:blank:]]*$)"
 color brightgreen 
"^[[:blank:]]*extendsyntax[[:blank:]]+[[:alpha:]]+[[:blank:]]+(i?color|header|magic|comment|formatter|linter|tabgives)[[:blank:]]+.*"
 color brightgreen 
"^[[:blank:]]*(syntax[[:blank:]]+[^[:space:]]+|(formatter|linter)[[:blank:]]+.+)"
 color green 
"^[[:blank:]]*((un)?(bind|set)|include|syntax|header|magic|comment|formatter|linter|tabgives|extendsyntax)\>"
-- 
2.29.3