From 110183e258519aa31f731db25a392d6a05c0f90c Mon Sep 17 00:00:00 2001
From: Paul Koning <ni1d@arrl.net>
Date: Wed, 28 Sep 2022 09:59:00 -0400
Subject: [PATCH] simh ui: replace "readline" by "editline".

This avoids infecting SIMH with the GPL license, since readline,
very surprisingly, is GPL rather than LGPL.

The replacement package is "editline", which has a useable license.
---
 .travis/deps.sh |  1 +
 makefile        | 12 ++++++++++
 scp.c           | 59 ++++++++++---------------------------------------
 3 files changed, 25 insertions(+), 47 deletions(-)

diff --git a/.travis/deps.sh b/.travis/deps.sh
index 0e7205fc..d799adb6 100755
--- a/.travis/deps.sh
+++ b/.travis/deps.sh
@@ -12,6 +12,7 @@ install_linux() {
     sudo apt-get install -ym libegl1-mesa-dev libgles2-mesa-dev
     sudo apt-get install -ym libsdl2-dev libpcap-dev libvdeplug-dev
     sudo apt-get install -ym libsdl2-ttf-dev
+    sudo apt-get install -ym libedit-dev
 }
 
 install_"$1"
diff --git a/makefile b/makefile
index ae3b81f8..a055314e 100644
--- a/makefile
+++ b/makefile
@@ -607,6 +607,18 @@ ifeq (${WIN32},)  #*nix Environments (&& cygwin)
       endif
     endif
   endif
+  ifneq (,$(call find_include,editline/readline))
+    OS_CCDEFS += -DHAVE_EDITLINE
+    OS_LDFLAGS += -ledit
+    ifneq (Darwin,$(OSTYPE))
+      # The doc says termcap is needed, though reality suggests
+      # otherwise.  Put it in anyway, it can't hurt.
+      ifneq (,$(call find_lib,termcap))
+        OS_LDFLAGS += -ltermcap
+      endif
+    endif
+    $(info using libedit: $(call find_include,editline/readline))
+  endif
   ifneq (,$(call find_include,utime))
     OS_CCDEFS += -DHAVE_UTIME
   endif
diff --git a/scp.c b/scp.c
index 9a586589..92c8f90e 100644
--- a/scp.c
+++ b/scp.c
@@ -242,8 +242,8 @@
 #endif
 #include <setjmp.h>
 
-#if defined(SIM_HAVE_DLOPEN)                                /* Dynamic Readline support */
-#include <dlfcn.h>
+#if defined(HAVE_EDITLINE)              /* Editline command line editing */
+#include <editline/readline.h>
 #endif
 
 #ifndef MAX
@@ -10273,51 +10273,16 @@ return read_line_p (NULL, cptr, size, stream);
 char *read_line_p (const char *prompt, char *cptr, int32 size, FILE *stream)
 {
 char *tptr;
-#if defined(SIM_HAVE_DLOPEN)
-static int initialized = 0;
-typedef char *(*readline_func)(const char *);
-static readline_func p_readline = NULL;
-typedef void (*add_history_func)(const char *);
-static add_history_func p_add_history = NULL;
-
-if (prompt && (!initialized)) {
-    initialized = 1;
-    void *handle;
-
-#define S__STR_QUOTE(tok) #tok
-#define S__STR(tok) S__STR_QUOTE(tok)
-    handle = dlopen("libncurses." S__STR(SIM_HAVE_DLOPEN), RTLD_NOW|RTLD_GLOBAL);
-    handle = dlopen("libcurses." S__STR(SIM_HAVE_DLOPEN), RTLD_NOW|RTLD_GLOBAL);
-    handle = dlopen("libreadline." S__STR(SIM_HAVE_DLOPEN), RTLD_NOW|RTLD_GLOBAL);
-    if (!handle)
-        handle = dlopen("libreadline." S__STR(SIM_HAVE_DLOPEN) ".8", RTLD_NOW|RTLD_GLOBAL);
-    if (!handle)
-        handle = dlopen("libreadline." S__STR(SIM_HAVE_DLOPEN) ".7", RTLD_NOW|RTLD_GLOBAL);
-    if (!handle)
-        handle = dlopen("libreadline." S__STR(SIM_HAVE_DLOPEN) ".6", RTLD_NOW|RTLD_GLOBAL);
-    if (!handle)
-        handle = dlopen("libreadline." S__STR(SIM_HAVE_DLOPEN) ".5", RTLD_NOW|RTLD_GLOBAL);
-    if (handle) {
-        p_readline = (readline_func)((size_t)dlsym(handle, "readline"));
-        p_add_history = (add_history_func)((size_t)dlsym(handle, "add_history"));
-        }
-    }
+#if defined(HAVE_EDITLINE)
 if (prompt) {                                           /* interactive? */
-    if (p_readline) {
-        char *tmpc = p_readline (prompt);               /* get cmd line */
-        if (tmpc == NULL)                               /* bad result? */
-            cptr = NULL;
-        else {
-            strlcpy (cptr, tmpc, size);                 /* copy result */
-            free (tmpc) ;                               /* free temp */
-            }
-        }
+    char *tmpc = readline (prompt);                     /* get cmd line */
+    if (tmpc == NULL)                                   /* bad result? */
+        cptr = NULL;
     else {
-        printf ("%s", prompt);                          /* display prompt */
-        fflush (stdout);
-        cptr = fgets (cptr, size, stream);              /* get cmd line */
-        }
+        strlcpy (cptr, tmpc, size);                     /* copy result */
+        free (tmpc) ;                                   /* free temp */
     }
+}
 else cptr = fgets (cptr, size, stream);                 /* get cmd line */
 #else
 if (prompt) {                                           /* interactive? */
@@ -10349,9 +10314,9 @@ if ((*cptr == ';') || (*cptr == '#')) {                 /* ignore comment */
     *cptr = 0;
     }
 
-#if defined (SIM_HAVE_DLOPEN)
-if (prompt && p_add_history && *cptr)                   /* Save non blank lines in history */
-    p_add_history (cptr);
+#if defined (HAVE_EDITLINE)
+if (prompt && *cptr)                   /* Save non blank lines in history */
+    add_history (cptr);
 #endif
 
 return cptr;