patch 8.0.0334: can't access b:changedtick from a dict reference

Problem:    Can't access b:changedtick from a dict reference.
Solution:   Make changedtick a member of the b: dict. (inspired by neovim
            #6112)

Author: brammool

src/Makefile

@@ -2099,6 +2099,7 @@ test_arglist \
 	test_cdo \
 	test_channel \
 	test_charsearch \
+	test_changedtick \
 	test_cmdline \
 	test_command_count \
 	test_crypt \

src/buffer.c

@@ -832,6 +832,7 @@ free_buffer(buf_T *buf)
     free_buffer_stuff(buf, TRUE);
 #ifdef FEAT_EVAL
     unref_var_dict(buf->b_vars);
+    buf->b_changedtick = &buf->b_ct_val;
 #endif
 #ifdef FEAT_LUA
     lua_buffer_free(buf);
@@ -872,6 +873,29 @@ free_buffer(buf_T *buf)
 	vim_free(buf);
 }
 
+/*
+ * Initializes buf->b_changedtick.
+ */
+    static void
+init_changedtick(buf_T *buf)
+{
+#ifdef FEAT_EVAL
+    dictitem_T *di = dictitem_alloc((char_u *)"changedtick");
+
+    if (di != NULL)
+    {
+	di->di_flags |= DI_FLAGS_LOCK | DI_FLAGS_FIX | DI_FLAGS_RO;
+	di->di_tv.v_type = VAR_NUMBER;
+	di->di_tv.v_lock = VAR_FIXED;
+	di->di_tv.vval.v_number = 0;
+	dict_add(buf->b_vars, di);
+	buf->b_changedtick = &di->di_tv.vval.v_number;
+    }
+    else
+#endif
+	buf->b_changedtick = &buf->b_ct_val;
+}
+
 /*
  * Free stuff in the buffer for ":bdel" and when wiping out the buffer.
  */
@@ -889,8 +913,14 @@ free_buffer_stuff(
 #endif
     }
 #ifdef FEAT_EVAL
-    vars_clear(&buf->b_vars->dv_hashtab); /* free all internal variables */
-    hash_init(&buf->b_vars->dv_hashtab);
+    {
+	varnumber_T tick = *buf->b_changedtick;
+
+	vars_clear(&buf->b_vars->dv_hashtab); /* free all buffer variables */
+	hash_init(&buf->b_vars->dv_hashtab);
+	init_changedtick(buf);
+	*buf->b_changedtick = tick;
+    }
 #endif
 #ifdef FEAT_USR_CMDS
     uc_clear(&buf->b_ucmds);		/* clear local user commands */
@@ -1979,6 +2009,7 @@ buflist_new(
 	}
 	init_var_dict(buf->b_vars, &buf->b_bufvar, VAR_SCOPE);
 #endif
+	init_changedtick(buf);
     }
 
     if (ffname != NULL)

src/edit.c

@@ -1668,7 +1668,7 @@ ins_redraw(
 #ifdef FEAT_AUTOCMD
     /* Trigger TextChangedI if b_changedtick differs. */
     if (ready && has_textchangedI()
-	    && last_changedtick != curbuf->b_changedtick
+	    && last_changedtick != *curbuf->b_changedtick
 # ifdef FEAT_INS_EXPAND
 	    && !pum_visible()
 # endif
@@ -1677,7 +1677,7 @@ ins_redraw(
 	if (last_changedtick_buf == curbuf)
 	    apply_autocmds(EVENT_TEXTCHANGEDI, NULL, NULL, FALSE, curbuf);
 	last_changedtick_buf = curbuf;
-	last_changedtick = curbuf->b_changedtick;
+	last_changedtick = *curbuf->b_changedtick;
     }
 #endif
 

src/eval.c

@@ -1451,14 +1451,8 @@ list_glob_vars(int *first)
     static void
 list_buf_vars(int *first)
 {
-    char_u	numbuf[NUMBUFLEN];
-
     list_hashtable_vars(&curbuf->b_vars->dv_hashtab, (char_u *)"b:",
 								 TRUE, first);
-
-    sprintf((char *)numbuf, "%ld", (long)curbuf->b_changedtick);
-    list_one_var_a((char_u *)"b:", (char_u *)"changedtick", VAR_NUMBER,
-							       numbuf, first);
 }
 
 /*
@@ -1805,20 +1799,6 @@ ex_let_one(
     return arg_end;
 }
 
-/*
- * If "arg" is equal to "b:changedtick" give an error and return TRUE.
- */
-    int
-check_changedtick(char_u *arg)
-{
-    if (STRNCMP(arg, "b:changedtick", 13) == 0 && !eval_isnamec(arg[13]))
-    {
-	EMSG2(_(e_readonlyvar), arg);
-	return TRUE;
-    }
-    return FALSE;
-}
-
 /*
  * Get an lval: variable, Dict item or List item that can be assigned a value
  * to: "name", "na{me}", "name[expr]", "name[expr:expr]", "name[expr][expr]",
@@ -2208,32 +2188,29 @@ set_var_lval(
 
     if (lp->ll_tv == NULL)
     {
-	if (!check_changedtick(lp->ll_name))
+	cc = *endp;
+	*endp = NUL;
+	if (op != NULL && *op != '=')
 	{
-	    cc = *endp;
-	    *endp = NUL;
-	    if (op != NULL && *op != '=')
-	    {
-		typval_T tv;
+	    typval_T tv;
 
-		/* handle +=, -= and .= */
-		di = NULL;
-		if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
-						 &tv, &di, TRUE, FALSE) == OK)
-		{
-		    if ((di == NULL
-			   || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
-			      && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
-								      FALSE)))
-			    && tv_op(&tv, rettv, op) == OK)
-			set_var(lp->ll_name, &tv, FALSE);
-		    clear_tv(&tv);
-		}
+	    /* handle +=, -= and .= */
+	    di = NULL;
+	    if (get_var_tv(lp->ll_name, (int)STRLEN(lp->ll_name),
+					     &tv, &di, TRUE, FALSE) == OK)
+	    {
+		if ((di == NULL
+		       || (!var_check_ro(di->di_flags, lp->ll_name, FALSE)
+			  && !tv_check_lock(di->di_tv.v_lock, lp->ll_name,
+								  FALSE)))
+			&& tv_op(&tv, rettv, op) == OK)
+		    set_var(lp->ll_name, &tv, FALSE);
+		clear_tv(&tv);
 	    }
-	    else
-		set_var(lp->ll_name, rettv, copy);
-	    *endp = cc;
 	}
+	else
+	    set_var(lp->ll_name, rettv, copy);
+	*endp = cc;
     }
     else if (tv_check_lock(lp->ll_newkey == NULL
 		? lp->ll_tv->v_lock
@@ -2776,9 +2753,7 @@ do_unlet_var(
 	*name_end = NUL;
 
 	/* Normal name or expanded name. */
-	if (check_changedtick(lp->ll_name))
-	    ret = FAIL;
-	else if (do_unlet(lp->ll_name, forceit) == FAIL)
+	if (do_unlet(lp->ll_name, forceit) == FAIL)
 	    ret = FAIL;
 	*name_end = cc;
     }
@@ -2904,21 +2879,16 @@ do_lock_var(
 	*name_end = NUL;
 
 	/* Normal name or expanded name. */
-	if (check_changedtick(lp->ll_name))
+	di = find_var(lp->ll_name, NULL, TRUE);
+	if (di == NULL)
 	    ret = FAIL;
 	else
 	{
-	    di = find_var(lp->ll_name, NULL, TRUE);
-	    if (di == NULL)
-		ret = FAIL;
+	    if (lock)
+		di->di_flags |= DI_FLAGS_LOCK;
 	    else
-	    {
-		if (lock)
-		    di->di_flags |= DI_FLAGS_LOCK;
-		else
-		    di->di_flags &= ~DI_FLAGS_LOCK;
-		item_lock(&di->di_tv, deep, lock);
-	    }
+		di->di_flags &= ~DI_FLAGS_LOCK;
+	    item_lock(&di->di_tv, deep, lock);
 	}
 	*name_end = cc;
     }
@@ -3139,11 +3109,6 @@ get_user_var_name(expand_T *xp, int idx)
 	    ++hi;
 	return cat_prefix_varname('b', hi->hi_key);
     }
-    if (bdone == ht->ht_used)
-    {
-	++bdone;
-	return (char_u *)"b:changedtick";
-    }
 
     /* w: variables */
     ht = &curwin->w_vars->dv_hashtab;
@@ -6815,36 +6780,22 @@ get_var_tv(
 {
     int		ret = OK;
     typval_T	*tv = NULL;
-    typval_T	atv;
     dictitem_T	*v;
     int		cc;
 
     /* truncate the name, so that we can use strcmp() */
     cc = name[len];
     name[len] = NUL;
 
-    /*
-     * Check for "b:changedtick".
-     */
-    if (STRCMP(name, "b:changedtick") == 0)
-    {
-	atv.v_type = VAR_NUMBER;
-	atv.vval.v_number = curbuf->b_changedtick;
-	tv = &atv;
-    }
-
     /*
      * Check for user-defined variables.
      */
-    else
+    v = find_var(name, NULL, no_autoload);
+    if (v != NULL)
     {
-	v = find_var(name, NULL, no_autoload);
-	if (v != NULL)
-	{
-	    tv = &v->di_tv;
-	    if (dip != NULL)
-		*dip = v;
-	}
+	tv = &v->di_tv;
+	if (dip != NULL)
+	    *dip = v;
     }
 
     if (tv == NULL)

src/evalfunc.c

@@ -2539,7 +2539,7 @@ f_diff_hlID(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
 #ifdef FEAT_DIFF
     linenr_T		lnum = get_tv_lnum(argvars);
     static linenr_T	prev_lnum = 0;
-    static int		changedtick = 0;
+    static varnumber_T	changedtick = 0;
     static int		fnum = 0;
     static int		change_start = 0;
     static int		change_end = 0;
@@ -2550,7 +2550,7 @@ f_diff_hlID(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
     if (lnum < 0)	/* ignore type error in {lnum} arg */
 	lnum = 0;
     if (lnum != prev_lnum
-	    || changedtick != curbuf->b_changedtick
+	    || changedtick != *curbuf->b_changedtick
 	    || fnum != curbuf->b_fnum)
     {
 	/* New line, buffer, change: need to get the values. */
@@ -2572,7 +2572,7 @@ f_diff_hlID(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
 	else
 	    hlID = (hlf_T)0;
 	prev_lnum = lnum;
-	changedtick = curbuf->b_changedtick;
+	changedtick = *curbuf->b_changedtick;
 	fnum = curbuf->b_fnum;
     }
 
@@ -3957,7 +3957,7 @@ get_buffer_info(buf_T *buf)
     dict_add_nr_str(dict, "loaded", buf->b_ml.ml_mfp != NULL, NULL);
     dict_add_nr_str(dict, "listed", buf->b_p_bl, NULL);
     dict_add_nr_str(dict, "changed", bufIsChanged(buf), NULL);
-    dict_add_nr_str(dict, "changedtick", buf->b_changedtick, NULL);
+    dict_add_nr_str(dict, "changedtick", *buf->b_changedtick, NULL);
     dict_add_nr_str(dict, "hidden",
 		    buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0,
 		    NULL);
@@ -4190,12 +4190,6 @@ f_getbufvar(typval_T *argvars, typval_T *rettv)
 		/* buffer-local-option */
 		done = TRUE;
 	}
-	else if (STRCMP(varname, "changedtick") == 0)
-	{
-	    rettv->v_type = VAR_NUMBER;
-	    rettv->vval.v_number = curbuf->b_changedtick;
-	    done = TRUE;
-	}
 	else
 	{
 	    /* Look up the variable. */
@@ -6576,21 +6570,16 @@ f_islocked(typval_T *argvars, typval_T *rettv)
 	{
 	    if (lv.ll_tv == NULL)
 	    {
-		if (check_changedtick(lv.ll_name))
-		    rettv->vval.v_number = 1;	    /* always locked */
-		else
+		di = find_var(lv.ll_name, NULL, TRUE);
+		if (di != NULL)
 		{
-		    di = find_var(lv.ll_name, NULL, TRUE);
-		    if (di != NULL)
-		    {
-			/* Consider a variable locked when:
-			 * 1. the variable itself is locked
-			 * 2. the value of the variable is locked.
-			 * 3. the List or Dict value is locked.
-			 */
-			rettv->vval.v_number = ((di->di_flags & DI_FLAGS_LOCK)
-						  || tv_islocked(&di->di_tv));
-		    }
+		    /* Consider a variable locked when:
+		     * 1. the variable itself is locked
+		     * 2. the value of the variable is locked.
+		     * 3. the List or Dict value is locked.
+		     */
+		    rettv->vval.v_number = ((di->di_flags & DI_FLAGS_LOCK)
+						   || tv_islocked(&di->di_tv));
 		}
 	    }
 	    else if (lv.ll_range)
@@ -11551,8 +11540,8 @@ f_submatch(typval_T *argvars, typval_T *rettv)
 	return;
     if (no < 0 || no >= NSUBEXP)
     {
-        EMSGN(_("E935: invalid submatch number: %d"), no);
-        return;
+	EMSGN(_("E935: invalid submatch number: %d"), no);
+	return;
     }
     if (argvars[1].v_type != VAR_UNKNOWN)
 	retList = (int)get_tv_number_chk(&argvars[1], &error);

src/ex_docmd.c

@@ -626,7 +626,7 @@ do_exmode(
     int		save_msg_scroll;
     int		prev_msg_row;
     linenr_T	prev_line;
-    int		changedtick;
+    varnumber_T	changedtick;
 
     if (improved)
 	exmode_active = EXMODE_VIM;
@@ -660,7 +660,7 @@ do_exmode(
 	need_wait_return = FALSE;
 	ex_pressedreturn = FALSE;
 	ex_no_reprint = FALSE;
-	changedtick = curbuf->b_changedtick;
+	changedtick = *curbuf->b_changedtick;
 	prev_msg_row = msg_row;
 	prev_line = curwin->w_cursor.lnum;
 	if (improved)
@@ -673,7 +673,7 @@ do_exmode(
 	lines_left = Rows - 1;
 
 	if ((prev_line != curwin->w_cursor.lnum
-		    || changedtick != curbuf->b_changedtick) && !ex_no_reprint)
+		   || changedtick != *curbuf->b_changedtick) && !ex_no_reprint)
 	{
 	    if (curbuf->b_ml.ml_flags & ML_EMPTY)
 		EMSG(_(e_emptybuf));

src/fileio.c

@@ -4926,9 +4926,9 @@ buf_write(
 #ifdef FEAT_AUTOCMD
 	/* buf->b_changedtick is always incremented in unchanged() but that
 	 * should not trigger a TextChanged event. */
-	if (last_changedtick + 1 == buf->b_changedtick
+	if (last_changedtick + 1 == *buf->b_changedtick
 					       && last_changedtick_buf == buf)
-	    last_changedtick = buf->b_changedtick;
+	    last_changedtick = *buf->b_changedtick;
 #endif
 	u_unchanged(buf);
 	u_update_save_nr(buf);