diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 1de0e40ad1..12d62a6760 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -6239,8 +6239,26 @@ min({expr})	Return the minimum value of all items in {expr}. Example:  >
 mkdir({name} [, {path} [, {prot}]])
 		Create directory {name}.
 
-		If {path} is "p" then intermediate directories are created as
-		necessary.  Otherwise it must be "".
+		If {path} contains "p" then intermediate directories are
+		created as necessary.  Otherwise it must be "".
+
+		If {path} contains "D" then {name} is deleted at the end of
+		the current function, as with: >
+			defer delete({name}, 'd')
+<
+		If {path} contains "R" then {name} is deleted recursively at
+		the end of the current function, as with: >
+			defer delete({name}, 'rf')
+<		Note that when {name} has more than one part and "p" is used
+		some directories may already exist.  Only the first one that
+		is created and what it contains is scheduled to be deleted.
+		E.g. when using: >
+			call mkdir('subdir/tmp/autoload', 'pR')
+<		and "subdir" already exists then "subdir/tmp" will be
+		scheduled for deletion, like with: >
+			defer delete('subdir/tmp', 'rf')
+<		Note that if scheduling the defer fails the directory is not
+		deleted.  This should only happen when out of memory.
 
 		If {prot} is given it is used to set the protection bits of
 		the new directory.  The default is 0o755 (rwxr-xr-x: r/w for
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index c7670d08ca..e79bbba35e 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -940,7 +940,7 @@ au BufNewFile,BufRead *.java,*.jav		setf java
 au BufNewFile,BufRead *.jj,*.jjt		setf javacc
 
 " JavaScript, ECMAScript, ES module script, CommonJS script
-au BufNewFile,BufRead *.js,*.javascript,*.es,*.mjs,*.cjs   setf javascript
+au BufNewFile,BufRead *.js,*.jsm,*.javascript,*.es,*.mjs,*.cjs   setf javascript
 
 " JavaScript with React
 au BufNewFile,BufRead *.jsx			setf javascriptreact
diff --git a/src/charset.c b/src/charset.c
index b26ebb96c7..d26a696c74 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -943,14 +943,13 @@ vim_isprintc_strict(int c)
 init_chartabsize_arg(
 	chartabsize_T	*cts,
 	win_T		*wp,
-	linenr_T	lnum,
+	linenr_T	lnum UNUSED,
 	colnr_T		col,
 	char_u		*line,
 	char_u		*ptr)
 {
     CLEAR_POINTER(cts);
     cts->cts_win = wp;
-    cts->cts_lnum = lnum;
     cts->cts_vcol = col;
     cts->cts_line = line;
     cts->cts_ptr = ptr;
diff --git a/src/dict.c b/src/dict.c
index 874b8231da..fa54c60c41 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -911,13 +911,15 @@ eval_dict(char_u **arg, typval_T *rettv, evalarg_T *evalarg, int literal)
     int		vim9script = in_vim9script();
     int		had_comma;
 
-    // First check if it's not a curly-braces thing: {expr}.
+    // First check if it's not a curly-braces expression: {expr}.
     // Must do this without evaluating, otherwise a function may be called
     // twice.  Unfortunately this means we need to call eval1() twice for the
     // first item.
-    // But {} is an empty Dictionary.
+    // "{}" is an empty Dictionary.
+    // "#{abc}" is never a curly-braces expression.
     if (!vim9script
 	    && *curly_expr != '}'
+	    && !literal
 	    && eval1(&curly_expr, &tv, NULL) == OK
 	    && *skipwhite(curly_expr) == '}')
 	return NOTDONE;
diff --git a/src/eval.c b/src/eval.c
index 5ec5b8ae7b..9891473813 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -263,9 +263,17 @@ eval_expr_typval(typval_T *expr, typval_T *argv, int argc, typval_T *rettv)
 	if (partial->pt_func != NULL
 			  && partial->pt_func->uf_def_status != UF_NOT_COMPILED)
 	{
-	    // FIXME: should create a funccal and link it in current_funccal.
-	    if (call_def_function(partial->pt_func, argc, argv,
-						 partial, NULL, rettv) == FAIL)
+	    funccall_T	*fc = create_funccal(partial->pt_func, rettv);
+	    int		r;
+
+	    if (fc == NULL)
+		return FAIL;
+
+	    // Shortcut to call a compiled function without overhead.
+	    r = call_def_function(partial->pt_func, argc, argv,
+					  DEF_USE_PT_ARGV, partial, fc, rettv);
+	    remove_funccal();
+	    if (r == FAIL)
 		return FAIL;
 	}
 	else
diff --git a/src/filepath.c b/src/filepath.c
index 3094d91270..43216bea23 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -1428,10 +1428,12 @@ f_isabsolutepath(typval_T *argvars, typval_T *rettv)
 /*
  * Create the directory in which "dir" is located, and higher levels when
  * needed.
+ * Set "created" to the full name of the first created directory.  It will be
+ * NULL until that happens.
  * Return OK or FAIL.
  */
     static int
-mkdir_recurse(char_u *dir, int prot)
+mkdir_recurse(char_u *dir, int prot, char_u **created)
 {
     char_u	*p;
     char_u	*updir;
@@ -1449,8 +1451,12 @@ mkdir_recurse(char_u *dir, int prot)
 	return FAIL;
     if (mch_isdir(updir))
 	r = OK;
-    else if (mkdir_recurse(updir, prot) == OK)
+    else if (mkdir_recurse(updir, prot, created) == OK)
+    {
 	r = vim_mkdir_emsg(updir, prot);
+	if (r == OK && created != NULL && *created == NULL)
+	    *created = FullName_save(updir, FALSE);
+    }
     vim_free(updir);
     return r;
 }
@@ -1464,6 +1470,9 @@ f_mkdir(typval_T *argvars, typval_T *rettv)
     char_u	*dir;
     char_u	buf[NUMBUFLEN];
     int		prot = 0755;
+    int		defer = FALSE;
+    int		defer_recurse = FALSE;
+    char_u	*created = NULL;
 
     rettv->vval.v_number = FAIL;
     if (check_restricted() || check_secure())
@@ -1486,13 +1495,21 @@ f_mkdir(typval_T *argvars, typval_T *rettv)
 
     if (argvars[1].v_type != VAR_UNKNOWN)
     {
+	char_u *arg2;
+
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	{
 	    prot = (int)tv_get_number_chk(&argvars[2], NULL);
 	    if (prot == -1)
 		return;
 	}
-	if (STRCMP(tv_get_string(&argvars[1]), "p") == 0)
+	arg2 = tv_get_string(&argvars[1]);
+	defer = vim_strchr(arg2, 'D') != NULL;
+	defer_recurse = vim_strchr(arg2, 'R') != NULL;
+	if ((defer || defer_recurse) && !can_add_defer())
+	    return;
+
+	if (vim_strchr(arg2, 'p') != NULL)
 	{
 	    if (mch_isdir(dir))
 	    {
@@ -1500,10 +1517,33 @@ f_mkdir(typval_T *argvars, typval_T *rettv)
 		rettv->vval.v_number = OK;
 		return;
 	    }
-	    mkdir_recurse(dir, prot);
+	    mkdir_recurse(dir, prot, defer || defer_recurse ? &created : NULL);
 	}
     }
     rettv->vval.v_number = vim_mkdir_emsg(dir, prot);
+
+    // Handle "D" and "R": deferred deletion of the created directory.
+    if (rettv->vval.v_number == OK
+				&& created == NULL && (defer || defer_recurse))
+	created = FullName_save(dir, FALSE);
+    if (created != NULL)
+    {
+	typval_T tv[2];
+
+	tv[0].v_type = VAR_STRING;
+	tv[0].v_lock = 0;
+	tv[0].vval.v_string = created;
+	tv[1].v_type = VAR_STRING;
+	tv[1].v_lock = 0;
+	tv[1].vval.v_string = vim_strsave(
+				       (char_u *)(defer_recurse ? "rf" : "d"));
+	if (tv[0].vval.v_string == NULL || tv[1].vval.v_string == NULL
+		|| add_defer((char_u *)"delete", 2, tv) == FAIL)
+	{
+	    vim_free(tv[0].vval.v_string);
+	    vim_free(tv[1].vval.v_string);
+	}
+    }
 }
 
 /*
@@ -2300,11 +2340,8 @@ f_writefile(typval_T *argvars, typval_T *rettv)
     if (fname == NULL)
 	return;
 
-    if (defer && !in_def_function() && get_current_funccal() == NULL)
-    {
-	semsg(_(e_str_not_inside_function), "defer");
+    if (defer && !can_add_defer())
 	return;
-    }
 
     // Always open the file in binary mode, library functions have a mind of
     // their own about CR-LF conversion.
@@ -2323,7 +2360,7 @@ f_writefile(typval_T *argvars, typval_T *rettv)
 
 	    tv.v_type = VAR_STRING;
 	    tv.v_lock = 0;
-	    tv.vval.v_string = vim_strsave(fname);
+	    tv.vval.v_string = FullName_save(fname, FALSE);
 	    if (tv.vval.v_string == NULL
 		    || add_defer((char_u *)"delete", 1, &tv) == FAIL)
 	    {
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 20b0a5f64e..8ae0cd069b 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -8649,6 +8649,7 @@ test_gui_w32_sendevent(dict_T *args)
 	inputs[0].ki.wVk = vkCode;
 	if (STRICMP(event, "keyup") == 0)
 	    inputs[0].ki.dwFlags = KEYEVENTF_KEYUP;
+	(void)SetForegroundWindow(s_hwnd);
 	SendInput(ARRAYSIZE(inputs), inputs, sizeof(INPUT));
     }
     else
diff --git a/src/proto/userfunc.pro b/src/proto/userfunc.pro
index 4fbbe86c99..e5543f389d 100644
--- a/src/proto/userfunc.pro
+++ b/src/proto/userfunc.pro
@@ -21,6 +21,8 @@ int funcdepth_increment(void);
 void funcdepth_decrement(void);
 int funcdepth_get(void);
 void funcdepth_restore(int depth);
+funccall_T *create_funccal(ufunc_T *fp, typval_T *rettv);
+void remove_funccal(void);
 int check_user_func_argcount(ufunc_T *fp, int argcount);
 int call_user_func_check(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rettv, funcexe_T *funcexe, dict_T *selfdict);
 void save_funccal(funccal_entry_T *entry);
@@ -58,6 +60,7 @@ void func_ptr_unref(ufunc_T *fp);
 void func_ref(char_u *name);
 void func_ptr_ref(ufunc_T *fp);
 void ex_return(exarg_T *eap);
+int can_add_defer(void);
 int add_defer(char_u *name, int argcount_arg, typval_T *argvars);
 void invoke_all_defer(void);
 void ex_call(exarg_T *eap);
diff --git a/src/proto/vim9execute.pro b/src/proto/vim9execute.pro
index bb3d414e7a..b8360c5e65 100644
--- a/src/proto/vim9execute.pro
+++ b/src/proto/vim9execute.pro
@@ -15,7 +15,7 @@ typval_T *lookup_debug_var(char_u *name);
 int may_break_in_function(ufunc_T *ufunc);
 int exe_typval_instr(typval_T *tv, typval_T *rettv);
 char_u *exe_substitute_instr(void);
-int call_def_function(ufunc_T *ufunc, int argc_arg, typval_T *argv, partial_T *partial, funccall_T *funccal, typval_T *rettv);
+int call_def_function(ufunc_T *ufunc, int argc_arg, typval_T *argv, int flags, partial_T *partial, funccall_T *funccal, typval_T *rettv);
 void unwind_def_callstack(ectx_T *ectx);
 void may_invoke_defer_funcs(ectx_T *ectx);
 void set_context_in_disassemble_cmd(expand_T *xp, char_u *arg);
diff --git a/src/regexp_bt.c b/src/regexp_bt.c
index cf484e0bab..e3e7a18016 100644
--- a/src/regexp_bt.c
+++ b/src/regexp_bt.c
@@ -3444,7 +3444,7 @@ regmatch(
 		linenr_T    lnum = rex.reg_firstlnum + rex.lnum;
 		long_u	    vcol = 0;
 
-		if (lnum > 0 && lnum <= wp->w_buffer->b_ml.ml_line_count)
+		if (lnum >= 0 && lnum <= wp->w_buffer->b_ml.ml_line_count)
 		    vcol = (long_u)win_linetabsize(wp, lnum, rex.line,
 					      (colnr_T)(rex.input - rex.line));
 		if (!re_num_cmp(vcol + 1, scan))
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index f8717f5b1a..b398489272 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -6778,7 +6778,7 @@ nfa_regmatch(
 			linenr_T    lnum = rex.reg_firstlnum + rex.lnum;
 			long_u	    vcol = 0;
 
-			if (lnum > 0
+			if (lnum >= 0
 				   && lnum <= wp->w_buffer->b_ml.ml_line_count)
 			    vcol = (long_u)win_linetabsize(wp, lnum,
 								rex.line, col);
diff --git a/src/structs.h b/src/structs.h
index 6dc456da24..dba772d3b2 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -4618,7 +4618,6 @@ typedef struct {
 // Argument for lbr_chartabsize().
 typedef struct {
     win_T	*cts_win;
-    linenr_T	cts_lnum;	    // zero when not using text properties
     char_u	*cts_line;	    // start of the line
     char_u	*cts_ptr;	    // current position in line
 #ifdef FEAT_PROP_POPUP
diff --git a/src/testdir/test_assert.vim b/src/testdir/test_assert.vim
index 01e7718bb6..5d4abaa8a9 100644
--- a/src/testdir/test_assert.vim
+++ b/src/testdir/test_assert.vim
@@ -275,6 +275,21 @@ func Test_assert_fail_fails()
   endtry
   call assert_match("E1222: String or List required for argument 2", exp)
 
+  try
+    call assert_equal(0, assert_fails('xxx', [#{one: 1}]))
+  catch
+    let exp = v:exception
+  endtry
+  call assert_match("E731: Using a Dictionary as a String", exp)
+
+  let exp = ''
+  try
+    call assert_equal(0, assert_fails('xxx', ['E492', #{one: 1}]))
+  catch
+    let exp = v:exception
+  endtry
+  call assert_match("E731: Using a Dictionary as a String", exp)
+
   try
     call assert_equal(1, assert_fails('xxx', 'E492', '', 'burp'))
   catch
@@ -289,8 +304,8 @@ func Test_assert_fail_fails()
   endtry
   call assert_match("E1174: String required for argument 5", exp)
 
-  call assert_equal(1, assert_fails('c0', ['', '\1']))
-  call assert_match("Expected '\\\\\\\\1' but got 'E939: Positive count required: c0': c0", v:errors[0])
+  call assert_equal(1, assert_fails('c0', ['', '\(.\)\1']))
+  call assert_match("Expected '\\\\\\\\(.\\\\\\\\)\\\\\\\\1' but got 'E939: Positive count required: c0': c0", v:errors[0])
   call remove(v:errors, 0)
 endfunc
 
diff --git a/src/testdir/test_autochdir.vim b/src/testdir/test_autochdir.vim
index 332de8f2bf..eb402539ff 100644
--- a/src/testdir/test_autochdir.vim
+++ b/src/testdir/test_autochdir.vim
@@ -28,9 +28,9 @@ endfunc
 func Test_set_filename_other_window()
   let cwd = getcwd()
   call test_autochdir()
-  call mkdir('Xa')
-  call mkdir('Xb')
-  call mkdir('Xc')
+  call mkdir('Xa', 'R')
+  call mkdir('Xb', 'R')
+  call mkdir('Xc', 'R')
   try
     args Xa/aaa.txt Xb/bbb.txt
     set acd
@@ -45,9 +45,6 @@ func Test_set_filename_other_window()
     bwipe! aaa.txt
     bwipe! bbb.txt
     bwipe! ccc.txt
-    call delete('Xa', 'rf')
-    call delete('Xb', 'rf')
-    call delete('Xc', 'rf')
   endtry
 endfunc
 
@@ -56,7 +53,7 @@ func Test_acd_win_execute()
   set acd
   call test_autochdir()
 
-  call mkdir('XacdDir')
+  call mkdir('XacdDir', 'R')
   let winid = win_getid()
   new XacdDir/file
   call assert_match('testdir.XacdDir$', getcwd())
@@ -68,7 +65,6 @@ func Test_acd_win_execute()
   bwipe!
   set noacd
   call chdir(cwd)
-  call delete('XacdDir', 'rf')
 endfunc
 
 func Test_verbose_pwd()
@@ -78,7 +74,7 @@ func Test_verbose_pwd()
   edit global.txt
   call assert_match('\[global\].*testdir$', execute('verbose pwd'))
 
-  call mkdir('Xautodir')
+  call mkdir('Xautodir', 'R')
   split Xautodir/local.txt
   lcd Xautodir
   call assert_match('\[window\].*testdir[/\\]Xautodir', execute('verbose pwd'))
@@ -112,7 +108,6 @@ func Test_verbose_pwd()
 
   bwipe!
   call chdir(cwd)
-  call delete('Xautodir', 'rf')
 endfunc
 
 func Test_multibyte()
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index 532f7b537b..d1bd661206 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
@@ -707,14 +707,13 @@ func Test_BufEnter()
   call assert_equal('++', g:val)
 
   " Also get BufEnter when editing a directory
-  call mkdir('Xbufenterdir')
+  call mkdir('Xbufenterdir', 'D')
   split Xbufenterdir
   call assert_equal('+++', g:val)
 
   " On MS-Windows we can't edit the directory, make sure we wipe the right
   " buffer.
   bwipe! Xbufenterdir
-  call delete('Xbufenterdir', 'd')
   au! BufEnter
 
   " Editing a "nofile" buffer doesn't read the file but does trigger BufEnter
@@ -1902,11 +1901,10 @@ func Test_BufWriteCmd()
   new
   file Xbufwritecmd
   set buftype=acwrite
-  call mkdir('Xbufwritecmd')
+  call mkdir('Xbufwritecmd', 'D')
   write
   " BufWriteCmd should be triggered even if a directory has the same name
   call assert_equal(1, g:written)
-  call delete('Xbufwritecmd', 'd')
   unlet g:written
   au! BufWriteCmd
   bwipe!
@@ -2710,7 +2708,7 @@ func Test_throw_in_BufWritePre()
 endfunc
 
 func Test_autocmd_in_try_block()
-  call mkdir('Xintrydir')
+  call mkdir('Xintrydir', 'R')
   au BufEnter * let g:fname = expand('%')
   try
     edit Xintrydir/
@@ -2719,7 +2717,6 @@ func Test_autocmd_in_try_block()
 
   unlet g:fname
   au! BufEnter
-  call delete('Xintrydir', 'rf')
 endfunc
 
 func Test_autocmd_SafeState()
diff --git a/src/testdir/test_eval_stuff.vim b/src/testdir/test_eval_stuff.vim
index 3669cfd40b..0081d89a52 100644
--- a/src/testdir/test_eval_stuff.vim
+++ b/src/testdir/test_eval_stuff.vim
@@ -44,6 +44,64 @@ func Test_mkdir_p()
   call assert_fails('call mkdir("abc", [], [])', 'E745:')
 endfunc
 
+func DoMkdirDel(name)
+  call mkdir(a:name, 'pD')
+  call assert_true(isdirectory(a:name))
+endfunc
+
+func DoMkdirDelAddFile(name)
+  call mkdir(a:name, 'pD')
+  call assert_true(isdirectory(a:name))
+  call writefile(['text'], a:name .. '/file')
+endfunc
+
+func DoMkdirDelRec(name)
+  call mkdir(a:name, 'pR')
+  call assert_true(isdirectory(a:name))
+endfunc
+
+func DoMkdirDelRecAddFile(name)
+  call mkdir(a:name, 'pR')
+  call assert_true(isdirectory(a:name))
+  call writefile(['text'], a:name .. '/file')
+endfunc
+
+func Test_mkdir_defer_del()
+  " Xtopdir/tmp is created thus deleted, not Xtopdir itself
+  call mkdir('Xtopdir', 'R')
+  call DoMkdirDel('Xtopdir/tmp')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_false(isdirectory('Xtopdir/tmp'))
+
+  " Deletion fails because "tmp" contains "sub"
+  call DoMkdirDel('Xtopdir/tmp/sub')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_true(isdirectory('Xtopdir/tmp'))
+  call delete('Xtopdir/tmp', 'rf')
+
+  " Deletion fails because "tmp" contains "file"
+  call DoMkdirDelAddFile('Xtopdir/tmp')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_true(isdirectory('Xtopdir/tmp'))
+  call assert_true(filereadable('Xtopdir/tmp/file'))
+  call delete('Xtopdir/tmp', 'rf')
+
+  " Xtopdir/tmp is created thus deleted, not Xtopdir itself
+  call DoMkdirDelRec('Xtopdir/tmp')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_false(isdirectory('Xtopdir/tmp'))
+
+  " Deletion works even though "tmp" contains "sub"
+  call DoMkdirDelRec('Xtopdir/tmp/sub')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_false(isdirectory('Xtopdir/tmp'))
+
+  " Deletion works even though "tmp" contains "file"
+  call DoMkdirDelRecAddFile('Xtopdir/tmp')
+  call assert_true(isdirectory('Xtopdir'))
+  call assert_false(isdirectory('Xtopdir/tmp'))
+endfunc
+
 func Test_line_continuation()
   let array = [5,
 	"\ ignore this
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 551602fbe1..9d2677c7fc 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -275,7 +275,7 @@ let s:filename_checks = {
     \ 'jam': ['file.jpl', 'file.jpr', 'JAM-file.file', 'JAM.file', 'Prl-file.file', 'Prl.file'],
     \ 'java': ['file.java', 'file.jav'],
     \ 'javacc': ['file.jj', 'file.jjt'],
-    \ 'javascript': ['file.js', 'file.javascript', 'file.es', 'file.mjs', 'file.cjs'],
+    \ 'javascript': ['file.js', 'file.jsm', 'file.javascript', 'file.es', 'file.mjs', 'file.cjs'],
     \ 'javascript.glimmer': ['file.gjs'],
     \ 'javascriptreact': ['file.jsx'],
     \ 'jess': ['file.clp'],
diff --git a/src/testdir/test_gui.vim b/src/testdir/test_gui.vim
index c2b0815e89..d196c8edf2 100644
--- a/src/testdir/test_gui.vim
+++ b/src/testdir/test_gui.vim
@@ -1614,12 +1614,15 @@ func Test_gui_CTRL_SHIFT_V()
 endfunc
 
 func Test_gui_dialog_file()
+  " make sure the file does not exist, otherwise a dialog makes Vim hang
+  call delete('Xdialfile')
+
   let lines =<< trim END
     file Xdialfile
     normal axxx
     confirm qa
   END
-  call writefile(lines, 'Xlines')
+  call writefile(lines, 'Xlines', 'D')
   let prefix = '!'
   if has('win32')
     let prefix = '!start '
@@ -1636,7 +1639,6 @@ func Test_gui_dialog_file()
 
   call delete('Xdialog')
   call delete('Xdialfile')
-  call delete('Xlines')
 endfunc
 
 " Test for sending low level key presses
diff --git a/src/testdir/test_listdict.vim b/src/testdir/test_listdict.vim
index bf3117bbbd..63ba47fabe 100644
--- a/src/testdir/test_listdict.vim
+++ b/src/testdir/test_listdict.vim
@@ -321,6 +321,10 @@ func Test_dict()
 
   " allow key starting with number at the start, not a curly expression
   call assert_equal({'1foo': 77}, #{1foo: 77})
+
+  " #{expr} is not a curly expression
+  let x = 'x'
+  call assert_equal(#{g: x}, #{g:x})
 endfunc
 
 " This was allowed in legacy Vim script
diff --git a/src/testdir/test_regexp_latin.vim b/src/testdir/test_regexp_latin.vim
index bc08439d15..6f3ffe23ff 100644
--- a/src/testdir/test_regexp_latin.vim
+++ b/src/testdir/test_regexp_latin.vim
@@ -30,11 +30,13 @@ endfunc
 func Test_equivalence_re1()
   set re=1
   call s:equivalence_test()
+  set re=0
 endfunc
 
 func Test_equivalence_re2()
   set re=2
   call s:equivalence_test()
+  set re=0
 endfunc
 
 func Test_recursive_substitute()
@@ -67,6 +69,7 @@ func Test_eow_with_optional()
     let actual = matchlist('abc def', '\(abc\>\)\?\s*\(def\)')
     call assert_equal(expected, actual)
   endfor
+  set re=0
 endfunc
 
 func Test_backref()
@@ -1141,4 +1144,14 @@ def Test_compare_columns()
   prop_type_delete('name')
 enddef
 
+def Test_compare_column_matchstr()
+  enew
+  set re=1
+  call assert_equal('aaa', matchstr('aaaaaaaaaaaaaaaaaaaa', '.*\%<5v'))
+  set re=2
+  call assert_equal('aaa', matchstr('aaaaaaaaaaaaaaaaaaaa', '.*\%<5v'))
+  set re=0
+enddef
+
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_user_func.vim b/src/testdir/test_user_func.vim
index ecf90b61ab..6b17534406 100644
--- a/src/testdir/test_user_func.vim
+++ b/src/testdir/test_user_func.vim
@@ -625,6 +625,29 @@ func Test_defer_quitall()
   call assert_false(filereadable('XQuitallTwo'))
 endfunc
 
+func Test_defer_quitall_in_expr_func()
+  let lines =<< trim END
+      def DefIndex(idx: number, val: string): bool
+        call writefile([idx .. ': ' .. val], 'Xentry' .. idx, 'D')
+        if val == 'b'
+          qa!
+        endif
+        return val == 'c'
+      enddef
+
+      def Test_defer_in_funcref()
+        assert_equal(2, indexof(['a', 'b', 'c'], funcref('g:DefIndex')))
+      enddef
+      call Test_defer_in_funcref()
+  END
+  call writefile(lines, 'XdeferQuitallExpr', 'D')
+  let res = system(GetVimCommandClean() .. ' -X -S XdeferQuitallExpr')
+  call assert_equal(0, v:shell_error)
+  call assert_false(filereadable('Xentry0'))
+  call assert_false(filereadable('Xentry1'))
+  call assert_false(filereadable('Xentry2'))
+endfunc
+
 func FuncIndex(idx, val)
   call writefile([a:idx .. ': ' .. a:val], 'Xentry' .. a:idx, 'D')
   return a:val == 'c'
@@ -635,6 +658,11 @@ def DefIndex(idx: number, val: string): bool
   return val == 'c'
 enddef
 
+def DefIndexXtra(xtra: string, idx: number, val: string): bool
+  call writefile([idx .. ': ' .. val], 'Xentry' .. idx, 'D')
+  return val == 'c'
+enddef
+
 def Test_defer_in_funcref()
   assert_equal(2, indexof(['a', 'b', 'c'], function('g:FuncIndex')))
   assert_false(filereadable('Xentry0'))
@@ -655,6 +683,16 @@ def Test_defer_in_funcref()
   assert_false(filereadable('Xentry0'))
   assert_false(filereadable('Xentry1'))
   assert_false(filereadable('Xentry2'))
+
+  assert_equal(2, indexof(['a', 'b', 'c'], function(g:DefIndexXtra, ['xtra'])))
+  assert_false(filereadable('Xentry0'))
+  assert_false(filereadable('Xentry1'))
+  assert_false(filereadable('Xentry2'))
+
+  assert_equal(2, indexof(['a', 'b', 'c'], funcref(g:DefIndexXtra, ['xtra'])))
+  assert_false(filereadable('Xentry0'))
+  assert_false(filereadable('Xentry1'))
+  assert_false(filereadable('Xentry2'))
 enddef
 
 
diff --git a/src/testdir/test_window_cmd.vim b/src/testdir/test_window_cmd.vim
index 44fd646392..e38c8a8107 100644
--- a/src/testdir/test_window_cmd.vim
+++ b/src/testdir/test_window_cmd.vim
@@ -1617,4 +1617,19 @@ func Test_window_alloc_failure()
   tabonly
 endfunc
 
+func Test_win_equal_last_status()
+  let save_lines = &lines
+  set lines=20
+  set splitbelow
+  set laststatus=0
+
+  split | split | quit
+  call assert_equal(winheight(1), winheight(2))
+
+  let &lines = save_lines
+  set splitbelow&
+  set laststatus&
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_writefile.vim b/src/testdir/test_writefile.vim
index dddc5c9539..f2b8aba57f 100644
--- a/src/testdir/test_writefile.vim
+++ b/src/testdir/test_writefile.vim
@@ -950,6 +950,19 @@ func Test_write_with_deferred_delete()
   call assert_equal('', glob('XdefdeferDelete'))
 endfunc
 
+func DoWriteFile()
+  call writefile(['text'], 'Xthefile', 'D')
+  cd ..
+endfunc
+
+func Test_write_defer_delete_chdir()
+  let dir = getcwd()
+  call DoWriteFile()
+  call assert_notequal(dir, getcwd())
+  call chdir(dir)
+  call assert_equal('', glob('Xthefile'))
+endfunc
+
 " Check that buffer is written before triggering QuitPre
 func Test_wq_quitpre_autocommand()
   edit Xsomefile
diff --git a/src/testing.c b/src/testing.c
index 8c682cf6bc..fb5c9ab4cc 100644
--- a/src/testing.c
+++ b/src/testing.c
@@ -616,6 +616,11 @@ f_assert_fails(typval_T *argvars, typval_T *rettv)
     in_assert_fails = TRUE;
 
     do_cmdline_cmd(cmd);
+
+    // reset here for any errors reported below
+    trylevel = save_trylevel;
+    suppress_errthrow = FALSE;
+
     if (called_emsg == called_emsg_before)
     {
 	prepare_assert_error(&ga);
@@ -654,6 +659,8 @@ f_assert_fails(typval_T *argvars, typval_T *rettv)
 	    CHECK_LIST_MATERIALIZE(list);
 	    tv = &list->lv_first->li_tv;
 	    expected = tv_get_string_buf_chk(tv, buf);
+	    if (expected == NULL)
+		goto theend;
 	    if (!pattern_match(expected, actual, FALSE))
 	    {
 		error_found = TRUE;
@@ -667,6 +674,8 @@ f_assert_fails(typval_T *argvars, typval_T *rettv)
 		{
 		    tv = &list->lv_u.mat.lv_last->li_tv;
 		    expected = tv_get_string_buf_chk(tv, buf);
+		    if (expected == NULL)
+			goto theend;
 		    if (!pattern_match(expected, actual, FALSE))
 		    {
 			error_found = TRUE;
diff --git a/src/userfunc.c b/src/userfunc.c
index 76ab6b9d86..7b6034aaff 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -2580,6 +2580,40 @@ funcdepth_restore(int depth)
     funcdepth = depth;
 }
 
+/*
+ * Allocate a funccall_T, link it in current_funccal and fill in "fp" and
+ * "rettv".
+ * Must be followed by one call to remove_funccal() or cleanup_function_call().
+ * Returns NULL when allocation fails.
+ */
+    funccall_T *
+create_funccal(ufunc_T *fp, typval_T *rettv)
+{
+    funccall_T *fc = ALLOC_CLEAR_ONE(funccall_T);
+
+    if (fc == NULL)
+	return NULL;
+    fc->fc_caller = current_funccal;
+    current_funccal = fc;
+    fc->fc_func = fp;
+    func_ptr_ref(fp);
+    fc->fc_rettv = rettv;
+    return fc;
+}
+
+/*
+ * To be called when returning from a compiled function; restores
+ * current_funccal.
+ */
+    void
+remove_funccal()
+{
+    funccall_T *fc = current_funccal;
+
+    current_funccal = fc->fc_caller;
+    free_funccal(fc);
+}
+
 /*
  * Call a user function.
  */
@@ -2627,20 +2661,15 @@ call_user_func(
 
     line_breakcheck();		// check for CTRL-C hit
 
-    fc = ALLOC_CLEAR_ONE(funccall_T);
+    fc = create_funccal(fp, rettv);
     if (fc == NULL)
 	return;
-    fc->fc_caller = current_funccal;
-    current_funccal = fc;
-    fc->fc_func = fp;
-    fc->fc_rettv = rettv;
     fc->fc_level = ex_nesting_level;
     // Check if this function has a breakpoint.
     fc->fc_breakpoint = dbg_find_breakpoint(FALSE, fp->uf_name, (linenr_T)0);
     fc->fc_dbg_tick = debug_tick;
     // Set up fields for closure.
     ga_init2(&fc->fc_ufuncs, sizeof(ufunc_T *), 1);
-    func_ptr_ref(fp);
 
     if (fp->uf_def_status != UF_NOT_COMPILED)
     {
@@ -2653,7 +2682,7 @@ call_user_func(
 	    profile_may_start_func(&profile_info, fp, caller);
 #endif
 	sticky_cmdmod_flags = 0;
-	call_def_function(fp, argcount, argvars, funcexe->fe_partial,
+	call_def_function(fp, argcount, argvars, 0, funcexe->fe_partial,
 								    fc, rettv);
 	funcdepth_decrement();
 #ifdef FEAT_PROFILE
@@ -2661,8 +2690,7 @@ call_user_func(
 				  || (caller != NULL && caller->uf_profiling)))
 	    profile_may_end_func(&profile_info, fp, caller);
 #endif
-	current_funccal = fc->fc_caller;
-	free_funccal(fc);
+	remove_funccal();
 	sticky_cmdmod_flags = save_sticky_cmdmod_flags;
 	return;
     }
@@ -5621,6 +5649,21 @@ ex_defer_inner(
     return add_defer(name, argcount, argvars);
 }
 
+/*
+ * Return TRUE if currently inside a function call.
+ * Give an error message and return FALSE when not.
+ */
+    int
+can_add_defer(void)
+{
+    if (!in_def_function() && get_current_funccal() == NULL)
+    {
+	semsg(_(e_str_not_inside_function), "defer");
+	return FALSE;
+    }
+    return TRUE;
+}
+
 /*
  * Add a deferred call for "name" with arguments "argvars[argcount]".
  * Consumes "argvars[]".
diff --git a/src/version.c b/src/version.c
index 8a58359823..8c58c4911d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -718,6 +718,32 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    412,
+/**/
+    411,
+/**/
+    410,
+/**/
+    409,
+/**/
+    408,
+/**/
+    407,
+/**/
+    406,
+/**/
+    405,
+/**/
+    404,
+/**/
+    403,
+/**/
+    402,
+/**/
+    401,
+/**/
+    400,
 /**/
     399,
 /**/
diff --git a/src/vim9.h b/src/vim9.h
index 22a3f3990e..9d72b96464 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -759,3 +759,5 @@ typedef enum {
 #define TVTT_DO_MEMBER	    1
 #define TVTT_MORE_SPECIFIC  2	// get most specific type for member
 
+// flags for call_def_function()
+#define DEF_USE_PT_ARGV	    1	// use the partial arguments
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 46251545ed..30ff7a7755 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -5272,16 +5272,21 @@ call_def_function(
     ufunc_T	*ufunc,
     int		argc_arg,	// nr of arguments
     typval_T	*argv,		// arguments
+    int		flags,		// DEF_ flags
     partial_T	*partial,	// optional partial for context
     funccall_T	*funccal,
     typval_T	*rettv)		// return value
 {
     ectx_T	ectx;		// execution context
     int		argc = argc_arg;
+    int		partial_argc = partial == NULL
+				  || (flags & DEF_USE_PT_ARGV) == 0
+							? 0 : partial->pt_argc;
+    int		total_argc = argc + partial_argc;
     typval_T	*tv;
     int		idx;
     int		ret = FAIL;
-    int		defcount = ufunc->uf_args.ga_len - argc;
+    int		defcount = ufunc->uf_args.ga_len - total_argc;
     sctx_T	save_current_sctx = current_sctx;
     int		did_emsg_before = did_emsg_cumul + did_emsg;
     int		save_suppress_errthrow = suppress_errthrow;
@@ -5345,14 +5350,14 @@ call_def_function(
     ectx.ec_did_emsg_before = did_emsg_before;
     ++ex_nesting_level;
 
-    idx = argc - ufunc->uf_args.ga_len;
+    idx = total_argc - ufunc->uf_args.ga_len;
     if (idx > 0 && ufunc->uf_va_name == NULL)
     {
 	semsg(NGETTEXT(e_one_argument_too_many, e_nr_arguments_too_many,
-			idx), idx);
+								    idx), idx);
 	goto failed_early;
     }
-    idx = argc - ufunc->uf_args.ga_len + ufunc->uf_def_args.ga_len;
+    idx = total_argc - ufunc->uf_args.ga_len + ufunc->uf_def_args.ga_len;
     if (idx < 0)
     {
 	semsg(NGETTEXT(e_one_argument_too_few, e_nr_arguments_too_few,
@@ -5360,15 +5365,19 @@ call_def_function(
 	goto failed_early;
     }
 
-    // Put arguments on the stack, but no more than what the function expects.
-    // A lambda can be called with more arguments than it uses.
-    for (idx = 0; idx < argc
+    // Put values from the partial and arguments on the stack, but no more than
+    // what the function expects.  A lambda can be called with more arguments
+    // than it uses.
+    for (idx = 0; idx < total_argc
 	    && (ufunc->uf_va_name != NULL || idx < ufunc->uf_args.ga_len);
 									 ++idx)
     {
+	int argv_idx = idx - partial_argc;
+
+	tv = idx < partial_argc ? partial->pt_argv + idx : argv + argv_idx;
 	if (idx >= ufunc->uf_args.ga_len - ufunc->uf_def_args.ga_len
-		&& argv[idx].v_type == VAR_SPECIAL
-		&& argv[idx].vval.v_number == VVAL_NONE)
+		&& tv->v_type == VAR_SPECIAL
+		&& tv->vval.v_number == VVAL_NONE)
 	{
 	    // Use the default value.
 	    STACK_TV_BOT(0)->v_type = VAR_UNKNOWN;
@@ -5377,10 +5386,10 @@ call_def_function(
 	{
 	    if (ufunc->uf_arg_types != NULL && idx < ufunc->uf_args.ga_len
 		    && check_typval_arg_type(
-			ufunc->uf_arg_types[idx], &argv[idx],
-							NULL, idx + 1) == FAIL)
+			ufunc->uf_arg_types[idx], tv,
+						   NULL, argv_idx + 1) == FAIL)
 		goto failed_early;
-	    copy_tv(&argv[idx], STACK_TV_BOT(0));
+	    copy_tv(tv, STACK_TV_BOT(0));
 	}
 	++ectx.ec_stack.ga_len;
     }
diff --git a/src/window.c b/src/window.c
index cb45f6d509..8daab2f5f0 100644
--- a/src/window.c
+++ b/src/window.c
@@ -2718,6 +2718,14 @@ win_close(win_T *win, int free_buf)
 	// using the window.
 	check_cursor();
     }
+
+    /*
+     * If last window has a status line now and we don't want one, remove the
+     * status line.  Do this before win_equal(), because it may change the
+     * height of a window
+     */
+    last_status(FALSE);
+
     if (p_ea && (*p_ead == 'b' || *p_ead == dir))
 	// If the frame of the closed window contains the new current window,
 	// only resize that frame.  Otherwise resize all windows.
@@ -2747,12 +2755,6 @@ win_close(win_T *win, int free_buf)
 	--dont_parse_messages;
 #endif
 
-    /*
-     * If last window has a status line now and we don't want one,
-     * remove the status line.
-     */
-    last_status(FALSE);
-
     // After closing the help window, try restoring the window layout from
     // before it was opened.
     if (help_window)