diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 34712cbce7..3b6be28bf8 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2848,7 +2848,8 @@ str2list({expr} [, {utf8}])	List	convert each character of {expr} to
 str2nr({expr} [, {base} [, {quoted}]])
 				Number	convert String to Number
 strcharpart({str}, {start} [, {len}])
-				String	{len} characters of {str} at {start}
+				String	{len} characters of {str} at
+					character {start}
 strchars({expr} [, {skipcc}])	Number	character length of the String {expr}
 strdisplaywidth({expr} [, {col}]) Number display length of the String {expr}
 strftime({format} [, {time}])	String	format time with a specified format
@@ -2857,8 +2858,9 @@ stridx({haystack}, {needle} [, {start}])
 				Number	index of {needle} in {haystack}
 string({expr})			String	String representation of {expr} value
 strlen({expr})			Number	length of the String {expr}
-strpart({str}, {start} [, {len}])
-				String	{len} bytes of {str} at byte {start}
+strpart({str}, {start} [, {len} [, {chars}]])
+				String	{len} bytes/chars of {str} at
+					byte {start}
 strptime({format}, {timestring})
 				Number	Convert {timestring} to unix timestamp
 strridx({haystack}, {needle} [, {start}])
@@ -3430,7 +3432,8 @@ byte2line({byte})					*byte2line()*
 
 byteidx({expr}, {nr})					*byteidx()*
 		Return byte index of the {nr}'th character in the string
-		{expr}.  Use zero for the first character, it returns zero.
+		{expr}.  Use zero for the first character, it then returns
+		zero.
 		This function is only useful when there are multibyte
 		characters, otherwise the returned value is equal to {nr}.
 		Composing characters are not counted separately, their byte
@@ -9960,17 +9963,22 @@ strlen({expr})	The result is a Number, which is the length of the String
 		{expr} in bytes.
 		If the argument is a Number it is first converted to a String.
 		For other types an error is given.
-		If you want to count the number of multi-byte characters use
+		If you want to count the number of multibyte characters use
 		|strchars()|.
 		Also see |len()|, |strdisplaywidth()| and |strwidth()|.
 
 		Can also be used as a |method|: >
 			GetString()->strlen()
 
-strpart({src}, {start} [, {len}])			*strpart()*
+strpart({src}, {start} [, {len} [, {chars}]])			*strpart()*
 		The result is a String, which is part of {src}, starting from
 		byte {start}, with the byte length {len}.
-		To count characters instead of bytes use |strcharpart()|.
+		When {chars} is present and TRUE then {len} is the number of
+		characters positions (composing characters are not counted
+		separately, thus "1" means one base character and any
+		following composing characters).
+		To count {start} as characters instead of bytes use
+		|strcharpart()|.
 
 		When bytes are selected which do not exist, this doesn't
 		result in an error, the bytes are simply omitted.
@@ -9982,8 +9990,8 @@ strpart({src}, {start} [, {len}])			*strpart()*
 			strpart("abcdefg", 3)	    == "defg"
 
 <		Note: To get the first character, {start} must be 0.  For
-		example, to get three bytes under and after the cursor: >
-			strpart(getline("."), col(".") - 1, 3)
+		example, to get the character under the cursor: >
+			strpart(getline("."), col(".") - 1, 1, v:true)
 <
 		Can also be used as a |method|: >
 			GetText()->strpart(5)
diff --git a/src/channel.c b/src/channel.c
index b9c8566e52..8ded2ced0c 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -923,7 +923,7 @@ channel_connect(
 	    *waittime -= elapsed_msec;
 	    if (waitnow > 0)
 	    {
-		mch_delay((long)waitnow, TRUE);
+		mch_delay((long)waitnow, MCH_DELAY_IGNOREINPUT);
 		ui_breakcheck();
 		*waittime -= waitnow;
 	    }
diff --git a/src/eval.c b/src/eval.c
index 056ac76c2a..2d2ad1b5fa 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2675,6 +2675,7 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	int	    oplen;
 	int	    concat;
 	typval_T    var2;
+	int	    vim9script = in_vim9script();
 
 	// "." is only string concatenation when scriptversion is 1
 	p = eval_next_non_blank(*arg, evalarg, &getnext);
@@ -2689,7 +2690,7 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	    *arg = eval_next_line(evalarg);
 	else
 	{
-	    if (evaluate && in_vim9script() && !VIM_ISWHITE(**arg))
+	    if (evaluate && vim9script && !VIM_ISWHITE(**arg))
 	    {
 		error_white_both(p, oplen);
 		clear_tv(rettv);
@@ -2721,14 +2722,14 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	/*
 	 * Get the second variable.
 	 */
-	if (evaluate && in_vim9script() && !IS_WHITE_OR_NUL((*arg)[oplen]))
+	if (evaluate && vim9script && !IS_WHITE_OR_NUL((*arg)[oplen]))
 	{
 	    error_white_both(p, oplen);
 	    clear_tv(rettv);
 	    return FAIL;
 	}
 	*arg = skipwhite_and_linebreak(*arg + oplen, evalarg);
-	if (eval6(arg, &var2, evalarg, !in_vim9script() && op == '.') == FAIL)
+	if (eval6(arg, &var2, evalarg, !vim9script && op == '.') == FAIL)
 	{
 	    clear_tv(rettv);
 	    return FAIL;
@@ -2745,12 +2746,12 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 		char_u	*s1 = tv_get_string_buf(rettv, buf1);
 		char_u	*s2 = NULL;
 
-		if (in_vim9script() && (var2.v_type == VAR_VOID
+		if (vim9script && (var2.v_type == VAR_VOID
 			|| var2.v_type == VAR_CHANNEL
 			|| var2.v_type == VAR_JOB))
 		    emsg(_(e_inval_string));
 #ifdef FEAT_FLOAT
-		else if (var2.v_type == VAR_FLOAT)
+		else if (vim9script && var2.v_type == VAR_FLOAT)
 		{
 		    vim_snprintf((char *)buf2, NUMBUFLEN, "%g",
 							    var2.vval.v_float);
diff --git a/src/evalfunc.c b/src/evalfunc.c
index f85c05ee8f..eeeb180fdc 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -950,7 +950,7 @@ static funcentry_T global_functions[] =
     {"stridx",		2, 3, FEARG_1,	  ret_number,	f_stridx},
     {"string",		1, 1, FEARG_1,	  ret_string,	f_string},
     {"strlen",		1, 1, FEARG_1,	  ret_number,	f_strlen},
-    {"strpart",		2, 3, FEARG_1,	  ret_string,	f_strpart},
+    {"strpart",		2, 4, FEARG_1,	  ret_string,	f_strpart},
     {"strptime",	2, 2, FEARG_1,	  ret_number,
 #ifdef HAVE_STRPTIME
 	    f_strptime
@@ -8305,10 +8305,8 @@ f_strpart(typval_T *argvars, typval_T *rettv)
     else
 	len = slen - n;	    // default len: all bytes that are available.
 
-    /*
-     * Only return the overlap between the specified part and the actual
-     * string.
-     */
+    // Only return the overlap between the specified part and the actual
+    // string.
     if (n < 0)
     {
 	len += n;
@@ -8321,6 +8319,16 @@ f_strpart(typval_T *argvars, typval_T *rettv)
     else if (n + len > slen)
 	len = slen - n;
 
+    if (argvars[2].v_type != VAR_UNKNOWN && argvars[3].v_type != VAR_UNKNOWN)
+    {
+	int off;
+
+	// length in characters
+	for (off = n; off < slen && len > 0; --len)
+	    off += mb_ptr2len(p + off);
+	len = off - n;
+    }
+
     rettv->v_type = VAR_STRING;
     rettv->vval.v_string = vim_strnsave(p + n, len);
 }
diff --git a/src/evalvars.c b/src/evalvars.c
index c43bf585a2..26e15ddfb9 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -2463,6 +2463,20 @@ eval_variable(
 		tv = sv->sv_tv;
 	    }
 	}
+	else if (in_vim9script())
+	{
+	    ufunc_T *ufunc = find_func(name, FALSE, NULL);
+
+	    if (ufunc != NULL)
+	    {
+		foundFunc = TRUE;
+		if (rettv != NULL)
+		{
+		    rettv->v_type = VAR_FUNC;
+		    rettv->vval.v_string = vim_strsave(ufunc->uf_name);
+		}
+	    }
+	}
     }
 
     if (!foundFunc)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 4951724817..7c7d9e7a46 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -66,7 +66,9 @@ static int	getargopt(exarg_T *eap);
 # define ex_cexpr		ex_ni
 #endif
 
+static linenr_T default_address(exarg_T *eap);
 static linenr_T get_address(exarg_T *, char_u **, cmd_addr_T addr_type, int skip, int silent, int to_other_file, int address_count);
+static void address_default_all(exarg_T *eap);
 static void	get_flags(exarg_T *eap);
 #if !defined(FEAT_PERL) \
 	|| !defined(FEAT_PYTHON) || !defined(FEAT_PYTHON3) \
@@ -1886,7 +1888,9 @@ do_one_cmd(
 
     ea.cmd = cmd;
 #ifdef FEAT_EVAL
-    if (may_have_range)
+    if (!may_have_range)
+	ea.line1 = ea.line2 = default_address(&ea);
+    else
 #endif
 	if (parse_cmd_address(&ea, &errormsg, FALSE) == FAIL)
 	    goto doend;
@@ -2288,59 +2292,7 @@ do_one_cmd(
     }
 
     if ((ea.argt & EX_DFLALL) && ea.addr_count == 0)
-    {
-	buf_T	    *buf;
-
-	ea.line1 = 1;
-	switch (ea.addr_type)
-	{
-	    case ADDR_LINES:
-	    case ADDR_OTHER:
-		ea.line2 = curbuf->b_ml.ml_line_count;
-		break;
-	    case ADDR_LOADED_BUFFERS:
-		buf = firstbuf;
-		while (buf->b_next != NULL && buf->b_ml.ml_mfp == NULL)
-		    buf = buf->b_next;
-		ea.line1 = buf->b_fnum;
-		buf = lastbuf;
-		while (buf->b_prev != NULL && buf->b_ml.ml_mfp == NULL)
-		    buf = buf->b_prev;
-		ea.line2 = buf->b_fnum;
-		break;
-	    case ADDR_BUFFERS:
-		ea.line1 = firstbuf->b_fnum;
-		ea.line2 = lastbuf->b_fnum;
-		break;
-	    case ADDR_WINDOWS:
-		ea.line2 = LAST_WIN_NR;
-		break;
-	    case ADDR_TABS:
-		ea.line2 = LAST_TAB_NR;
-		break;
-	    case ADDR_TABS_RELATIVE:
-		ea.line2 = 1;
-		break;
-	    case ADDR_ARGUMENTS:
-		if (ARGCOUNT == 0)
-		    ea.line1 = ea.line2 = 0;
-		else
-		    ea.line2 = ARGCOUNT;
-		break;
-	    case ADDR_QUICKFIX_VALID:
-#ifdef FEAT_QUICKFIX
-		ea.line2 = qf_get_valid_size(&ea);
-		if (ea.line2 == 0)
-		    ea.line2 = 1;
-#endif
-		break;
-	    case ADDR_NONE:
-	    case ADDR_UNSIGNED:
-	    case ADDR_QUICKFIX:
-		iemsg(_("INTERNAL: Cannot use EX_DFLALL with ADDR_NONE, ADDR_UNSIGNED or ADDR_QUICKFIX"));
-		break;
-	}
-    }
+	address_default_all(&ea);
 
     // accept numbered register only when no count allowed (:put)
     if (       (ea.argt & EX_REGSTR)
@@ -3017,50 +2969,7 @@ parse_cmd_address(exarg_T *eap, char **errormsg, int silent)
     for (;;)
     {
 	eap->line1 = eap->line2;
-	switch (eap->addr_type)
-	{
-	    case ADDR_LINES:
-	    case ADDR_OTHER:
-		// Default is the cursor line number.  Avoid using an invalid
-		// line number though.
-		if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count)
-		    eap->line2 = curbuf->b_ml.ml_line_count;
-		else
-		    eap->line2 = curwin->w_cursor.lnum;
-		break;
-	    case ADDR_WINDOWS:
-		eap->line2 = CURRENT_WIN_NR;
-		break;
-	    case ADDR_ARGUMENTS:
-		eap->line2 = curwin->w_arg_idx + 1;
-		if (eap->line2 > ARGCOUNT)
-		    eap->line2 = ARGCOUNT;
-		break;
-	    case ADDR_LOADED_BUFFERS:
-	    case ADDR_BUFFERS:
-		eap->line2 = curbuf->b_fnum;
-		break;
-	    case ADDR_TABS:
-		eap->line2 = CURRENT_TAB_NR;
-		break;
-	    case ADDR_TABS_RELATIVE:
-	    case ADDR_UNSIGNED:
-		eap->line2 = 1;
-		break;
-	    case ADDR_QUICKFIX:
-#ifdef FEAT_QUICKFIX
-		eap->line2 = qf_get_cur_idx(eap);
-#endif
-		break;
-	    case ADDR_QUICKFIX_VALID:
-#ifdef FEAT_QUICKFIX
-		eap->line2 = qf_get_cur_valid_idx(eap);
-#endif
-		break;
-	    case ADDR_NONE:
-		// Will give an error later if a range is found.
-		break;
-	}
+	eap->line2 = default_address(eap);
 	eap->cmd = skipwhite(eap->cmd);
 	lnum = get_address(eap, &eap->cmd, eap->addr_type, eap->skip, silent,
 					eap->addr_count == 0, address_count++);
@@ -3248,6 +3157,27 @@ append_command(char_u *cmd)
     *d = NUL;
 }
 
+/*
+ * If "start" points "&opt", "&l:opt", "&g:opt" or "$ENV" return a pointer to
+ * the name.  Otherwise just return "start".
+ */
+    char_u *
+skip_option_env_lead(char_u *start)
+{
+    char_u *name = start;
+
+    if (*start == '&')
+    {
+	if ((start[1] == 'l' || start[1] == 'g') && start[2] == ':')
+	    name += 3;
+	else
+	    name += 1;
+    }
+    else if (*start == '$')
+	name += 1;
+    return name;
+}
+
 /*
  * Find an Ex command by its name, either built-in or user.
  * Start of the name can be found at eap->cmd.
@@ -3279,9 +3209,7 @@ find_ex_command(
     p = eap->cmd;
     if (lookup != NULL)
     {
-	// Skip over first char for "&opt = val", "$ENV = val" and "@r = val".
-	char_u *pskip = (*eap->cmd == '&' || *eap->cmd == '$')
-						     ? eap->cmd + 1 : eap->cmd;
+	char_u *pskip = skip_option_env_lead(eap->cmd);
 
 	if (vim_strchr((char_u *)"{('[\"@", *p) != NULL
 	       || ((p = to_name_const_end(pskip)) > eap->cmd && *p != NUL))
@@ -3659,6 +3587,61 @@ addr_error(cmd_addr_T addr_type)
 	emsg(_(e_invrange));
 }
 
+/*
+ * Return the default address for an address type.
+ */
+    static linenr_T
+default_address(exarg_T *eap)
+{
+    linenr_T lnum = 0;
+
+    switch (eap->addr_type)
+    {
+	case ADDR_LINES:
+	case ADDR_OTHER:
+	    // Default is the cursor line number.  Avoid using an invalid
+	    // line number though.
+	    if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count)
+		lnum = curbuf->b_ml.ml_line_count;
+	    else
+		lnum = curwin->w_cursor.lnum;
+	    break;
+	case ADDR_WINDOWS:
+	    lnum = CURRENT_WIN_NR;
+	    break;
+	case ADDR_ARGUMENTS:
+	    lnum = curwin->w_arg_idx + 1;
+	    if (lnum > ARGCOUNT)
+		lnum = ARGCOUNT;
+	    break;
+	case ADDR_LOADED_BUFFERS:
+	case ADDR_BUFFERS:
+	    lnum = curbuf->b_fnum;
+	    break;
+	case ADDR_TABS:
+	    lnum = CURRENT_TAB_NR;
+	    break;
+	case ADDR_TABS_RELATIVE:
+	case ADDR_UNSIGNED:
+	    lnum = 1;
+	    break;
+	case ADDR_QUICKFIX:
+#ifdef FEAT_QUICKFIX
+	    lnum = qf_get_cur_idx(eap);
+#endif
+	    break;
+	case ADDR_QUICKFIX_VALID:
+#ifdef FEAT_QUICKFIX
+	    lnum = qf_get_cur_valid_idx(eap);
+#endif
+	    break;
+	case ADDR_NONE:
+	    // Will give an error later if a range is found.
+	    break;
+    }
+    return lnum;
+}
+
 /*
  * Get a single EX address.
  *
@@ -4020,6 +4003,68 @@ error:
     return lnum;
 }
 
+/*
+ * Set eap->line1 and eap->line2 to the whole range.
+ * Used for commands with the EX_DFLALL flag and no range given.
+ */
+    static void
+address_default_all(exarg_T *eap)
+{
+    eap->line1 = 1;
+    switch (eap->addr_type)
+    {
+	case ADDR_LINES:
+	case ADDR_OTHER:
+	    eap->line2 = curbuf->b_ml.ml_line_count;
+	    break;
+	case ADDR_LOADED_BUFFERS:
+	    {
+		buf_T *buf = firstbuf;
+
+		while (buf->b_next != NULL && buf->b_ml.ml_mfp == NULL)
+		    buf = buf->b_next;
+		eap->line1 = buf->b_fnum;
+		buf = lastbuf;
+		while (buf->b_prev != NULL && buf->b_ml.ml_mfp == NULL)
+		    buf = buf->b_prev;
+		eap->line2 = buf->b_fnum;
+	    }
+	    break;
+	case ADDR_BUFFERS:
+	    eap->line1 = firstbuf->b_fnum;
+	    eap->line2 = lastbuf->b_fnum;
+	    break;
+	case ADDR_WINDOWS:
+	    eap->line2 = LAST_WIN_NR;
+	    break;
+	case ADDR_TABS:
+	    eap->line2 = LAST_TAB_NR;
+	    break;
+	case ADDR_TABS_RELATIVE:
+	    eap->line2 = 1;
+	    break;
+	case ADDR_ARGUMENTS:
+	    if (ARGCOUNT == 0)
+		eap->line1 = eap->line2 = 0;
+	    else
+		eap->line2 = ARGCOUNT;
+	    break;
+	case ADDR_QUICKFIX_VALID:
+#ifdef FEAT_QUICKFIX
+	    eap->line2 = qf_get_valid_size(eap);
+	    if (eap->line2 == 0)
+		eap->line2 = 1;
+#endif
+	    break;
+	case ADDR_NONE:
+	case ADDR_UNSIGNED:
+	case ADDR_QUICKFIX:
+	    iemsg(_("INTERNAL: Cannot use EX_DFLALL with ADDR_NONE, ADDR_UNSIGNED or ADDR_QUICKFIX"));
+	    break;
+    }
+}
+
+
 /*
  * Get flags from an Ex command argument.
  */
diff --git a/src/if_cscope.c b/src/if_cscope.c
index 0e6f5ae30f..c027c71b48 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -2243,7 +2243,7 @@ cs_release_csp(int i, int freefnpp)
 	    waitpid_errno = errno;
 	    if (pid != 0)
 		break;  // break unless the process is still running
-	    mch_delay(50L, FALSE); // sleep 50 ms
+	    mch_delay(50L, 0); // sleep 50 ms
 	}
 # endif
 	/*
@@ -2278,7 +2278,7 @@ cs_release_csp(int i, int freefnpp)
 			alive = FALSE; // cscope process no longer exists
 			break;
 		    }
-		    mch_delay(50L, FALSE); // sleep 50ms
+		    mch_delay(50L, 0); // sleep 50 ms
 		}
 	    }
 	    if (alive)
diff --git a/src/normal.c b/src/normal.c
index d006642164..ca863675e5 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -3656,8 +3656,10 @@ nv_ident(cmdarg_T *cap)
 	    {
 		if (g_cmd)
 		    STRCPY(buf, "tj ");
+		else if (cap->count0 == 0)
+		    STRCPY(buf, "ta ");
 		else
-		    sprintf((char *)buf, "%ldta ", cap->count0);
+		    sprintf((char *)buf, ":%ldta ", cap->count0);
 	    }
     }
 
diff --git a/src/os_amiga.c b/src/os_amiga.c
index 850c26acda..91c13e7d29 100644
--- a/src/os_amiga.c
+++ b/src/os_amiga.c
@@ -222,10 +222,10 @@ mch_avail_mem(int special)
 
 /*
  * Waits a specified amount of time, or until input arrives if
- * ignoreinput is FALSE.
+ * flags does not have MCH_DELAY_IGNOREINPUT.
  */
     void
-mch_delay(long msec, int ignoreinput)
+mch_delay(long msec, int flags)
 {
 #ifndef LATTICE		// SAS declares void Delay(ULONG)
     void	    Delay(long);
@@ -233,7 +233,7 @@ mch_delay(long msec, int ignoreinput)
 
     if (msec > 0)
     {
-	if (ignoreinput)
+	if (flags & MCH_DELAY_IGNOREINPUT)
 	    Delay(msec / 20L);	    // Delay works with 20 msec intervals
 	else
 	    WaitForChar(raw_in, msec * 1000L);
diff --git a/src/os_unix.c b/src/os_unix.c
index 4ceab10d99..e84f53920a 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -577,15 +577,19 @@ mch_total_mem(int special UNUSED)
 }
 #endif
 
+/*
+ * "flags": MCH_DELAY_IGNOREINPUT - don't read input
+ *	    MCH_DELAY_SETTMODE - use settmode() even for short delays
+ */
     void
-mch_delay(long msec, int ignoreinput)
+mch_delay(long msec, int flags)
 {
     tmode_T	old_tmode;
 #ifdef FEAT_MZSCHEME
     long	total = msec; // remember original value
 #endif
 
-    if (ignoreinput)
+    if (flags & MCH_DELAY_IGNOREINPUT)
     {
 	// Go to cooked mode without echo, to allow SIGINT interrupting us
 	// here.  But we don't want QUIT to kill us (CTRL-\ used in a
@@ -593,7 +597,8 @@ mch_delay(long msec, int ignoreinput)
 	// Only do this if sleeping for more than half a second.
 	in_mch_delay = TRUE;
 	old_tmode = mch_cur_tmode;
-	if (mch_cur_tmode == TMODE_RAW && msec > 500)
+	if (mch_cur_tmode == TMODE_RAW
+			       && (msec > 500 || (flags & MCH_DELAY_SETTMODE)))
 	    settmode(TMODE_SLEEP);
 
 	/*
@@ -636,10 +641,8 @@ mch_delay(long msec, int ignoreinput)
 
 	    tv.tv_sec = msec / 1000;
 	    tv.tv_usec = (msec % 1000) * 1000;
-	    /*
-	     * NOTE: Solaris 2.6 has a bug that makes select() hang here.  Get
-	     * a patch from Sun to fix this.  Reported by Gunnar Pedersen.
-	     */
+	    // NOTE: Solaris 2.6 has a bug that makes select() hang here.  Get
+	    // a patch from Sun to fix this.  Reported by Gunnar Pedersen.
 	    select(0, NULL, NULL, NULL, &tv);
 	}
 #  endif // HAVE_SELECT
@@ -650,7 +653,7 @@ mch_delay(long msec, int ignoreinput)
 	while (total > 0);
 #endif
 
-	if (msec > 500)
+	if (msec > 500 || (flags & MCH_DELAY_SETTMODE))
 	    settmode(old_tmode);
 	in_mch_delay = FALSE;
     }
@@ -1284,7 +1287,7 @@ mch_suspend(void)
 	long wait_time;
 
 	for (wait_time = 0; !sigcont_received && wait_time <= 3L; wait_time++)
-	    mch_delay(wait_time, FALSE);
+	    mch_delay(wait_time, 0);
     }
 # endif
     in_mch_suspend = FALSE;
@@ -4176,7 +4179,7 @@ wait4pid(pid_t child, waitstatus *status)
 	if (wait_pid == 0)
 	{
 	    // Wait for 1 to 10 msec before trying again.
-	    mch_delay(delay_msec, TRUE);
+	    mch_delay(delay_msec, MCH_DELAY_IGNOREINPUT | MCH_DELAY_SETTMODE);
 	    if (++delay_msec > 10)
 		delay_msec = 10;
 	    continue;
@@ -5284,6 +5287,9 @@ finished:
 	    {
 		long delay_msec = 1;
 
+		out_str(T_CTE);	// possibly disables modifyOtherKeys, so that
+				// the system can recognize CTRL-C
+
 		/*
 		 * Similar to the loop above, but only handle X events, no
 		 * I/O.
@@ -5317,11 +5323,14 @@ finished:
 		    clip_update();
 
 		    // Wait for 1 to 10 msec. 1 is faster but gives the child
-		    // less time.
-		    mch_delay(delay_msec, TRUE);
+		    // less time, gradually wait longer.
+		    mch_delay(delay_msec,
+				   MCH_DELAY_IGNOREINPUT | MCH_DELAY_SETTMODE);
 		    if (++delay_msec > 10)
 			delay_msec = 10;
 		}
+
+		out_str(T_CTI);	// possibly enables modifyOtherKeys again
 	    }
 # endif
 
@@ -6732,7 +6741,7 @@ mch_expand_wildcards(
     // When running in the background, give it some time to create the temp
     // file, but don't wait for it to finish.
     if (ampersand)
-	mch_delay(10L, TRUE);
+	mch_delay(10L, MCH_DELAY_IGNOREINPUT);
 
     extra_shell_arg = NULL;		// cleanup
     show_shell_mess = TRUE;
diff --git a/src/os_win32.c b/src/os_win32.c
index 43ad1026d5..96af44364b 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -6739,7 +6739,7 @@ notsgr:
     void
 mch_delay(
     long    msec,
-    int	    ignoreinput UNUSED)
+    int	    flags UNUSED)
 {
 #if defined(FEAT_GUI_MSWIN) && !defined(VIMDLL)
     Sleep((int)msec);	    // never wait for input
@@ -6751,7 +6751,7 @@ mch_delay(
 	return;
     }
 # endif
-    if (ignoreinput)
+    if (flags & MCH_DELAY_IGNOREINPUT)
 # ifdef FEAT_MZSCHEME
 	if (mzthreads_allowed() && p_mzq > 0 && msec > p_mzq)
 	{
diff --git a/src/proto/ex_docmd.pro b/src/proto/ex_docmd.pro
index 20bb85a40f..05c1a85b59 100644
--- a/src/proto/ex_docmd.pro
+++ b/src/proto/ex_docmd.pro
@@ -10,6 +10,7 @@ int parse_command_modifiers(exarg_T *eap, char **errormsg, int skip_only);
 void undo_cmdmod(exarg_T *eap, int save_msg_scroll);
 int parse_cmd_address(exarg_T *eap, char **errormsg, int silent);
 int checkforcmd(char_u **pp, char *cmd, int len);
+char_u *skip_option_env_lead(char_u *start);
 char_u *find_ex_command(exarg_T *eap, int *full, void *(*lookup)(char_u *, size_t, cctx_T *), cctx_T *cctx);
 int modifier_len(char_u *cmd);
 int cmd_exists(char_u *name);
diff --git a/src/proto/os_amiga.pro b/src/proto/os_amiga.pro
index b2ad9c3b55..abebae154f 100644
--- a/src/proto/os_amiga.pro
+++ b/src/proto/os_amiga.pro
@@ -5,7 +5,7 @@ void mch_write(char_u *p, int len);
 int mch_inchar(char_u *buf, int maxlen, long time, int tb_change_cnt);
 int mch_char_avail(void);
 long_u mch_avail_mem(int special);
-void mch_delay(long msec, int ignoreinput);
+void mch_delay(long msec, int flags);
 void mch_suspend(void);
 void mch_init(void);
 int mch_check_win(int argc, char **argv);
diff --git a/src/proto/os_unix.pro b/src/proto/os_unix.pro
index cb84994429..ee22b4a422 100644
--- a/src/proto/os_unix.pro
+++ b/src/proto/os_unix.pro
@@ -5,7 +5,7 @@ int mch_inchar(char_u *buf, int maxlen, long wtime, int tb_change_cnt);
 int mch_char_avail(void);
 int mch_check_messages(void);
 long_u mch_total_mem(int special);
-void mch_delay(long msec, int ignoreinput);
+void mch_delay(long msec, int flags);
 int mch_stackcheck(char *p);
 void mch_suspend(void);
 void mch_init(void);
diff --git a/src/proto/os_win32.pro b/src/proto/os_win32.pro
index 85c09c0ba1..18c81273e1 100644
--- a/src/proto/os_win32.pro
+++ b/src/proto/os_win32.pro
@@ -53,7 +53,7 @@ int mch_signal_job(job_T *job, char_u *how);
 void mch_clear_job(job_T *job);
 void mch_set_normal_colors(void);
 void mch_write(char_u *s, int len);
-void mch_delay(long msec, int ignoreinput);
+void mch_delay(long msec, int flags);
 int mch_remove(char_u *name);
 void mch_breakcheck(int force);
 long_u mch_total_mem(int special);
diff --git a/src/screen.c b/src/screen.c
index 88cdf8cf97..c1f76a3275 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -465,7 +465,8 @@ screen_line(
     // double-wide character. Clear the left half to avoid it getting the popup
     // window background color.
     if (coloff > 0 && ScreenLines[off_to] == 0
-					     && ScreenLinesUC[off_to - 1] != 0)
+		   && ScreenLinesUC[off_to - 1] != 0
+		   && (*mb_char2cells)(ScreenLinesUC[off_to - 1]) > 1)
     {
 	ScreenLines[off_to - 1] = ' ';
 	ScreenLinesUC[off_to - 1] = 0;
diff --git a/src/spell.h b/src/spell.h
index b444145be3..7e4f813b46 100644
--- a/src/spell.h
+++ b/src/spell.h
@@ -66,6 +66,7 @@ struct slang_S
     int		sl_add;		// TRUE if it's a .add file.
 
     char_u	*sl_fbyts;	// case-folded word bytes
+    long	sl_fbyts_len;	// length of sl_fbyts
     idx_T	*sl_fidxs;	// case-folded word indexes
     char_u	*sl_kbyts;	// keep-case word bytes
     idx_T	*sl_kidxs;	// keep-case word indexes
diff --git a/src/spellfile.c b/src/spellfile.c
index 957be097a6..6aeac86b85 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -315,7 +315,7 @@ static int read_compound(FILE *fd, slang_T *slang, int len);
 static int set_sofo(slang_T *lp, char_u *from, char_u *to);
 static void set_sal_first(slang_T *lp);
 static int *mb_str2wide(char_u *s);
-static int spell_read_tree(FILE *fd, char_u **bytsp, idx_T **idxsp, int prefixtree, int prefixcnt);
+static int spell_read_tree(FILE *fd, char_u **bytsp, long *bytsp_len, idx_T **idxsp, int prefixtree, int prefixcnt);
 static idx_T read_tree_node(FILE *fd, char_u *byts, idx_T *idxs, int maxidx, idx_T startidx, int prefixtree, int maxprefcondnr);
 static void set_spell_charflags(char_u *flags, int cnt, char_u *upp);
 static int set_spell_chartab(char_u *fol, char_u *low, char_u *upp);
@@ -553,17 +553,18 @@ truncerr:
     }
 
     // <LWORDTREE>
-    res = spell_read_tree(fd, &lp->sl_fbyts, &lp->sl_fidxs, FALSE, 0);
+    res = spell_read_tree(fd, &lp->sl_fbyts, &lp->sl_fbyts_len,
+						      &lp->sl_fidxs, FALSE, 0);
     if (res != 0)
 	goto someerror;
 
     // <KWORDTREE>
-    res = spell_read_tree(fd, &lp->sl_kbyts, &lp->sl_kidxs, FALSE, 0);
+    res = spell_read_tree(fd, &lp->sl_kbyts, NULL, &lp->sl_kidxs, FALSE, 0);
     if (res != 0)
 	goto someerror;
 
     // <PREFIXTREE>
-    res = spell_read_tree(fd, &lp->sl_pbyts, &lp->sl_pidxs, TRUE,
+    res = spell_read_tree(fd, &lp->sl_pbyts, NULL, &lp->sl_pidxs, TRUE,
 							    lp->sl_prefixcnt);
     if (res != 0)
 	goto someerror;
@@ -737,7 +738,7 @@ suggest_load_files(void)
 	     * <SUGWORDTREE>: <wordtree>
 	     * Read the trie with the soundfolded words.
 	     */
-	    if (spell_read_tree(fd, &slang->sl_sbyts, &slang->sl_sidxs,
+	    if (spell_read_tree(fd, &slang->sl_sbyts, NULL, &slang->sl_sidxs,
 							       FALSE, 0) != 0)
 	    {
 someerror:
@@ -1572,6 +1573,7 @@ mb_str2wide(char_u *s)
 spell_read_tree(
     FILE	*fd,
     char_u	**bytsp,
+    long	*bytsp_len,
     idx_T	**idxsp,
     int		prefixtree,	// TRUE for the prefix tree
     int		prefixcnt)	// when "prefixtree" is TRUE: prefix count
@@ -1596,6 +1598,8 @@ spell_read_tree(
 	if (bp == NULL)
 	    return SP_OTHERERROR;
 	*bytsp = bp;
+	if (bytsp_len != NULL)
+	    *bytsp_len = len;
 
 	// Allocate the index array.
 	ip = lalloc_clear(len * sizeof(int), TRUE);
@@ -5609,8 +5613,8 @@ sug_filltree(spellinfo_T *spin, slang_T *slang)
 		spin->si_blocks_cnt = 0;
 
 		// Skip over any other NUL bytes (same word with different
-		// flags).
-		while (byts[n + 1] == 0)
+		// flags).  But don't go over the end.
+		while (n + 1 < slang->sl_fbyts_len && byts[n + 1] == 0)
 		{
 		    ++n;
 		    ++curi[depth];
diff --git a/src/term.c b/src/term.c
index 1a505794ee..b99c69c946 100644
--- a/src/term.c
+++ b/src/term.c
@@ -3604,7 +3604,7 @@ stoptermcap(void)
 	    {
 # ifdef UNIX
 		// Give the terminal a chance to respond.
-		mch_delay(100L, FALSE);
+		mch_delay(100L, 0);
 # endif
 # ifdef TCIFLUSH
 		// Discard data received but not read.
diff --git a/src/testdir/Make_dos.mak b/src/testdir/Make_dos.mak
index ba728df9eb..89563848ec 100644
--- a/src/testdir/Make_dos.mak
+++ b/src/testdir/Make_dos.mak
@@ -117,7 +117,7 @@ $(TEST_OUTFILES): $(DOSTMP)\$(*B).in
 # Limitation: Only works with the +eval feature.
 
 newtests: newtestssilent
-	@if exist messages (findstr "SKIPPED FAILED" messages > nul) && type messages
+	@if exist messages type messages
 
 newtestssilent: $(NEW_TESTS_RES)
 
diff --git a/src/testdir/Make_ming.mak b/src/testdir/Make_ming.mak
index 00c9e1087a..f9dcfc86e0 100644
--- a/src/testdir/Make_ming.mak
+++ b/src/testdir/Make_ming.mak
@@ -129,7 +129,7 @@ $(DOSTMP)/%.in : %.in
 # Limitation: Only works with the +eval feature.
 
 newtests: newtestssilent
-	@if exist messages (findstr "SKIPPED FAILED" messages > nul) && type messages
+	@if exist messages type messages
 
 newtestssilent: $(NEW_TESTS_RES)
 
diff --git a/src/testdir/Makefile b/src/testdir/Makefile
index 7033d1e46e..2fb329aa1c 100644
--- a/src/testdir/Makefile
+++ b/src/testdir/Makefile
@@ -126,7 +126,7 @@ tinytests: $(SCRIPTS_TINY_OUT)
 RUN_VIMTEST = VIMRUNTIME=$(SCRIPTSOURCE) $(VALGRIND) $(VIMPROG) -f $(GUI_FLAG) -u unix.vim
 
 newtests: newtestssilent
-	@/bin/sh -c "if test -f messages && grep -q 'SKIPPED\|FAILED' messages; then cat messages; fi"
+	@/bin/sh -c "if test -f messages; then cat messages; fi"
 
 newtestssilent: $(NEW_TESTS_RES)
 
diff --git a/src/testdir/test_eval_stuff.vim b/src/testdir/test_eval_stuff.vim
index 02e7e14fd7..1490ffbc57 100644
--- a/src/testdir/test_eval_stuff.vim
+++ b/src/testdir/test_eval_stuff.vim
@@ -135,6 +135,12 @@ func Test_string_concatenation()
   let a = 'a'
   let a..=b
   call assert_equal('ab', a)
+
+  if has('float')
+    let a = 'A'
+    let b = 1.234
+    call assert_fails('echo a .. b', 'E806:')
+  endif
 endfunc
 
 " Test fix for issue #4507
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index dc06bd72ec..e15199b786 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -513,6 +513,10 @@ func Test_strpart()
 
   call assert_equal('lép', strpart('éléphant', 2, 4))
   call assert_equal('léphant', strpart('éléphant', 2))
+
+  call assert_equal('é', strpart('éléphant', 0, 1, 1))
+  call assert_equal('ép', strpart('éléphant', 3, 2, v:true))
+  call assert_equal('ó', strpart('cómposed', 1, 1, 1))
 endfunc
 
 func Test_tolower()
diff --git a/src/testdir/test_spellfile.vim b/src/testdir/test_spellfile.vim
index f3578bce2f..ed11ce0af1 100644
--- a/src/testdir/test_spellfile.vim
+++ b/src/testdir/test_spellfile.vim
@@ -410,6 +410,24 @@ func Test_sugfile_format_error()
   call assert_fails("let s = spellsuggest('abc')", 'E782:')
   set nospell spelllang&
 
+  " invalid suggest word count in SUGTABLE
+  set encoding=utf-8
+  call writefile(0z56494D7375670100000000000000440000000022, sugfile)
+  set runtimepath=./Xtest
+  set spelllang=Xtest
+  set spell
+  call assert_fails("let s = spellsuggest('abc')", 'E782:')
+  set nospell spelllang&
+
+  " missing sugline in SUGTABLE
+  set encoding=utf-8
+  call writefile(0z56494D7375670100000000000000440000000000000005, sugfile)
+  set runtimepath=./Xtest
+  set spelllang=Xtest
+  set spell
+  call assert_fails("let s = spellsuggest('abc')", 'E782:')
+  set nospell spelllang&
+
   let &rtp = save_rtp
   call delete('Xtest', 'rf')
 endfunc
@@ -510,6 +528,197 @@ func Test_mkspell()
   call assert_fails('mkspell en en_US abc_xyz', 'E755:')
 endfunc
 
+" Tests for :mkspell with a .dic and .aff file
+func Test_aff_file_format_error()
+  " FIXME: For some reason, the :mkspell command below doesn't fail on the
+  " MS-Windows CI build. Disable this test on MS-Windows for now.
+  CheckNotMSWindows
+
+  " No word count in .dic file
+  call writefile([], 'Xtest.dic')
+  call writefile([], 'Xtest.aff')
+  call assert_fails('mkspell! Xtest.spl Xtest', 'E760:')
+
+  " create a .dic file for the tests below
+  call writefile(['1', 'work'], 'Xtest.dic')
+
+  " Invalid encoding in .aff file
+  call writefile(['# comment', 'SET Xinvalidencoding'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Conversion in Xtest.aff not supported: from xinvalidencoding', output)
+
+  " Invalid flag in .aff file
+  call writefile(['FLAG xxx'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Invalid value for FLAG in Xtest.aff line 1: xxx', output)
+
+  " set FLAGS after using flag for an affix
+  call writefile(['SFX L Y 1', 'SFX L 0 re [^x]', 'FLAG long'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('FLAG after using flags in Xtest.aff line 3: long', output)
+
+  " INFO in affix file
+  let save_encoding = &encoding
+  call mkdir('Xrtp/spell', 'p')
+  call writefile(['1', 'work'], 'Xrtp/spell/Xtest.dic')
+  call writefile(['NAME klingon', 'VERSION 1.4', 'AUTHOR Spock'],
+        \ 'Xrtp/spell/Xtest.aff')
+  silent mkspell! Xrtp/spell/Xtest.utf-8.spl Xrtp/spell/Xtest
+  let save_rtp = &rtp
+  set runtimepath=./Xrtp
+  set spelllang=Xtest
+  set spell
+  let output = split(execute('spellinfo'), "\n")
+  call assert_equal("NAME klingon", output[1])
+  call assert_equal("VERSION 1.4", output[2])
+  call assert_equal("AUTHOR Spock", output[3])
+  let &rtp = save_rtp
+  call delete('Xrtp', 'rf')
+  set spell& spelllang& spellfile&
+  %bw!
+  " 'encoding' must be set again to clear the spell file in memory
+  let &encoding = save_encoding
+
+  " COMPOUNDFORBIDFLAG flag after PFX in an affix file
+  call writefile(['PFX L Y 1', 'PFX L 0 re x', 'COMPOUNDFLAG c', 'COMPOUNDFORBIDFLAG x'],
+        \ 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Defining COMPOUNDFORBIDFLAG after PFX item may give wrong results in Xtest.aff line 4', output)
+
+  " COMPOUNDPERMITFLAG flag after PFX in an affix file
+  call writefile(['PFX L Y 1', 'PFX L 0 re x', 'COMPOUNDPERMITFLAG c'],
+        \ 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Defining COMPOUNDPERMITFLAG after PFX item may give wrong results in Xtest.aff line 3', output)
+
+  " Wrong COMPOUNDRULES flag value in an affix file
+  call writefile(['COMPOUNDRULES a'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Wrong COMPOUNDRULES value in Xtest.aff line 1: a', output)
+
+  " Wrong COMPOUNDWORDMAX flag value in an affix file
+  call writefile(['COMPOUNDWORDMAX 0'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Wrong COMPOUNDWORDMAX value in Xtest.aff line 1: 0', output)
+
+  " Wrong COMPOUNDMIN flag value in an affix file
+  call writefile(['COMPOUNDMIN 0'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Wrong COMPOUNDMIN value in Xtest.aff line 1: 0', output)
+
+  " Wrong COMPOUNDSYLMAX flag value in an affix file
+  call writefile(['COMPOUNDSYLMAX 0'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Wrong COMPOUNDSYLMAX value in Xtest.aff line 1: 0', output)
+
+  " Wrong CHECKCOMPOUNDPATTERN flag value in an affix file
+  call writefile(['CHECKCOMPOUNDPATTERN 0'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Wrong CHECKCOMPOUNDPATTERN value in Xtest.aff line 1: 0', output)
+
+  " Duplicate affix entry in an affix file
+  call writefile(['PFX L Y 1', 'PFX L 0 re x', 'PFX L Y 1', 'PFX L 0 re x'],
+        \ 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Duplicate affix in Xtest.aff line 3: L', output)
+
+  " Duplicate affix entry in an affix file
+  call writefile(['PFX L Y 1', 'PFX L Y 1'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Unrecognized or duplicate item in Xtest.aff line 2: PFX', output)
+
+  " Different combining flags in an affix file
+  call writefile(['PFX L Y 1', 'PFX L 0 re x', 'PFX L N 1'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Different combining flag in continued affix block in Xtest.aff line 3', output)
+
+  " Try to reuse a affix used for BAD flag
+  call writefile(['BAD x', 'PFX x Y 1', 'PFX x 0 re x'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Affix also used for BAD/RARE/KEEPCASE/NEEDAFFIX/NEEDCOMPOUND/NOSUGGEST in Xtest.aff line 2: x', output)
+
+  " Trailing characters in an affix entry
+  call writefile(['PFX L Y 1 Test', 'PFX L 0 re x'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Trailing text in Xtest.aff line 1: Test', output)
+
+  " Trailing characters in an affix entry
+  call writefile(['PFX L Y 1', 'PFX L 0 re x Test'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Trailing text in Xtest.aff line 2: Test', output)
+
+  " Incorrect combine flag in an affix entry
+  call writefile(['PFX L X 1', 'PFX L 0 re x'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Expected Y or N in Xtest.aff line 1: X', output)
+
+  " Invalid count for REP item
+  call writefile(['REP a'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Expected REP(SAL) count in Xtest.aff line 1', output)
+
+  " Trailing characters in REP item
+  call writefile(['REP 1', 'REP f ph test'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Trailing text in Xtest.aff line 2: test', output)
+
+  " Invalid count for MAP item
+  call writefile(['MAP a'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Expected MAP count in Xtest.aff line 1', output)
+
+  " Duplicate character in a MAP item
+  call writefile(['MAP 2', 'MAP xx', 'MAP yy'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Duplicate character in MAP in Xtest.aff line 2', output)
+
+  " Use COMPOUNDSYLMAX without SYLLABLE
+  call writefile(['COMPOUNDSYLMAX 2'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('COMPOUNDSYLMAX used without SYLLABLE', output)
+
+  " Missing SOFOTO
+  call writefile(['SOFOFROM abcdef'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Missing SOFOTO line in Xtest.aff', output)
+
+  " Length of SOFOFROM and SOFOTO differ
+  call writefile(['SOFOFROM abcde', 'SOFOTO ABCD'], 'Xtest.aff')
+  call assert_fails('mkspell! Xtest.spl Xtest', 'E759:')
+
+  " Both SAL and SOFOFROM/SOFOTO items
+  call writefile(['SOFOFROM abcd', 'SOFOTO ABCD', 'SAL CIA X'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Both SAL and SOFO lines in Xtest.aff', output)
+
+  " use an alphabet flag when FLAG is num
+  call writefile(['FLAG num', 'SFX L Y 1', 'SFX L 0 re [^x]'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Flag is not a number in Xtest.aff line 2: L', output)
+
+  " use number and alphabet flag when FLAG is num
+  call writefile(['FLAG num', 'SFX 4f Y 1', 'SFX 4f 0 re [^x]'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Affix name too long in Xtest.aff line 2: 4f', output)
+
+  " use a single character flag when FLAG is long
+  call writefile(['FLAG long', 'SFX L Y 1', 'SFX L 0 re [^x]'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('Illegal flag in Xtest.aff line 2: L', output)
+
+  " duplicate word in the .dic file
+  call writefile(['2', 'good', 'good', 'good'], 'Xtest.dic')
+  call writefile(['NAME vim'], 'Xtest.aff')
+  let output = execute('mkspell! Xtest.spl Xtest')
+  call assert_match('First duplicate word in Xtest.dic line 3: good', output)
+  call assert_match('2 duplicate word(s) in Xtest.dic', output)
+
+  call delete('Xtest.dic')
+  call delete('Xtest.aff')
+  call delete('Xtest.spl')
+  call delete('Xtest.sug')
+endfunc
+
 func Test_spell_add_word()
   set spellfile=
   call assert_fails('spellgood abc', 'E764:')
@@ -524,4 +733,36 @@ func Test_spell_add_word()
   %bw!
 endfunc
 
+" When 'spellfile' is not set, adding a new good word will automatically set
+" the 'spellfile'
+func Test_init_spellfile()
+  let save_rtp = &rtp
+  let save_encoding = &encoding
+  call mkdir('Xrtp/spell', 'p')
+  call writefile(['vim'], 'Xrtp/spell/Xtest.dic')
+  silent mkspell Xrtp/spell/Xtest.utf-8.spl Xrtp/spell/Xtest.dic
+  set runtimepath=./Xrtp
+  set spelllang=Xtest
+  set spell
+  silent spellgood abc
+  call assert_equal('./Xrtp/spell/Xtest.utf-8.add', &spellfile)
+  call assert_equal(['abc'], readfile('Xrtp/spell/Xtest.utf-8.add'))
+  call assert_true(filereadable('Xrtp/spell/Xtest.utf-8.spl'))
+  set spell& spelllang& spellfile&
+  call delete('Xrtp', 'rf')
+  let &encoding = save_encoding
+  let &rtp = save_rtp
+  %bw!
+endfunc
+
+" Test for the 'mkspellmem' option
+func Test_mkspellmem_opt()
+  call assert_fails('set mkspellmem=1000', 'E474:')
+  call assert_fails('set mkspellmem=1000,', 'E474:')
+  call assert_fails('set mkspellmem=1000,50', 'E474:')
+  call assert_fails('set mkspellmem=1000,50,', 'E474:')
+  call assert_fails('set mkspellmem=1000,50,10,', 'E474:')
+  call assert_fails('set mkspellmem=1000,50,0', 'E474:')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_vim9_cmd.vim b/src/testdir/test_vim9_cmd.vim
index 9f4231a9a3..9372d90952 100644
--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -295,5 +295,25 @@ def Test_map_command()
   CheckScriptSuccess(['vim9script'] + lines)
 enddef
 
+def Test_normal_command()
+  new
+  setline(1, 'doesnotexist')
+  let caught = 0
+  try
+    exe "norm! \<C-]>"
+  catch /E433/
+    caught = 2
+  endtry
+  assert_equal(2, caught)
+
+  try
+    exe "norm! 3\<C-]>"
+  catch /E433/
+    caught = 3
+  endtry
+  assert_equal(3, caught)
+  bwipe!
+enddef
+
 
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 4ff0fd7e25..a7d8d87f3c 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -43,6 +43,9 @@ def Test_expr1()
   var = 0
   assert_equal('two', var ? 'one' : 'two')
 
+  # with constant condition expression is not evaluated 
+  assert_equal('one', 1 ? 'one' : xxx)
+
   let Some: func = function('len')
   let Other: func = function('winnr')
   let Res: func = g:atrue ? Some : Other
@@ -139,7 +142,6 @@ enddef
 
 func Test_expr1_fails()
   call CheckDefFailure(["let x = 1 ? 'one'"], "Missing ':' after '?'", 1)
-  call CheckDefFailure(["let x = 1 ? 'one' : xxx"], "E1001:", 1)
 
   let msg = "white space required before and after '?'"
   call CheckDefFailure(["let x = 1? 'one' : 'two'"], msg, 1)
@@ -1668,6 +1670,17 @@ def Test_expr7_lambda_vim9script()
   CheckScriptSuccess(lines)
 enddef
 
+def Test_epxr7_funcref()
+  let lines =<< trim END
+    def RetNumber(): number
+      return 123
+    enddef
+    let FuncRef = RetNumber
+    assert_equal(123, FuncRef())
+  END
+  CheckDefAndScriptSuccess(lines)
+enddef
+
 def Test_expr7_dict()
   # dictionary
   assert_equal(g:dict_empty, {})
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index 5a251473cd..054fe4cbfc 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -15,6 +15,18 @@ def Test_range_only()
   setline(1, ['blah', 'Blah'])
   :/Blah/
   assert_equal(2, getcurpos()[1])
+  bwipe!
+
+  # without range commands use current line
+  new
+  setline(1, ['one', 'two', 'three'])
+  :2
+  print
+  assert_equal('two', Screenline(&lines))
+  :3
+  list
+  assert_equal('three$', Screenline(&lines))
+  bwipe!
 enddef
 
 let s:appendToMe = 'xxx'
@@ -110,12 +122,21 @@ def Test_assignment()
   endif
 
   lines =<< trim END
-    vim9script
     &ts = 6
     &ts += 3
     assert_equal(9, &ts)
+
+    &l:ts = 6
+    assert_equal(6, &ts)
+    &l:ts += 2
+    assert_equal(8, &ts)
+
+    &g:ts = 6
+    assert_equal(6, &g:ts)
+    &g:ts += 2
+    assert_equal(8, &g:ts)
   END
-  CheckScriptSuccess(lines)
+  CheckDefAndScriptSuccess(lines)
 
   CheckDefFailure(['&notex += 3'], 'E113:')
   CheckDefFailure(['&ts ..= "xxx"'], 'E1019:')
@@ -163,19 +184,15 @@ def Test_assignment()
   call CheckDefFailure(['$SOME_ENV_VAR += "more"'], 'E1051:')
   call CheckDefFailure(['$SOME_ENV_VAR += 123'], 'E1012:')
 
-  @a = 'areg'
-  @a ..= 'add'
-  assert_equal('aregadd', @a)
-  call CheckDefFailure(['@a += "more"'], 'E1051:')
-  call CheckDefFailure(['@a += 123'], 'E1012:')
-
   lines =<< trim END
-    vim9script
     @c = 'areg'
     @c ..= 'add'
     assert_equal('aregadd', @c)
   END
-  call CheckScriptSuccess(lines)
+  CheckDefAndScriptSuccess(lines)
+
+  call CheckDefFailure(['@a += "more"'], 'E1051:')
+  call CheckDefFailure(['@a += 123'], 'E1012:')
 
   v:errmsg = 'none'
   v:errmsg ..= 'again'
@@ -608,6 +625,13 @@ def Test_unlet()
   assert_false(exists('g:somevar'))
   unlet! g:somevar
 
+  # also works for script-local variable in legacy Vim script
+  s:somevar = 'legacy'
+  assert_true(exists('s:somevar'))
+  unlet s:somevar
+  assert_false(exists('s:somevar'))
+  unlet! s:somevar
+
   call CheckScriptFailure([
         'vim9script',
         'let svar = 123',
@@ -1660,8 +1684,9 @@ def Test_vim9script_funcref()
   delete('Xscript.vim')
 enddef
 
-" Check that when searcing for "FilterFunc" it doesn't find the import in the
-" script where FastFilter() is called from.
+" Check that when searching for "FilterFunc" it finds the import in the
+" script where FastFilter() is called from, both as a string and as a direct
+" function reference.
 def Test_vim9script_funcref_other_script()
   let filterLines =<< trim END
     vim9script
@@ -1671,22 +1696,26 @@ def Test_vim9script_funcref_other_script()
     export def FastFilter(): list<number>
       return range(10)->filter('FilterFunc')
     enddef
+    export def FastFilterDirect(): list<number>
+      return range(10)->filter(FilterFunc)
+    enddef
   END
   writefile(filterLines, 'Xfilter.vim')
 
   let lines =<< trim END
     vim9script
-    import {FilterFunc, FastFilter} from './Xfilter.vim'
+    import {FilterFunc, FastFilter, FastFilterDirect} from './Xfilter.vim'
     def Test()
       let x: list<number> = FastFilter()
     enddef
     Test()
+    def TestDirect()
+      let x: list<number> = FastFilterDirect()
+    enddef
+    TestDirect()
   END
-  writefile(lines, 'Ximport.vim')
-  assert_fails('source Ximport.vim', 'E121:')
-
+  CheckScriptSuccess(lines)
   delete('Xfilter.vim')
-  delete('Ximport.vim')
 enddef
 
 def Test_vim9script_reload_delfunc()
@@ -2093,6 +2122,14 @@ def Test_if_const_expr()
     res = true
   endif
   assert_equal(false, res)
+
+  # with constant "false" expression may be invalid so long as the syntax is OK
+  if false | eval 0 | endif
+  if false | eval burp + 234 | endif
+  if false | echo burp 234 'asd' | endif
+  if false
+    burp
+  endif
 enddef
 
 def Test_if_const_expr_fails()
@@ -2152,8 +2189,9 @@ def Test_execute_cmd()
   echomsg [1, 2, 3] #{a: 1, b: 2}
   assert_match('^\[1, 2, 3\] {''a'': 1, ''b'': 2}$', Screenline(&lines))
 
-  call CheckDefFailure(['execute xxx'], 'E1001:')
-  call CheckDefFailure(['execute "cmd"# comment'], 'E488:')
+  call CheckDefFailure(['execute xxx'], 'E1001:', 1)
+  call CheckDefExecFailure(['execute "tabnext " .. 8'], 'E475:', 1)
+  call CheckDefFailure(['execute "cmd"# comment'], 'E488:', 1)
 enddef
 
 def Test_execute_cmd_vimscript()
diff --git a/src/testdir/vim9.vim b/src/testdir/vim9.vim
index 2f92cf954e..7fbe4a5ed3 100644
--- a/src/testdir/vim9.vim
+++ b/src/testdir/vim9.vim
@@ -41,6 +41,11 @@ def CheckScriptSuccess(lines: list<string>)
   delete('Xdef')
 enddef
 
+def CheckDefAndScriptSuccess(lines: list<string>)
+  CheckDefSuccess(lines)
+  CheckScriptSuccess(['vim9script'] + lines)
+enddef
+
 " Check that a command fails both when used in a :def function and when used
 " in Vim9 script.
 def CheckScriptAndDefFailure(lines: list<string>, error: string, lnum = -3)
diff --git a/src/ui.c b/src/ui.c
index 68c59c6eaf..6efb1a2f33 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -548,7 +548,7 @@ ui_delay(long msec_arg, int ignoreinput)
 	if (gui.in_use)
 	    gui_macvim_force_flush();
 #endif
-	mch_delay(msec, ignoreinput);
+	mch_delay(msec, ignoreinput ? MCH_DELAY_IGNOREINPUT : 0);
     }
 }
 
diff --git a/src/version.c b/src/version.c
index c7206faef4..918b6f6554 100644
--- a/src/version.c
+++ b/src/version.c
@@ -769,6 +769,44 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1531,
+/**/
+    1530,
+/**/
+    1529,
+/**/
+    1528,
+/**/
+    1527,
+/**/
+    1526,
+/**/
+    1525,
+/**/
+    1524,
+/**/
+    1523,
+/**/
+    1522,
+/**/
+    1521,
+/**/
+    1520,
+/**/
+    1519,
+/**/
+    1518,
+/**/
+    1517,
+/**/
+    1516,
+/**/
+    1515,
+/**/
+    1514,
+/**/
+    1513,
 /**/
     1512,
 /**/
diff --git a/src/vim.h b/src/vim.h
index edccc9c1d4..e260673552 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2679,4 +2679,8 @@ long elapsed(DWORD start_tick);
 #define READDIR_SORT_IC		2  // sort ignoring case (strcasecmp)
 #define READDIR_SORT_COLLATE	3  // sort according to collation (strcoll)
 
+// Flags for mch_delay.
+#define MCH_DELAY_IGNOREINPUT	1
+#define MCH_DELAY_SETTMODE	2
+
 #endif // VIM__H
diff --git a/src/vim9compile.c b/src/vim9compile.c
index e4b7d44adb..5e4bfdb76c 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -258,6 +258,15 @@ lookup_arg(
     return FAIL;
 }
 
+/*
+ * Returnd TRUE if the script context is Vim9 script.
+ */
+    static int
+script_is_vim9()
+{
+    return SCRIPT_ITEM(current_sctx.sc_sid)->sn_version == SCRIPT_VERSION_VIM9;
+}
+
 /*
  * Lookup a variable in the current script.
  * If "vim9script" is TRUE the script must be Vim9 script.  Used for "var"
@@ -271,8 +280,7 @@ lookup_script(char_u *name, size_t len, int vim9script)
     hashtab_T	    *ht = &SCRIPT_VARS(current_sctx.sc_sid);
     dictitem_T	    *di;
 
-    if (vim9script && SCRIPT_ITEM(current_sctx.sc_sid)->sn_version
-							!= SCRIPT_VERSION_VIM9)
+    if (vim9script && !script_is_vim9())
 	return FAIL;
     cc = name[len];
     name[len] = NUL;
@@ -4006,6 +4014,13 @@ compile_expr1(char_u **arg,  cctx_T *cctx, ppconst_T *ppconst)
     int		ppconst_used = ppconst->pp_used;
     char_u	*next;
 
+    // Ignore all kinds of errors when not producing code.
+    if (cctx->ctx_skip == SKIP_YES)
+    {
+	skip_expr(arg);
+	return OK;
+    }
+
     // Evaluate the first expression.
     if (compile_expr2(arg, cctx, ppconst) == FAIL)
 	return FAIL;
@@ -4256,7 +4271,7 @@ compile_nested_function(exarg_T *eap, cctx_T *cctx)
     ufunc = def_function(eap, lambda_name);
 
     if (ufunc == NULL)
-	return NULL;
+	return eap->skip ? (char_u *)"" : NULL;
     if (ufunc->uf_def_status == UF_TO_BE_COMPILED
 	    && compile_def_function(ufunc, TRUE, cctx) == FAIL)
 	return NULL;
@@ -4542,8 +4557,8 @@ compile_assignment(char_u *arg, exarg_T *eap, cmdidx_T cmdidx, cctx_T *cctx)
 	    p = var_start + 2;
 	else
 	{
-	    p = (*var_start == '&' || *var_start == '$')
-						   ? var_start + 1 : var_start;
+	    // skip over the leading "&", "&l:", "&g:" and "$"
+	    p = skip_option_env_lead(var_start);
 	    p = to_name_end(p, TRUE);
 	}
 
@@ -4587,8 +4602,8 @@ compile_assignment(char_u *arg, exarg_T *eap, cmdidx_T cmdidx, cctx_T *cctx)
 		}
 		cc = *p;
 		*p = NUL;
-		opt_type = get_option_value(var_start + 1, &numval,
-							      NULL, opt_flags);
+		opt_type = get_option_value(skip_option_env_lead(var_start),
+						     &numval, NULL, opt_flags);
 		*p = cc;
 		if (opt_type == -3)
 		{
@@ -5123,7 +5138,8 @@ compile_assignment(char_u *arg, exarg_T *eap, cmdidx_T cmdidx, cctx_T *cctx)
 	    switch (dest)
 	    {
 		case dest_option:
-		    generate_STOREOPT(cctx, name + 1, opt_flags);
+		    generate_STOREOPT(cctx, skip_option_env_lead(name),
+								    opt_flags);
 		    break;
 		case dest_global:
 		    // include g: with the name, easier to execute that way
@@ -5234,6 +5250,9 @@ check_vim9_unlet(char_u *name)
 {
     if (name[1] != ':' || vim_strchr((char_u *)"gwtb", *name) == NULL)
     {
+	// "unlet s:var" is allowed in legacy script.
+	if (*name == 's' && !script_is_vim9())
+	    return OK;
 	semsg(_(e_cannot_unlet_str), name);
 	return FAIL;
     }
@@ -5500,6 +5519,7 @@ compile_elseif(char_u *arg, cctx_T *cctx)
     isn_T	*isn;
     scope_T	*scope = cctx->ctx_scope;
     ppconst_T	ppconst;
+    skip_T	save_skip = cctx->ctx_skip;
 
     if (scope == NULL || scope->se_type != IF_SCOPE)
     {
@@ -5522,11 +5542,14 @@ compile_elseif(char_u *arg, cctx_T *cctx)
 
     // compile "expr"; if we know it evaluates to FALSE skip the block
     CLEAR_FIELD(ppconst);
+    if (cctx->ctx_skip == SKIP_YES)
+	cctx->ctx_skip = SKIP_UNKNOWN;
     if (compile_expr1(&p, cctx, &ppconst) == FAIL)
     {
 	clear_ppconst(&ppconst);
 	return NULL;
     }
+    cctx->ctx_skip = save_skip;
     if (scope->se_skip_save == SKIP_YES)
 	clear_ppconst(&ppconst);
     else if (instr->ga_len == instr_count && ppconst.pp_used == 1)
@@ -6712,17 +6735,8 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 
 	p = skipwhite(p);
 
-	if (cctx.ctx_skip == SKIP_YES
-		&& ea.cmdidx != CMD_if
+	if (cctx.ctx_had_return
 		&& ea.cmdidx != CMD_elseif
-		&& ea.cmdidx != CMD_else
-		&& ea.cmdidx != CMD_endif)
-	{
-	    line = (char_u *)"";
-	    continue;
-	}
-
-	if (ea.cmdidx != CMD_elseif
 		&& ea.cmdidx != CMD_else
 		&& ea.cmdidx != CMD_endif
 		&& ea.cmdidx != CMD_endfor
@@ -6731,11 +6745,8 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 		&& ea.cmdidx != CMD_finally
 		&& ea.cmdidx != CMD_endtry)
 	{
-	    if (cctx.ctx_had_return)
-	    {
-		emsg(_(e_unreachable_code_after_return));
-		goto erret;
-	    }
+	    emsg(_(e_unreachable_code_after_return));
+	    goto erret;
 	}
 
 	switch (ea.cmdidx)
@@ -6833,7 +6844,7 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 		    if (compile_expr0(&p, &cctx) == FAIL)
 			goto erret;
 
-		    // drop the return value
+		    // drop the result
 		    generate_instr_drop(&cctx, ISN_DROP, 1);
 
 		    line = skipwhite(p);
@@ -6847,7 +6858,7 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 		    line = compile_mult_expr(p, ea.cmdidx, &cctx);
 		    break;
 
-	    // TODO: other commands with an expression argument
+	    // TODO: any other commands with an expression argument?
 
 	    case CMD_append:
 	    case CMD_change:
@@ -6858,13 +6869,27 @@ compile_def_function(ufunc_T *ufunc, int set_return_type, cctx_T *outer_cctx)
 		    goto erret;
 
 	    case CMD_SIZE:
-		    semsg(_(e_invalid_command_str), ea.cmd);
-		    goto erret;
+		    if (cctx.ctx_skip != SKIP_YES)
+		    {
+			semsg(_(e_invalid_command_str), ea.cmd);
+			goto erret;
+		    }
+		    // We don't check for a next command here.
+		    line = (char_u *)"";
+		    break;
 
 	    default:
-		    // Not recognized, execute with do_cmdline_cmd().
-		    ea.arg = p;
-		    line = compile_exec(line, &ea, &cctx);
+		    if (cctx.ctx_skip == SKIP_YES)
+		    {
+			// We don't check for a next command here.
+			line = (char_u *)"";
+		    }
+		    else
+		    {
+			// Not recognized, execute with do_cmdline_cmd().
+			ea.arg = p;
+			line = compile_exec(line, &ea, &cctx);
+		    }
 		    break;
 	}
 nextline:
diff --git a/src/vim9execute.c b/src/vim9execute.c
index a49f3d7c6f..53a748e971 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1062,7 +1062,10 @@ call_def_function(
 		    if (ga.ga_data != NULL)
 		    {
 			if (iptr->isn_type == ISN_EXECUTE)
+			{
+			    SOURCING_LNUM = iptr->isn_lnum;
 			    do_cmdline_cmd((char_u *)ga.ga_data);
+			}
 			else
 			{
 			    msg_sb_eol();