Ignore compatible mode

src/nvim/ex_docmd.c

@@ -6961,15 +6961,6 @@ static void ex_mkrc(exarg_T *eap)
         failed = TRUE;
     }
 
-    if (eap->cmdidx != CMD_mkview) {
-      /* Write setting 'compatible' first, because it has side effects.
-       * For that same reason only do it when needed. */
-      if (p_cp)
-        (void)put_line(fd, "if !&cp | set cp | endif");
-      else
-        (void)put_line(fd, "if &cp | set nocp | endif");
-    }
-
     if (!view_session
         || (eap->cmdidx == CMD_mksession
             && (*flagp & SSOP_OPTIONS)))

src/nvim/globals.h

@@ -1229,6 +1229,7 @@ EXTERN char_u e_invalpat[] INIT(= N_(
 EXTERN char_u e_bufloaded[] INIT(= N_("E139: File is loaded in another buffer"));
 EXTERN char_u e_notset[] INIT(= N_("E764: Option '%s' is not set"));
 EXTERN char_u e_invalidreg[] INIT(= N_("E850: Invalid register name"));
+EXTERN char_u e_unsupportedoption[] INIT(= N_("E519: Option not supported"));
 
 
 EXTERN char top_bot_msg[] INIT(= N_("search hit TOP, continuing at BOTTOM"));

src/nvim/main.c

@@ -955,7 +955,6 @@ static void parse_command_name(mparm_T *parmp)
       exmode_active = EXMODE_VIM;
     else
       exmode_active = EXMODE_NORMAL;
-    change_compatible(TRUE);            /* set 'compatible' */
   }
 }
 
@@ -1090,10 +1089,6 @@ static void command_line_scan(mparm_T *parmp)
           curbuf->b_p_bin = 1;                /* binary file I/O */
           break;
 
-        case 'C':                 /* "-C"  Compatible */
-          change_compatible(TRUE);
-          break;
-
         case 'e':                 /* "-e" Ex mode */
           exmode_active = EXMODE_NORMAL;
           break;
@@ -1142,7 +1137,7 @@ static void command_line_scan(mparm_T *parmp)
           break;
 
         case 'N':                 /* "-N"  Nocompatible */
-          change_compatible(FALSE);
+          /* No-op */
           break;
 
         case 'n':                 /* "-n" no swap file */
@@ -2207,8 +2202,6 @@ static void usage(void)
   main_msg(_("-M\t\t\tModifications in text not allowed"));
   main_msg(_("-b\t\t\tBinary mode"));
   main_msg(_("-l\t\t\tLisp mode"));
-  main_msg(_("-C\t\t\tCompatible with Vi: 'compatible'"));
-  main_msg(_("-N\t\t\tNot fully Vi compatible: 'nocompatible'"));
   main_msg(_("-V[N][fname]\t\tBe verbose [level N] [log messages to fname]"));
   main_msg(_("-D\t\t\tDebugging mode"));
   main_msg(_("-n\t\t\tNo swap file, use memory only"));

src/nvim/message.c

@@ -839,7 +839,7 @@ void wait_return(int redraw)
        * to avoid that typing one 'j' too many makes the messages
        * disappear.
        */
-      if (p_more && !p_cp) {
+      if (p_more) {
         if (c == 'b' || c == 'k' || c == 'u' || c == 'g'
             || c == K_UP || c == K_PAGEUP) {
           if (msg_scrolled > Rows)

src/nvim/option.c

@@ -1851,8 +1851,8 @@ void set_init_1(void)
 
   langmap_init();
 
-  /* Be Vi compatible by default */
-  p_cp = TRUE;
+  /* Be nocompatible */
+  p_cp = FALSE;
 
   /* Use POSIX compatibility when $VIM_POSIX is set. */
   if (os_getenv("VIM_POSIX") != NULL) {
@@ -1995,6 +1995,9 @@ void set_init_1(void)
   check_win_options(curwin);
   check_options();
 
+  /* Set all options to their Vim default */
+  set_options_default(OPT_FREE);
+
   /* Must be before option_expand(), because that one needs vim_isIDc() */
   didset_options();
 
@@ -2617,7 +2620,7 @@ do_set (
           if (vim_strchr((char_u *)"=:!&<", nextchar) == NULL
               && (!(options[opt_idx].flags & P_BOOL)
                   || nextchar == '?'))
-            errmsg = (char_u *)N_("E519: Option not supported");
+            errmsg = (char_u *)_(e_unsupportedoption);
           goto skip;
         }
 
@@ -4922,13 +4925,10 @@ set_bool_option (
   if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
     *(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL) = value;
 
-  /*
-   * Handle side effects of changing a bool option.
-   */
-
-  /* 'compatible' */
-  if ((int *)varp == &p_cp) {
-    compatible_set();
+  if ((int *)varp == &p_cp && p_cp == TRUE) {
+    /* Ensure that compatible can not be enabled */
+    p_cp = FALSE;
+    return e_unsupportedoption;
   }
   /* 'undofile' */
   else if ((int *)varp == &curbuf->b_p_udf || (int *)varp == &p_udf) {
@@ -7748,18 +7748,9 @@ static void paste_option_changed(void)
  */
 void vimrc_found(char_u *fname, char_u *envname)
 {
-  int opt_idx;
   int dofree = FALSE;
   char_u      *p;
 
-  if (!option_was_set((char_u *)"cp")) {
-    p_cp = FALSE;
-    for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
-      if (!(options[opt_idx].flags & (P_WAS_SET|P_VI_DEF)))
-        set_option_default(opt_idx, OPT_FREE, FALSE);
-    didset_options();
-  }
-
   if (fname != NULL) {
     p = vim_getenv(envname, &dofree);
     if (p == NULL) {
@@ -7774,22 +7765,6 @@ void vimrc_found(char_u *fname, char_u *envname)
   }
 }
 
-/*
- * Set 'compatible' on or off.  Called for "-C" and "-N" command line arg.
- */
-void change_compatible(int on)
-{
-  int opt_idx;
-
-  if (p_cp != on) {
-    p_cp = on;
-    compatible_set();
-  }
-  opt_idx = findoption((char_u *)"cp");
-  if (opt_idx >= 0)
-    options[opt_idx].flags |= P_WAS_SET;
-}
-
 /*
  * Return TRUE when option "name" has been set.
  * Only works correctly for global options.
@@ -7817,25 +7792,6 @@ void reset_option_was_set(char_u *name)
     options[idx].flags &= ~P_WAS_SET;
 }
 
-/*
- * compatible_set() - Called when 'compatible' has been set or unset.
- *
- * When 'compatible' set: Set all relevant options (those that have the P_VIM)
- * flag) to a Vi compatible value.
- * When 'compatible' is unset: Set all options that have a different default
- * for Vim (without the P_VI_DEF flag) to that default.
- */
-static void compatible_set(void)
-{
-  int opt_idx;
-
-  for (opt_idx = 0; !istermoption(&options[opt_idx]); opt_idx++)
-    if (       ((options[opt_idx].flags & P_VIM) && p_cp)
-               || (!(options[opt_idx].flags & P_VI_DEF) && !p_cp))
-      set_option_default(opt_idx, OPT_FREE, p_cp);
-  didset_options();
-}
-
 /*
  * fill_breakat_flags() -- called when 'breakat' changes value.
  */

src/nvim/version.c

@@ -944,12 +944,6 @@ void intro_message(int colon)
   if (((row >= 2) && (Columns >= 50)) || colon) {
     for (i = 0; i < (int)(sizeof(lines) / sizeof(char *)); ++i) {
       p = lines[i];
-      if (p == NULL) {
-        if (!p_cp) {
-          break;
-        }
-        continue;
-      }
 
       if (sponsor != 0) {
         if (strstr(p, "children") != NULL) {