cli: Provide optional support for libedit instead of readline

The libreadline starting from version 6 is licensed as GPLv3. For some
use cases it is not acceptable to use this license.

In the NetworkManager the libreadline is used by nmcli.
This change allows using libedit instead of libreadline.

Following adjustments were made:
1. The history_set_history_state() is not supported in the libedit.
   Instead, the where_history() with remove_history() were used to remove
   the history content if needed.

2. rl_complete_with_tilde_expansion - it is the binary flag used only
   when one wants to have the expansion support. The libedit is not
   supporting and hence exporting this flag.

src/nmcli/agent.c

@@ -7,9 +7,12 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#if HAVE_EDITLINE_READLINE
+#include <editline/readline.h>
+#else
 #include <readline/readline.h>
 #include <readline/history.h>
-
+#endif
 #include "common.h"
 #include "utils.h"
 #include "libnmc-base/nm-secret-agent-simple.h"

src/nmcli/common.c

@@ -10,9 +10,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/ioctl.h>
-#include <readline/readline.h>
+#if HAVE_EDITLINE_READLINE
+#include <editline/readline.h>
+#else
 #include <readline/history.h>
-
+#include <readline/readline.h>
+#endif
 #include "libnm-client-aux-extern/nm-libnm-aux.h"
 
 #include "libnmc-base/nm-vpn-helpers.h"
@@ -1007,10 +1010,14 @@ nmc_readline_echo(const NmcConfig *nmc_config, gboolean echo_on, const char *pro
     va_list       args;
     gs_free char *prompt = NULL;
     char *        str;
+#if HAVE_READLINE_HISTORY
     nm_auto_free HISTORY_STATE *saved_history  = NULL;
     HISTORY_STATE               passwd_history = {
         0,
     };
+#else
+    int start, curpos;
+#endif
 
     va_start(args, prompt_fmt);
     prompt = g_strdup_vprintf(prompt_fmt, args);
@@ -1020,8 +1027,12 @@ nmc_readline_echo(const NmcConfig *nmc_config, gboolean echo_on, const char *pro
 
     /* Hide the actual password */
     if (!echo_on) {
+#if HAVE_READLINE_HISTORY
         saved_history = history_get_history_state();
         history_set_history_state(&passwd_history);
+#else
+        start  = where_history();
+#endif
         /* stifling history is important as it tells readline to
          * not store anything, otherwise sensitive data could be
          * leaked */
@@ -1034,7 +1045,13 @@ nmc_readline_echo(const NmcConfig *nmc_config, gboolean echo_on, const char *pro
     /* Restore the non-hiding behavior */
     if (!echo_on) {
         rl_redisplay_function = rl_redisplay;
+#if HAVE_READLINE_HISTORY
         history_set_history_state(saved_history);
+#else
+        curpos = where_history();
+        while (curpos > start)
+            remove_history(curpos--);
+#endif
     }
 
     return str;

src/nmcli/connections.c

@@ -11,8 +11,12 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <signal.h>
+#if HAVE_EDITLINE_READLINE
+#include <editline/readline.h>
+#else
 #include <readline/readline.h>
 #include <readline/history.h>
+#endif
 #include <fcntl.h>
 
 #include "libnm-glib-aux/nm-dbus-aux.h"
@@ -6453,8 +6457,10 @@ gen_property_values(const char *text, int state)
     return nmc_rl_gen_func_basic(text, state, avals);
 }
 
+#if !HAVE_EDITLINE_READLINE
 /* from readline */
 extern int rl_complete_with_tilde_expansion;
+#endif
 
 /*
  * Attempt to complete on the contents of TEXT.  START and END show the
@@ -6482,8 +6488,10 @@ nmcli_editor_tab_completion(const char *text, int start, int end)
     /* Disable default filename completion */
     rl_attempted_completion_over = 1;
 
+#if !HAVE_EDITLINE_READLINE
     /* Enable tilde expansion when filenames are completed */
     rl_complete_with_tilde_expansion = 1;
+#endif
 
     /* Filter out possible ANSI color escape sequences */
     prompt_tmp = nmc_filter_out_colors((const char *) rl_prompt);
@@ -9617,8 +9625,10 @@ nmcli_con_tab_completion(const char *text, int start, int end)
         nmc_tab_completion.words = _meta_abstract_complete(info, text);
         generator_func           = _meta_abstract_generator;
     } else if (nm_streq0(rl_prompt, PROMPT_IMPORT_FILE)) {
-        rl_attempted_completion_over     = 0;
+        rl_attempted_completion_over = 0;
+#if !HAVE_EDITLINE_READLINE
         rl_complete_with_tilde_expansion = 1;
+#endif
     } else if (nm_streq0(rl_prompt, PROMPT_VPN_CONNECTION)) {
         generator_func = gen_vpn_ids;
     }

src/nmcli/devices.c

@@ -9,7 +9,11 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#if HAVE_EDITLINE_READLINE
+#include <editline/readline.h>
+#else
 #include <readline/readline.h>
+#endif
 #include <linux/if_ether.h>
 
 #include "libnm-glib-aux/nm-secret-utils.h"

src/nmcli/nmcli.c

@@ -14,8 +14,12 @@
 #include <termios.h>
 #include <unistd.h>
 #include <locale.h>
+#if HAVE_EDITLINE_READLINE
+#include <editline/readline.h>
+#else
 #include <readline/readline.h>
 #include <readline/history.h>
+#endif
 
 #include "libnmc-base/nm-client-utils.h"