patch 8.2.4642: Vim9: in :def function script var cannot be null

Problem:    Vim9: in :def function script var cannot be null.
Solution:   Only initialize a script variable when not set to a null value.
            (closes #10034)

src/drawscreen.c

@@ -3032,23 +3032,6 @@ redraw_asap(int type)
 }
 #endif
 
-#if defined(FEAT_SYN_HL) || defined(PROTO)
-/*
- * Check if the cursor moved and 'cursorline' is set.  Mark for a VALID redraw
- * if needed.
- */
-    void
-check_redraw_cursorline(void)
-{
-    // When 'cursorlineopt' is "screenline" need to redraw always.
-    if (curwin->w_p_cul
-	    && (curwin->w_last_cursorline != curwin->w_cursor.lnum
-		|| (curwin->w_p_culopt_flags & CULOPT_SCRLINE))
-	    && !char_avail())
-	redraw_later(VALID);
-}
-#endif
-
 /*
  * Invoked after an asynchronous callback is called.
  * If an echo command was used the cursor needs to be put back where
@@ -3093,10 +3076,9 @@ redraw_after_callback(int call_update_screen, int do_message)
     }
     else if (State & (NORMAL | INSERT | TERMINAL))
     {
-#ifdef FEAT_SYN_HL
-	// might need to update for 'cursorline'
-	check_redraw_cursorline();
-#endif
+	update_topline();
+	validate_cursor();
+
 	// keep the command line if possible
 	update_screen(VALID_NO_UPDATE);
 	setcursor();

src/edit.c

@@ -1058,10 +1058,6 @@ doESCkey:
 	case K_COMMAND:		    // <Cmd>command<CR>
 	case K_SCRIPT_COMMAND:	    // <ScriptCmd>command<CR>
 	    do_cmdkey_command(c, 0);
-#ifdef FEAT_SYN_HL
-	    // Might need to update for 'cursorline'.
-	    check_redraw_cursorline();
-#endif
 #ifdef FEAT_TERMINAL
 	    if (term_use_loop())
 		// Started a terminal that gets the input, exit Insert mode.

src/evalvars.c

@@ -2823,7 +2823,7 @@ eval_variable(
 	    {
 		if (tv->v_type == VAR_DICT && tv->vval.v_dict == NULL
 			  && ((type != NULL && type != &t_dict_empty)
-							   || !in_vim9script()))
+							  || !in_vim9script()))
 		{
 		    tv->vval.v_dict = dict_alloc();
 		    if (tv->vval.v_dict != NULL)
@@ -2843,6 +2843,14 @@ eval_variable(
 			tv->vval.v_list->lv_type = alloc_type(type);
 		    }
 		}
+		else if (tv->v_type == VAR_BLOB && tv->vval.v_blob == NULL
+				    && ((type != NULL && type != &t_blob_null)
+							  || !in_vim9script()))
+		{
+		    tv->vval.v_blob = blob_alloc();
+		    if (tv->vval.v_blob != NULL)
+			++tv->vval.v_blob->bv_refcount;
+		}
 	    }
 	    copy_tv(tv, rettv);
 	}

src/ex_docmd.c

@@ -2782,7 +2782,7 @@ parse_command_modifiers(
 	cmdmod_T    *cmod,
 	int	    skip_only)
 {
-    char_u  *cmd_start;
+    char_u  *cmd_start = NULL;
     char_u  *p;
     int	    starts_with_colon = FALSE;
     int	    vim9script = in_vim9script();
@@ -3092,15 +3092,21 @@ parse_command_modifiers(
 	break;
     }
 
-    if (has_visual_range && eap->cmd > cmd_start)
+    if (has_visual_range)
     {
-	// Move the '<,'> range to after the modifiers and insert a colon.
-	// Since the modifiers have been parsed put the colon on top of the
-	// space: "'<,'>mod cmd" -> "mod:'<,'>cmd
-	// Put eap->cmd after the colon.
-	mch_memmove(cmd_start - 5, cmd_start, eap->cmd - cmd_start);
-	eap->cmd -= 5;
-	mch_memmove(eap->cmd - 1, ":'<,'>", 6);
+	if (eap->cmd > cmd_start)
+	{
+	    // Move the '<,'> range to after the modifiers and insert a colon.
+	    // Since the modifiers have been parsed put the colon on top of the
+	    // space: "'<,'>mod cmd" -> "mod:'<,'>cmd
+	    // Put eap->cmd after the colon.
+	    mch_memmove(cmd_start - 5, cmd_start, eap->cmd - cmd_start);
+	    eap->cmd -= 5;
+	    mch_memmove(eap->cmd - 1, ":'<,'>", 6);
+	}
+	else
+	    // no modifiers, move the pointer back
+	    eap->cmd -= 5;
     }
 
     return OK;

src/globals.h

@@ -405,6 +405,7 @@ EXTERN type_T t_number_bool INIT6(VAR_NUMBER, 0, 0, TTFLAG_STATIC|TTFLAG_BOOL_OK
 EXTERN type_T t_float INIT6(VAR_FLOAT, 0, 0, TTFLAG_STATIC, NULL, NULL);
 EXTERN type_T t_string INIT6(VAR_STRING, 0, 0, TTFLAG_STATIC, NULL, NULL);
 EXTERN type_T t_blob INIT6(VAR_BLOB, 0, 0, TTFLAG_STATIC, NULL, NULL);
+EXTERN type_T t_blob_null INIT6(VAR_BLOB, 0, 0, TTFLAG_STATIC, &t_void, NULL);
 EXTERN type_T t_job INIT6(VAR_JOB, 0, 0, TTFLAG_STATIC, NULL, NULL);
 EXTERN type_T t_channel INIT6(VAR_CHANNEL, 0, 0, TTFLAG_STATIC, NULL, NULL);
 
@@ -702,10 +703,10 @@ EXTERN win_T	*lastwin;		// last window
 EXTERN win_T	*prevwin INIT(= NULL);	// previous window
 #define ONE_WINDOW (firstwin == lastwin)
 #define W_NEXT(wp) ((wp)->w_next)
-#define FOR_ALL_WINDOWS(wp) for (wp = firstwin; wp != NULL; wp = wp->w_next)
+#define FOR_ALL_WINDOWS(wp) for ((wp) = firstwin; (wp) != NULL; (wp) = (wp)->w_next)
 #define FOR_ALL_FRAMES(frp, first_frame) \
-    for (frp = first_frame; frp != NULL; frp = frp->fr_next)
-#define FOR_ALL_TABPAGES(tp) for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
+    for ((frp) = first_frame; (frp) != NULL; (frp) = (frp)->fr_next)
+#define FOR_ALL_TABPAGES(tp) for ((tp) = first_tabpage; (tp) != NULL; (tp) = (tp)->tp_next)
 #define FOR_ALL_WINDOWS_IN_TAB(tp, wp) \
     for ((wp) = ((tp) == NULL || (tp) == curtab) \
 	    ? firstwin : (tp)->tp_firstwin; (wp); (wp) = (wp)->w_next)
@@ -778,7 +779,7 @@ EXTERN buf_T	*curbuf INIT(= NULL);	// currently active buffer
 
 // Iterate through all the signs placed in a buffer
 #define FOR_ALL_SIGNS_IN_BUF(buf, sign) \
-	for (sign = buf->b_signlist; sign != NULL; sign = sign->se_next)
+	for ((sign) = (buf)->b_signlist; (sign) != NULL; (sign) = (sign)->se_next)
 
 // Flag that is set when switching off 'swapfile'.  It means that all blocks
 // are to be loaded into memory.  Shouldn't be global...
@@ -1000,7 +1001,7 @@ EXTERN JMP_BUF x_jump_env;
 #define DBCS_CHT	950	// taiwan
 #define DBCS_CHTU	9950	// euc-tw
 #define DBCS_2BYTE	1	// 2byte-
-#define DBCS_DEBUG	-1
+#define DBCS_DEBUG	(-1)
 
 EXTERN int	enc_dbcs INIT(= 0);		// One of DBCS_xxx values if
 						// DBCS encoding

src/gui.h

@@ -100,7 +100,7 @@
 #endif
 
 // Indices for arrays of scrollbars
-#define SBAR_NONE	    -1
+#define SBAR_NONE	    (-1)
 #define SBAR_LEFT	    0
 #define SBAR_RIGHT	    1
 #define SBAR_BOTTOM	    2
@@ -198,10 +198,10 @@ typedef struct GuiScrollbar
 typedef long	    guicolor_T;	// handle for a GUI color; for X11 this should
 				// be "Pixel", but that's an unsigned and we
 				// need a signed value
-#define INVALCOLOR (guicolor_T)-11111	// number for invalid color; on 32 bit
+#define INVALCOLOR ((guicolor_T)-11111)	// number for invalid color; on 32 bit
 				   // displays there is a tiny chance this is an
 				   // actual color
-#define CTERMCOLOR (guicolor_T)-11110	// only used for cterm.bg_rgb and
+#define CTERMCOLOR ((guicolor_T)-11110)	// only used for cterm.bg_rgb and
 					// cterm.fg_rgb: use cterm color
 
 #ifdef FEAT_GUI_GTK

src/if_py_both.h

@@ -30,9 +30,9 @@ static const char *vim_special_path = "_vim_path_";
 #define PyErr_FORMAT2(exc, str, arg1, arg2) PyErr_Format(exc, _(str), arg1,arg2)
 #define PyErr_VIM_FORMAT(str, arg) PyErr_FORMAT(VimError, str, arg)
 
-#define Py_TYPE_NAME(obj) (obj->ob_type->tp_name == NULL \
+#define Py_TYPE_NAME(obj) ((obj)->ob_type->tp_name == NULL \
 	? "(NULL)" \
-	: obj->ob_type->tp_name)
+	: (obj)->ob_type->tp_name)
 
 #define RAISE_NO_EMPTY_KEYS PyErr_SET_STRING(PyExc_ValueError, \
 					    N_("empty keys are not allowed"))
@@ -6686,7 +6686,7 @@ init_structs(void)
 }
 
 #define PYTYPE_READY(type) \
-    if (PyType_Ready(&type)) \
+    if (PyType_Ready(&(type))) \
 	return -1;
 
     static int

src/macros.h

@@ -232,11 +232,11 @@
 // Advance multi-byte pointer, do not skip over composing chars.
 #define MB_CPTR_ADV(p)	    p += enc_utf8 ? utf_ptr2len(p) : (*mb_ptr2len)(p)
 // Backup multi-byte pointer. Only use with "p" > "s" !
-#define MB_PTR_BACK(s, p)  p -= has_mbyte ? ((*mb_head_off)(s, p - 1) + 1) : 1
+#define MB_PTR_BACK(s, p)  p -= has_mbyte ? ((*mb_head_off)(s, (p) - 1) + 1) : 1
 // get length of multi-byte char, not including composing chars
 #define MB_CPTR2LEN(p)	    (enc_utf8 ? utf_ptr2len(p) : (*mb_ptr2len)(p))
 
-#define MB_COPY_CHAR(f, t) do { if (has_mbyte) mb_copy_char(&f, &t); else *t++ = *f++; } while (0)
+#define MB_COPY_CHAR(f, t) do { if (has_mbyte) mb_copy_char(&(f), &(t)); else *(t)++ = *(f)++; } while (0)
 #define MB_CHARLEN(p)	    (has_mbyte ? mb_charlen(p) : (int)STRLEN(p))
 #define MB_CHAR2LEN(c)	    (has_mbyte ? mb_char2len(c) : 1)
 #define PTR2CHAR(p)	    (has_mbyte ? mb_ptr2char(p) : (int)*(p))
@@ -313,7 +313,7 @@
  * HI2DI() converts a hashitem pointer to a dictitem pointer.
  */
 #define DI2HIKEY(di) ((di)->di_key)
-#define HIKEY2DI(p)  ((dictitem_T *)(p - offsetof(dictitem_T, di_key)))
+#define HIKEY2DI(p)  ((dictitem_T *)((p) - offsetof(dictitem_T, di_key)))
 #define HI2DI(hi)     HIKEY2DI((hi)->hi_key)
 
 /*
@@ -376,9 +376,9 @@
 #define CHECK_LIST_MATERIALIZE(l) if ((l)->lv_first == &range_list_item) range_list_materialize(l)
 
 // Inlined version of ga_grow() with optimized condition that it fails.
-#define GA_GROW_FAILS(gap, n) unlikely((((gap)->ga_maxlen - (gap)->ga_len < n) ? ga_grow_inner((gap), (n)) : OK) == FAIL)
+#define GA_GROW_FAILS(gap, n) unlikely((((gap)->ga_maxlen - (gap)->ga_len < (n)) ? ga_grow_inner((gap), (n)) : OK) == FAIL)
 // Inlined version of ga_grow() with optimized condition that it succeeds.
-#define GA_GROW_OK(gap, n) likely((((gap)->ga_maxlen - (gap)->ga_len < n) ? ga_grow_inner((gap), (n)) : OK) == OK)
+#define GA_GROW_OK(gap, n) likely((((gap)->ga_maxlen - (gap)->ga_len < (n)) ? ga_grow_inner((gap), (n)) : OK) == OK)
 
 #ifndef MIN
 # define MIN(a, b) ((a) < (b) ? (a) : (b))

src/main.c

@@ -1384,10 +1384,6 @@ main_loop(
 	    update_topline();
 	    validate_cursor();
 
-#ifdef FEAT_SYN_HL
-	    // Might need to update for 'cursorline'.
-	    check_redraw_cursorline();
-#endif
 	    if (VIsual_active)
 		update_curbuf(INVERTED); // update inverted part
 	    else if (must_redraw)

src/move.c

@@ -135,6 +135,26 @@ redraw_for_cursorline(win_T *wp)
     }
 }
 
+#ifdef FEAT_SYN_HL
+/*
+ * Redraw when w_virtcol changes and 'cursorcolumn' is set or 'cursorlineopt'
+ * contains "screenline".
+ */
+    static void
+redraw_for_cursorcolumn(win_T *wp)
+{
+    if ((wp->w_valid & VALID_VIRTCOL) == 0 && !pum_visible())
+    {
+	// When 'cursorcolumn' is set need to redraw with SOME_VALID.
+	if (wp->w_p_cuc)
+	    redraw_win_later(wp, SOME_VALID);
+	// When 'cursorlineopt' contains "screenline" need to redraw with VALID.
+	else if (wp->w_p_cul && (wp->w_p_culopt_flags & CULOPT_SCRLINE))
+	    redraw_win_later(wp, VALID);
+    }
+}
+#endif
+
 /*
  * Update curwin->w_topline and redraw if necessary.
  * Used to update the screen before printing a message.
@@ -798,11 +818,10 @@ validate_virtcol_win(win_T *wp)
     if (!(wp->w_valid & VALID_VIRTCOL))
     {
 	getvvcol(wp, &wp->w_cursor, NULL, &(wp->w_virtcol), NULL);
-	wp->w_valid |= VALID_VIRTCOL;
 #ifdef FEAT_SYN_HL
-	if (wp->w_p_cuc && !pum_visible())
-	    redraw_win_later(wp, SOME_VALID);
+	redraw_for_cursorcolumn(wp);
 #endif
+	wp->w_valid |= VALID_VIRTCOL;
     }
 }
 
@@ -1169,10 +1188,7 @@ curs_columns(
 	redraw_later(NOT_VALID);
 
 #ifdef FEAT_SYN_HL
-    // Redraw when w_virtcol changes and 'cursorcolumn' is set
-    if (curwin->w_p_cuc && (curwin->w_valid & VALID_VIRTCOL) == 0
-	    && !pum_visible())
-	redraw_later(SOME_VALID);
+    redraw_for_cursorcolumn(curwin);
 #endif
 #if defined(FEAT_PROP_POPUP) && defined(FEAT_TERMINAL)
     if (popup_is_popup(curwin) && curbuf->b_term != NULL)

src/normal.c

@@ -6971,10 +6971,6 @@ nv_edit(cmdarg_T *cap)
 	    coladvance(getviscol());
 	    State = save_State;
 	}
-#ifdef FEAT_SYN_HL
-	// Might need to update for 'cursorline'.
-	check_redraw_cursorline();
-#endif
 
 	invoke_edit(cap, FALSE, cap->cmdchar, FALSE);
     }

src/option.h

@@ -131,7 +131,7 @@ typedef enum {
 #endif
 
 // end-of-line style
-#define EOL_UNKNOWN	-1	// not defined yet
+#define EOL_UNKNOWN	(-1)	// not defined yet
 #define EOL_UNIX	0	// NL
 #define EOL_DOS		1	// CR NL
 #define EOL_MAC		2	// CR
@@ -570,7 +570,7 @@ EXTERN char_u	*p_fenc;	// 'fileencoding'
 EXTERN char_u	*p_fencs;	// 'fileencodings'
 EXTERN char_u	*p_ff;		// 'fileformat'
 EXTERN char_u	*p_ffs;		// 'fileformats'
-EXTERN long	p_fic;		// 'fileignorecase'
+EXTERN int	p_fic;		// 'fileignorecase'
 EXTERN char_u	*p_ft;		// 'filetype'
 EXTERN char_u	*p_fcs;		// 'fillchar'
 EXTERN int	p_fixeol;	// 'fixendofline'
@@ -750,7 +750,7 @@ EXTERN long	p_mis;		// 'menuitems'
 EXTERN char_u	*p_msm;		// 'mkspellmem'
 #endif
 EXTERN int	p_ml;		// 'modeline'
-EXTERN long	p_mle;		// 'modelineexpr'
+EXTERN int	p_mle;		// 'modelineexpr'
 EXTERN long	p_mls;		// 'modelines'
 EXTERN int	p_ma;		// 'modifiable'
 EXTERN int	p_mod;		// 'modified'
@@ -1078,7 +1078,7 @@ EXTERN int	p_wiv;		// 'weirdinvert'
 EXTERN char_u	*p_ww;		// 'whichwrap'
 EXTERN long	p_wc;		// 'wildchar'
 EXTERN long	p_wcm;		// 'wildcharm'
-EXTERN long	p_wic;		// 'wildignorecase'
+EXTERN int	p_wic;		// 'wildignorecase'
 EXTERN char_u	*p_wim;		// 'wildmode'
 #ifdef FEAT_WILDMENU
 EXTERN int	p_wmnu;		// 'wildmenu'
@@ -1328,6 +1328,6 @@ enum
 };
 
 // Value for b_p_ul indicating the global value must be used.
-#define NO_LOCAL_UNDOLEVEL -123456
+#define NO_LOCAL_UNDOLEVEL (-123456)
 
 #endif // _OPTION_H_

src/proto/drawscreen.pro

@@ -8,7 +8,6 @@ void update_curbuf(int type);
 void update_debug_sign(buf_T *buf, linenr_T lnum);
 void updateWindow(win_T *wp);
 int redraw_asap(int type);
-void check_redraw_cursorline(void);
 void redraw_after_callback(int call_update_screen, int do_message);
 void redraw_later(int type);
 void redraw_win_later(win_T *wp, int type);

src/regexp.h

@@ -31,7 +31,7 @@
  * In the NFA engine: how many states are allowed
  */
 #define NFA_MAX_STATES 100000
-#define NFA_TOO_EXPENSIVE -1
+#define NFA_TOO_EXPENSIVE (-1)
 
 // Which regexp engine to use? Needed for vim_regcomp().
 // Must match with 'regexpengine'.

src/spell.h

@@ -211,9 +211,9 @@ typedef struct salitem_S
 
 // Values for SP_*ERROR are negative, positive values are used by
 // read_cnt_string().
-#define	SP_TRUNCERROR	-1	// spell file truncated error
-#define	SP_FORMERROR	-2	// format error in spell file
-#define SP_OTHERERROR	-3	// other error while reading spell file
+#define	SP_TRUNCERROR	(-1)	// spell file truncated error
+#define	SP_FORMERROR	(-2)	// format error in spell file
+#define SP_OTHERERROR	(-3)	// other error while reading spell file
 
 /*
  * Structure used in "b_langp", filled from 'spelllang'.

src/structs.h

@@ -2830,7 +2830,7 @@ struct file_buffer
     // flags for use of ":lmap" and IM control
     long	b_p_iminsert;	// input mode for insert
     long	b_p_imsearch;	// input mode for search
-#define B_IMODE_USE_INSERT -1	//	Use b_p_iminsert value for search
+#define B_IMODE_USE_INSERT (-1)	//	Use b_p_iminsert value for search
 #define B_IMODE_NONE 0		//	Input via none
 #define B_IMODE_LMAP 1		//	Input via langmap
 #define B_IMODE_IM 2		//	Input via input method
@@ -3698,7 +3698,7 @@ struct window_S
     winopt_T	w_onebuf_opt;
     winopt_T	w_allbuf_opt;
     // transform a pointer to a "onebuf" option into a "allbuf" option
-#define GLOBAL_WO(p)	((char *)p + sizeof(winopt_T))
+#define GLOBAL_WO(p)	((char *)(p) + sizeof(winopt_T))
 
     // A few options have local flags for P_INSECURE.
 #ifdef FEAT_STL_OPT
@@ -4462,7 +4462,7 @@ typedef struct {
 #define FIO_ENCRYPTED	0x1000	// encrypt written bytes
 #define FIO_NOCONVERT	0x2000	// skip encoding conversion
 #define FIO_UCSBOM	0x4000	// check for BOM at start of file
-#define FIO_ALL	-1	// allow all formats
+#define FIO_ALL	(-1)	// allow all formats
 
 // When converting, a read() or write() may leave some bytes to be converted
 // for the next call.  The value is guessed...

src/testdir/dumps/Test_cursorcolumn_callback_1.dump

@@ -0,0 +1,8 @@
+>a+0&#ffffff0@4| @69
+|b+0&#e0e0e08|b+0&#ffffff0@3| @69
+|c+0&#e0e0e08|c+0&#ffffff0@3| @69
+|d+0&#e0e0e08|d+0&#ffffff0@3| @69
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|4|,|5| @10|A|l@1| 

src/testdir/dumps/Test_relativenumber_callback_1.dump

@@ -0,0 +1,8 @@
+| +0#af5f00255#ffffff0@1|0| >a+0#0000000&@4| @65
+| +0#af5f00255&@1|1| |b+0#0000000&@4| @65
+| +0#af5f00255&@1|2| |c+0#0000000&@4| @65
+| +0#af5f00255&@1|3| |d+0#0000000&@4| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|4|,|1| @10|A|l@1| 

src/testdir/test_highlight.vim

@@ -592,6 +592,31 @@ func Test_cursorline_with_visualmode()
   call delete('Xtest_cursorline_with_visualmode')
 endfunc
 
+func Test_cursorcolumn_callback()
+  CheckScreendump
+  CheckFeature timers
+
+  let lines =<< trim END
+      call setline(1, ['aaaaa', 'bbbbb', 'ccccc', 'ddddd'])
+      set cursorcolumn
+      call cursor(4, 5)
+
+      func Func(timer)
+        call cursor(1, 1)
+      endfunc
+
+      call timer_start(300, 'Func')
+  END
+  call writefile(lines, 'Xcuc_timer')
+
+  let buf = RunVimInTerminal('-S Xcuc_timer', #{rows: 8})
+  call TermWait(buf, 310)
+  call VerifyScreenDump(buf, 'Test_cursorcolumn_callback_1', {})
+
+  call StopVimInTerminal(buf)
+  call delete('Xcuc_timer')
+endfunc
+
 func Test_wincolor()
   CheckScreendump
   " make sure the width is enough for the test

src/testdir/test_number.vim

@@ -298,6 +298,31 @@ func Test_relativenumber_colors()
   call delete('XTest_relnr')
 endfunc
 
+func Test_relativenumber_callback()
+  CheckScreendump
+  CheckFeature timers
+
+  let lines =<< trim END
+      call setline(1, ['aaaaa', 'bbbbb', 'ccccc', 'ddddd'])
+      set relativenumber
+      call cursor(4, 1)
+
+      func Func(timer)
+        call cursor(1, 1)
+      endfunc
+
+      call timer_start(300, 'Func')
+  END
+  call writefile(lines, 'Xrnu_timer')
+
+  let buf = RunVimInTerminal('-S Xrnu_timer', #{rows: 8})
+  call TermWait(buf, 310)
+  call VerifyScreenDump(buf, 'Test_relativenumber_callback_1', {})
+
+  call StopVimInTerminal(buf)
+  call delete('Xrnu_timer')
+endfunc
+
 " Test for displaying line numbers with 'rightleft'
 func Test_number_rightleft()
   CheckFeature rightleft

src/testdir/test_vim9_expr.vim

@@ -890,6 +890,93 @@ def Test_expr4_compare_null()
   unlet g:null_dict
   unlet g:not_null_list
 
+  # variables declared at script level used in a :def function
+  lines =<< trim END
+      vim9script
+      
+      var l_decl: list<number>
+      var l_empty = []
+      var l_null = null_list
+
+      def TestList()
+        assert_false(l_decl == null)
+        assert_false(l_decl is null_list)
+        assert_false(l_empty == null)
+        assert_false(l_empty is null_list)
+        assert_true(l_null == null)
+        assert_true(l_null is null_list)
+        assert_true(l_null == null_list)
+
+        add(l_decl, 6)
+        assert_equal([6], l_decl)
+        add(l_empty, 7)
+        assert_equal([7], l_empty)
+        var caught = false
+        try
+          add(l_null, 9)
+        catch /E1130:/
+          caught = true
+        endtry
+        assert_true(caught)
+      enddef
+      TestList()
+      
+      var b_decl: blob
+      var b_empty = 0z
+      var b_null = null_blob
+
+      def TestBlob()
+        assert_false(b_decl == null)
+        assert_false(b_decl is null_blob)
+        assert_false(b_empty == null)
+        assert_false(b_empty is null_blob)
+        assert_true(b_null == null)
+        assert_true(b_null is null_blob)
+        assert_true(b_null == null_blob)
+
+        add(b_decl, 6)
+        assert_equal(0z06, b_decl)
+        add(b_empty, 7)
+        assert_equal(0z07, b_empty)
+        var caught = false
+        try
+          add(b_null, 9)
+        catch /E1131:/
+          caught = true
+        endtry
+        assert_true(caught)
+      enddef
+      TestBlob()
+      
+      var d_decl: dict<number>
+      var d_empty = {}
+      var d_null = null_dict
+
+      def TestDict()
+        assert_false(d_decl == null)
+        assert_false(d_decl is null_dict)
+        assert_false(d_empty == null)
+        assert_false(d_empty is null_dict)
+        assert_true(d_null == null)
+        assert_true(d_null is null_dict)
+        assert_true(d_null == null_dict)
+
+        d_decl['a'] = 6
+        assert_equal({a: 6}, d_decl)
+        d_empty['b'] = 7
+        assert_equal({b: 7}, d_empty)
+        var caught = false
+        try
+          d_null['c'] = 9
+        catch /E1103:/
+          caught = true
+        endtry
+        assert_true(caught)
+      enddef
+      TestDict()
+  END
+  v9.CheckScriptSuccess(lines)
+
   lines =<< trim END
       var d: dict<func> = {f: null_function}
       assert_equal(null_function, d.f)

src/version.c

@@ -750,6 +750,20 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4642,
+/**/
+    4641,
+/**/
+    4640,
+/**/
+    4639,
+/**/
+    4638,
+/**/
+    4637,
+/**/
+    4636,
 /**/
     4635,
 /**/

src/vim.h

@@ -864,9 +864,9 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 #define FINDFILE_DIR	1	// only directories
 #define FINDFILE_BOTH	2	// files and directories
 
-#define W_ENDCOL(wp)	(wp->w_wincol + wp->w_width)
+#define W_ENDCOL(wp)	((wp)->w_wincol + (wp)->w_width)
 #ifdef FEAT_MENU
-# define W_WINROW(wp)	(wp->w_winrow + wp->w_winbar_height)
+# define W_WINROW(wp)	((wp)->w_winrow + (wp)->w_winbar_height)
 #else
 # define W_WINROW(wp)	(wp->w_winrow)
 #endif
@@ -887,7 +887,7 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 # define SST_MAX_ENTRIES 1000	// maximal size for state stack array
 # define SST_FIX_STATES	 7	// size of sst_stack[].
 # define SST_DIST	 16	// normal distance between entries
-# define SST_INVALID	(synstate_T *)-1	// invalid syn_state pointer
+# define SST_INVALID	((synstate_T *)-1)	// invalid syn_state pointer
 
 # define HL_CONTAINED	0x01	// not used on toplevel
 # define HL_TRANSP	0x02	// has no highlighting
@@ -949,7 +949,7 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 #define GETFILE_ERROR	    1	// normal error
 #define GETFILE_NOT_WRITTEN 2	// "not written" error
 #define GETFILE_SAME_FILE   0	// success, same file
-#define GETFILE_OPEN_OTHER -1	// success, opened another file
+#define GETFILE_OPEN_OTHER (-1)	// success, opened another file
 #define GETFILE_UNUSED	    8
 #define GETFILE_SUCCESS(x)  ((x) <= 0)
 
@@ -971,9 +971,9 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 // Values for "noremap" argument of ins_typebuf().  Also used for
 // map->m_noremap and menu->noremap[].
 #define REMAP_YES	0	// allow remapping
-#define REMAP_NONE	-1	// no remapping
-#define REMAP_SCRIPT	-2	// remap script-local mappings only
-#define REMAP_SKIP	-3	// no remapping for first char
+#define REMAP_NONE	(-1)	// no remapping
+#define REMAP_SCRIPT	(-2)	// remap script-local mappings only
+#define REMAP_SKIP	(-3)	// no remapping for first char
 
 // Values for mch_call_shell() second argument
 #define SHELL_FILTER	1	// filtering text
@@ -1069,7 +1069,7 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 
 // for lnum argument in do_ecmd()
 #define ECMD_LASTL	(linenr_T)0	// use last position in loaded file
-#define ECMD_LAST	(linenr_T)-1	// use last position in all files
+#define ECMD_LAST	((linenr_T)-1)	// use last position in all files
 #define ECMD_ONE	(linenr_T)1	// use first line
 
 // flags for do_cmdline()
@@ -1265,13 +1265,13 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 #define MAX_SWAP_PAGE_SIZE 50000
 
 // Special values for current_sctx.sc_sid.
-#define SID_MODELINE	-1	// when using a modeline
-#define SID_CMDARG	-2	// for "--cmd" argument
-#define SID_CARG	-3	// for "-c" argument
-#define SID_ENV		-4	// for sourcing environment variable
-#define SID_ERROR	-5	// option was reset because of an error
-#define SID_NONE	-6	// don't set scriptID
-#define SID_WINLAYOUT	-7	// changing window size
+#define SID_MODELINE	(-1)	// when using a modeline
+#define SID_CMDARG	(-2)	// for "--cmd" argument
+#define SID_CARG	(-3)	// for "-c" argument
+#define SID_ENV		(-4)	// for sourcing environment variable
+#define SID_ERROR	(-5)	// option was reset because of an error
+#define SID_NONE	(-6)	// don't set scriptID
+#define SID_WINLAYOUT	(-7)	// changing window size
 
 /*
  * Events for autocommands.
@@ -1723,7 +1723,7 @@ void *vim_memset(void *, int, size_t);
 // Prefer using emsgf(), because perror() may send the output to the wrong
 // destination and mess up the screen.
 #ifdef HAVE_STRERROR
-# define PERROR(msg)		    (void)semsg("%s: %s", (char *)msg, strerror(errno))
+# define PERROR(msg)		    (void)semsg("%s: %s", (char *)(msg), strerror(errno))
 #else
 # define PERROR(msg)		    do_perror(msg)
 #endif
@@ -1921,7 +1921,7 @@ typedef int sock_T;
     (((unsigned)((code) & 0xC0) >> 6) + 1)
 
 #define SET_NUM_MOUSE_CLICKS(code, num) \
-    (code) = ((code) & 0x3f) | ((((num) - 1) & 3) << 6)
+    ((code) = ((code) & 0x3f) | ((((num) - 1) & 3) << 6))
 
 // Added to mouse column for GUI when 'mousefocus' wants to give focus to a
 // window by simulating a click on its status line.  We could use up to 128 *
@@ -2229,6 +2229,7 @@ typedef enum {
 #define ASSIGN_UNPACK	0x10  // using [a, b] = list
 #define ASSIGN_NO_MEMBER_TYPE 0x20 // use "any" for list and dict member type
 #define ASSIGN_FOR_LOOP 0x40 // assigning to loop variable
+#define ASSIGN_INIT	0x80 // not assigning a value, just a declaration
 
 #include "ex_cmds.h"	    // Ex command defines
 #include "spell.h"	    // spell checking stuff
@@ -2515,8 +2516,8 @@ typedef enum {
 #endif
 
 // values for vim_handle_signal() that are not a signal
-#define SIGNAL_BLOCK	-1
-#define SIGNAL_UNBLOCK  -2
+#define SIGNAL_BLOCK	(-1)
+#define SIGNAL_UNBLOCK  (-2)
 #if !defined(UNIX) && !defined(VMS)
 # define vim_handle_signal(x) 0
 #endif
@@ -2528,8 +2529,8 @@ typedef enum {
 
 // behavior for bad character, "++bad=" argument
 #define BAD_REPLACE	'?'	// replace it with '?' (default)
-#define BAD_KEEP	-1	// leave it
-#define BAD_DROP	-2	// erase it
+#define BAD_KEEP	(-1)	// leave it
+#define BAD_DROP	(-2)	// erase it
 
 // last argument for do_source()
 #define DOSO_NONE	0
@@ -2552,11 +2553,11 @@ typedef enum {
 // direction for nv_mousescroll() and ins_mousescroll()
 #define MSCR_DOWN	0	// DOWN must be FALSE
 #define MSCR_UP		1
-#define MSCR_LEFT	-1
-#define MSCR_RIGHT	-2
+#define MSCR_LEFT	(-1)
+#define MSCR_RIGHT	(-2)
 
-#define KEYLEN_PART_KEY -1	// keylen value for incomplete key-code
-#define KEYLEN_PART_MAP -2	// keylen value for incomplete mapping
+#define KEYLEN_PART_KEY (-1)	// keylen value for incomplete key-code
+#define KEYLEN_PART_MAP (-2)	// keylen value for incomplete mapping
 #define KEYLEN_REMOVED  9999	// keylen value for removed sequence
 
 // Return values from win32_fileinfo().
@@ -2716,8 +2717,8 @@ typedef enum {
 
 #if defined(HAVE_GETTIMEOFDAY) && defined(HAVE_SYS_TIME_H)
 # define ELAPSED_TIMEVAL
-# define ELAPSED_INIT(v) gettimeofday(&v, NULL)
-# define ELAPSED_FUNC(v) elapsed(&v)
+# define ELAPSED_INIT(v) gettimeofday(&(v), NULL)
+# define ELAPSED_FUNC(v) elapsed(&(v))
 typedef struct timeval elapsed_T;
 long elapsed(struct timeval *start_tv);
 #elif defined(MSWIN)
@@ -2734,8 +2735,8 @@ long elapsed(DWORD start_tick);
 #endif
 
 // Replacement for nchar used by nv_replace().
-#define REPLACE_CR_NCHAR    -1
-#define REPLACE_NL_NCHAR    -2
+#define REPLACE_CR_NCHAR    (-1)
+#define REPLACE_NL_NCHAR    (-2)
 
 // flags for term_start()
 #define TERM_START_NOJOB	1

src/vim9.h

@@ -515,10 +515,10 @@ struct dfunc_S {
 extern garray_T def_functions;
 
 // Used for "lnum" when a range is to be taken from the stack.
-#define LNUM_VARIABLE_RANGE -999
+#define LNUM_VARIABLE_RANGE (-999)
 
 // Used for "lnum" when a range is to be taken from the stack and "!" is used.
-#define LNUM_VARIABLE_RANGE_ABOVE -888
+#define LNUM_VARIABLE_RANGE_ABOVE (-888)
 
 // Keep in sync with get_compile_type()
 #ifdef FEAT_PROFILE
@@ -530,7 +530,7 @@ extern garray_T def_functions;
 		: (dfunc)->df_instr))
 #else
 # define INSTRUCTIONS(dfunc) \
-	(debug_break_level > 0 || may_break_in_function(dfunc->df_ufunc) \
+	(debug_break_level > 0 || may_break_in_function((dfunc)->df_ufunc) \
 		? (dfunc)->df_instr_debug \
 		: (dfunc)->df_instr)
 #endif

src/vim9execute.c

@@ -1336,20 +1336,22 @@ do_2string(typval_T *tv, int is_2string_any, int tolerant)
  * When the value of "sv" is a null list of dict, allocate it.
  */
     static void
-allocate_if_null(typval_T *tv)
+allocate_if_null(svar_T *sv)
 {
+    typval_T *tv = sv->sv_tv;
+
     switch (tv->v_type)
     {
 	case VAR_LIST:
-	    if (tv->vval.v_list == NULL)
+	    if (tv->vval.v_list == NULL && sv->sv_type != &t_list_empty)
 		(void)rettv_list_alloc(tv);
 	    break;
 	case VAR_DICT:
-	    if (tv->vval.v_dict == NULL)
+	    if (tv->vval.v_dict == NULL && sv->sv_type != &t_dict_empty)
 		(void)rettv_dict_alloc(tv);
 	    break;
 	case VAR_BLOB:
-	    if (tv->vval.v_blob == NULL)
+	    if (tv->vval.v_blob == NULL && sv->sv_type != &t_blob_null)
 		(void)rettv_blob_alloc(tv);
 	    break;
 	default:
@@ -2891,7 +2893,7 @@ exec_instructions(ectx_T *ectx)
 		    sv = get_script_svar(sref, ectx->ec_dfunc_idx);
 		    if (sv == NULL)
 			goto theend;
-		    allocate_if_null(sv->sv_tv);
+		    allocate_if_null(sv);
 		    if (GA_GROW_FAILS(&ectx->ec_stack, 1))
 			goto theend;
 		    copy_tv(sv->sv_tv, STACK_TV_BOT(0));

src/vim9script.c

@@ -822,7 +822,7 @@ vim9_declare_scriptvar(exarg_T *eap, char_u *arg)
 	init_tv.v_type = VAR_NUMBER;
     else
 	init_tv.v_type = type->tt_type;
-    set_var_const(name, 0, type, &init_tv, FALSE, 0, 0);
+    set_var_const(name, 0, type, &init_tv, FALSE, ASSIGN_INIT, 0);
 
     vim_free(name);
     return p;
@@ -925,6 +925,13 @@ update_vim9_script_var(
 	if (*type == NULL)
 	    *type = typval2type(tv, get_copyID(), &si->sn_type_list,
 					       do_member ? TVTT_DO_MEMBER : 0);
+	else if ((flags & ASSIGN_INIT) == 0
+		&& (*type)->tt_type == VAR_BLOB && tv->v_type == VAR_BLOB
+						    && tv->vval.v_blob == NULL)
+	{
+	    // "var b: blob = null_blob" has a different type.
+	    *type = &t_blob_null;
+	}
 	if (sv->sv_type_allocated)
 	    free_type(sv->sv_type);
 	if (*type != NULL && ((*type)->tt_type == VAR_FUNC

src/vim9type.c

@@ -337,7 +337,11 @@ typval2type_int(typval_T *tv, int copyID, garray_T *type_gap, int flags)
     if (tv->v_type == VAR_STRING)
 	return &t_string;
     if (tv->v_type == VAR_BLOB)
+    {
+	if (tv->vval.v_blob == NULL)
+	    return &t_blob_null;
 	return &t_blob;
+    }
 
     if (tv->v_type == VAR_LIST)
     {