dynamic-libedit.patch

--- src/lua.c.orig      2018-07-19 19:12:54 UTC
+++ src/lua.c
@@ -73,6 +73,9 @@ static void print_usage (const char *bad
   "  -l name  require library 'name' into global 'name'\n"
   "  -v       show version information\n"
   "  -E       ignore environment variables\n"
+#if defined(LUA_USE_READLINE_DL)
+  "  -N       disable command-line editing\n"
+#endif
   "  --       stop handling options\n"
   "  -        stop handling options and execute stdin\n"
   ,
@@ -235,6 +238,7 @@ static int handle_script (lua_State *L, 
 #define has_v          4       /* -v */
 #define has_e          8       /* -e */
 #define has_E          16      /* -E */
+#define has_N          32      /* -N */
 
 
 /*
@@ -263,6 +267,13 @@ static int collectargs (char **argv, int
           return has_error;  /* invalid option */
         args |= has_E;
         break;
+#if defined(LUA_USE_READLINE_DL)
+      case 'N':
+        if (argv[i][2] != '\0')  /* extra characters after 1st? */
+          return has_error;  /* invalid option */
+        args |= has_N;
+        break;
+#endif
       case 'i':
         args |= has_i;  /* (-i implies -v) *//* FALLTHROUGH */
       case 'v':
@@ -379,7 +390,58 @@ static int handle_luainit (lua_State *L)
 */
 #if !defined(lua_readline)     /* { */
 
-#if defined(LUA_USE_READLINE)  /* { */
+#if defined(LUA_USE_READLINE_DL)/* { */
+
+#include <editline/readline.h>
+#include <dlfcn.h>
+
+#ifndef LUA_READLINE_LIBPATH
+#define LUA_READLINE_LIBPATH "/usr/local/lib/libedit.so"
+#endif
+
+typedef char *readline_functype(const char *);
+typedef int add_history_functype(const char *);
+
+static readline_functype *lua_readline_p = NULL;
+static add_history_functype *lua_saveline_p = NULL;
+static int disable_readline = 0;
+
+static void lua_initreadline(lua_State *L)
+{
+  void *editlib = NULL;
+  union dl_func_hack {
+    void *ptr;
+    readline_functype *rlfunc;
+    add_history_functype *ahfunc;
+    char **rlnamevar;
+    int *icompvar;
+  } u;
+  (void) L;
+  if (disable_readline)
+    return;
+  if ((editlib = dlopen(LUA_READLINE_LIBPATH, RTLD_LAZY | RTLD_LOCAL))) {
+    u.ptr = dlsym(editlib, "readline");
+    lua_readline_p = u.rlfunc;
+    u.ptr = dlsym(editlib, "add_history");
+    lua_saveline_p = u.ahfunc;
+    u.ptr = dlsym(editlib, "rl_readline_name");
+    if (u.ptr)
+      *u.rlnamevar = "lua";
+    u.ptr = dlsym(editlib, "rl_inhibit_completion");
+    if (u.ptr)
+      *u.icompvar = 1;
+  }
+}
+
+#define lua_readline(L,b,p) \
+    ((void)L,                                                          \
+     (lua_readline_p)                                                  \
+     ? (((b)=lua_readline_p(p)) != NULL)                               \
+     : (fputs(p, stdout), fflush(stdout), fgets(b, LUA_MAXINPUT, stdin) != NULL))
+#define lua_saveline(L,line)   do { (void)L; if (lua_saveline_p) lua_saveline_p(line); } while(0)
+#define lua_freeline(L,b)      do { (void)L; if (lua_readline_p) free(b); } while(0)
+
+#elif defined(LUA_USE_READLINE)        /* { */
 
 #include <readline/readline.h>
 #include <readline/history.h>
@@ -590,6 +652,10 @@ static int pmain (lua_State *L) {
   if (script < argc &&  /* execute main script (if there is one) */
       handle_script(L, argv + script) != LUA_OK)
     return 0;
+#if defined(LUA_USE_READLINE_DL)
+  if (args & has_N)
+    disable_readline = 1;
+#endif
   if (args & has_i)  /* -i option? */
     doREPL(L);  /* do read-eval-print loop */
   else if (script == argc && !(args & (has_e | has_v))) {  /* no arguments? */