patch 8.1.1366: using expressions in a modeline is unsafe

Problem:    Using expressions in a modeline is unsafe.
Solution:   Disallow using expressions in a modeline, unless the
            'modelineexpr' option is set.  Update help, add more tests.

runtime/doc/options.txt

@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 8.1.  Last change: 2019 May 08
+*options.txt*	For Vim version 8.1.  Last change: 2019 May 23
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -578,14 +578,17 @@ backslash in front of the ':' will be removed.  Example:
    /* vi:set dir=c\:\tmp: */ ~
 This sets the 'dir' option to "c:\tmp".  Only a single backslash before the
 ':' is removed.  Thus to include "\:" you have to specify "\\:".
-
+							*E992*
 No other commands than "set" are supported, for security reasons (somebody
 might create a Trojan horse text file with modelines).  And not all options
-can be set.  For some options a flag is set, so that when it's used the
+can be set.  For some options a flag is set, so that when the value is used
-|sandbox| is effective.  Still, there is always a small risk that a modeline
+the |sandbox| is effective.  Some options can only be set from the modeline
-causes trouble.  E.g., when some joker sets 'textwidth' to 5 all your lines
+when 'modelineexpr' is set (the default is off).
-are wrapped unexpectedly.  So disable modelines before editing untrusted text.
+
-The mail ftplugin does this, for example.
+Still, there is always a small risk that a modeline causes trouble.  E.g.,
+when some joker sets 'textwidth' to 5 all your lines are wrapped unexpectedly.
+So disable modelines before editing untrusted text.  The mail ftplugin does
+this, for example.
 
 Hint: If you would like to do something else than setting an option, you could
 define an autocommand that checks the file for a specific string.  For
@@ -1149,6 +1152,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'balloonexpr' |textlock|.
@@ -3226,7 +3230,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	The expression will be evaluated in the |sandbox| if set from a
 	modeline, see |sandbox-option|.
 	This option can't be set from a |modeline| when the 'diff' option is
-	on.
+	on or the 'modelineexpr' option is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'foldexpr' |textlock|.
@@ -3359,6 +3363,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	The expression will be evaluated in the |sandbox| if set from a
 	modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'foldtext' |textlock|.
@@ -3396,6 +3401,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.  That stops the option from working,
 	since changing the buffer text is not allowed.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 	NOTE: This option is set to "" when 'compatible' is set.
 
 					*'formatlistpat'* *'flp'*
@@ -3452,6 +3458,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	Also see 'swapsync' for controlling fsync() on swap files.
 	'fsync' also applies to |writefile()|, unless a flag is used to
 	overrule it.
+	This option cannot be set from a |modeline| or in the |sandbox|, for
+	security reasons.
 
 				   *'gdefault'* *'gd'* *'nogdefault'* *'nogd'*
 'gdefault' 'gd'		boolean	(default off)
@@ -3619,7 +3627,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 						*'guiheadroom'* *'ghr'*
 'guiheadroom' 'ghr'	number	(default 50)
 			global
-- 			{only for GTK and X11 GUI}
+			{only for GTK and X11 GUI}
 	The number of pixels subtracted from the screen height when fitting
 	the GUI window on the screen.  Set this before the GUI is started,
 	e.g., in your |gvimrc| file.  When zero, the whole screen height will
@@ -3777,6 +3785,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	'guitabtooltip' is used for the tooltip, see below.
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	Only used when the GUI tab pages line is displayed.  'e' must be
 	present in 'guioptions'.  For the non-GUI tab pages line 'tabline' is
@@ -4027,6 +4036,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 	When this option contains printf-style '%' items, they will be
 	expanded according to the rules used for 'statusline'.  See
 	'titlestring' for example settings.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 	{not available when compiled without the |+statusline| feature}
 
 			*'ignorecase'* *'ic'* *'noignorecase'* *'noic'*
@@ -4044,6 +4054,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	This option specifies a function that will be called to
 	activate or deactivate the Input Method.
 	It is not used in the GUI.
+	The expression will be evaluated in the |sandbox| when set from a
+	modeline, see |sandbox-option|.
 
 	Example: >
 		function ImActivateFunc(active)
@@ -4160,6 +4172,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 		set imstatusfunc=ImStatusFunc
 <
 	NOTE: This function is invoked very often.  Keep it fast.
+	The expression will be evaluated in the |sandbox| when set from a
+	modeline, see |sandbox-option|.
 
 						*'imstyle'* *'imst'*
 'imstyle' 'imst'	number (default 1)
@@ -4176,6 +4190,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	|single-repeat|, etc.  Therefore over-the-spot style becomes the
 	default now.  This should work fine for most people, however if you
 	have any problem with it, try using on-the-spot style.
+	The expression will be evaluated in the |sandbox| when set from a
+	modeline, see |sandbox-option|.
 
 						*'include'* *'inc'*
 'include' 'inc'		string	(default "^\s*#\s*include")
@@ -4210,6 +4226,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'includeexpr' |textlock|.
@@ -4297,6 +4314,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	The expression will be evaluated in the |sandbox| when set from a
 	modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'indentexpr' |textlock|.
@@ -4893,6 +4911,12 @@ A jump table for the options with a short description can be found at |Q_op|.
 <	This option cannot be set from a |modeline| or in the |sandbox|, for
 	security reasons.
 
+						*'makespellmem'* *'msm'*
+'makespellmem' 'msm'		string	(default "460000,2000,500")
+			global
+	Values relevant only when compressing a spell file, see |spell|.
+	This option cannot be set from a |modeline| or in the |sandbox|.
+
 						*'matchpairs'* *'mps'*
 'matchpairs' 'mps'	string	(default "(:),{:},[:]")
 			local to buffer
@@ -4915,7 +4939,6 @@ A jump table for the options with a short description can be found at |Q_op|.
 						*'matchtime'* *'mat'*
 'matchtime' 'mat'	number	(default 5)
 			global
-			{in Nvi}
 	Tenths of a second to show the matching paren, when 'showmatch' is
 	set.  Note that this is not in milliseconds, like other options that
 	set a time.  This is to be compatible with Nvi.
@@ -5049,6 +5072,17 @@ A jump table for the options with a short description can be found at |Q_op|.
 'modeline' 'ml'		boolean	(Vim default: on (off for root),
 				 Vi default: off)
 			local to buffer
+	If 'modeline' is on 'modelines' gives the number of lines that is
+	checked for set commands.  If 'modeline' is off or 'modelines' is zero
+	no lines are checked.  See |modeline|.
+
+			   *'modelineexpr'* *'mle'* *'nomodelineexpr'* *'nomle'*
+'modelineexpr' 'mle'	boolean (default: off)
+			global
+	When on allow some options that are an expression to be set in the
+	modeline.  Check the option for whether it is affected by
+	'modelineexpr'.  Also see |modeline|.
+
 						*'modelines'* *'mls'*
 'modelines' 'mls'	number	(default 5)
 			global
@@ -5059,9 +5093,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	set and to the Vim default value when 'compatible' is reset.
 
 				*'modifiable'* *'ma'* *'nomodifiable'* *'noma'*
+				*E21*
 'modifiable' 'ma'	boolean	(default on)
 			local to buffer
-			*E21*
 	When off the buffer contents cannot be changed.  The 'fileformat' and
 	'fileencoding' options also can't be changed.
 	Can be reset on startup with the |-M| command line argument.
@@ -6058,6 +6092,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	When this option is not empty, it determines the content of the ruler
 	string, as displayed for the 'ruler' option.
 	The format of this option is like that of 'statusline'.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
+
 	The default ruler width is 17 characters.  To make the ruler 15
 	characters wide, put "%15(" at the start and "%)" at the end.
 	Example: >
@@ -6598,7 +6634,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 		"Pattern not found", "Back at original", etc.
 	  q	use "recording" instead of "recording @a"
 	  F	don't give the file info when editing a file, like `:silent`
-		was used for the command
+		was used for the command; note that this also affects messages
+		from autocommands
 	  S     do not show search count message when searching, e.g.
 	        "[1/5]"
 
@@ -7165,6 +7202,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	The 'statusline' option will be evaluated in the |sandbox| if set from
 	a modeline, see |sandbox-option|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	It is not allowed to change text or jump to another window while
 	evaluating 'statusline' |textlock|.
@@ -7345,6 +7383,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	When changing something that is used in 'tabline' that does not
 	trigger it to be updated, use |:redrawtabline|.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
 
 	Keep in mind that only one of the tab pages is the current one, others
 	are invisible and you can't jump to their windows.
@@ -7873,8 +7912,11 @@ A jump table for the options with a short description can be found at |Q_op|.
 	non-empty 't_ts' option).
 	When Vim was compiled with HAVE_X11 defined, the original title will
 	be restored if possible, see |X11|.
+
 	When this option contains printf-style '%' items, they will be
 	expanded according to the rules used for 'statusline'.
+	This option cannot be set in a modeline when 'modelineexpr' is off.
+
 	Example: >
     :auto BufEnter * let &titlestring = hostname() . "/" . expand("%:p")
     :set title titlestring=%<%F%=%l/%L-%P titlelen=70
@@ -8060,6 +8102,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	undo file that exists is used.  When it cannot be read an error is
 	given, no further entry is used.
 	See |undo-persistence|.
+	This option cannot be set from a |modeline| or in the |sandbox|, for
+	security reasons.
 
 				*'undofile'* *'noundofile'* *'udf'* *'noudf'*
 'undofile' 'udf'	boolean	(default off)
@@ -8369,6 +8413,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	When equal to "NONE" no viminfo file will be read or written.
 	This option can be set with the |-i| command line flag.  The |--clean|
 	command line flag sets it to "NONE".
+	This option cannot be set from a |modeline| or in the |sandbox|, for
+	security reasons.
 
 					    *'virtualedit'* *'ve'*
 'virtualedit' 've'	string	(default "")

src/option.c

@@ -467,6 +467,7 @@ struct vimoption
 				  * there is a redraw flag */
 #define P_NDNAME      0x8000000L /* only normal dir name chars allowed */
 #define P_RWINONLY   0x10000000L /* only redraw current window */
+#define P_MLE	     0x20000000L /* under control of 'modelineexpr' */
 
 #define ISK_LATIN1  (char_u *)"@,48-57,_,192-255"
 
@@ -650,7 +651,7 @@ static struct vimoption options[] =
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"balloonexpr", "bexpr", P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"balloonexpr", "bexpr", P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #if defined(FEAT_BEVAL) && defined(FEAT_EVAL)
 			    (char_u *)&p_bexpr, PV_BEXPR,
 			    {(char_u *)"", (char_u *)0L}
@@ -727,7 +728,7 @@ static struct vimoption options[] =
 			    (char_u *)&p_cmp, PV_NONE,
 			    {(char_u *)"internal,keepascii", (char_u *)0L}
 			    SCTX_INIT},
-    {"cdpath",	    "cd",   P_STRING|P_EXPAND|P_VI_DEF|P_COMMA|P_NODUP,
+    {"cdpath",	    "cd",   P_STRING|P_EXPAND|P_VI_DEF|P_SECURE|P_COMMA|P_NODUP,
 #ifdef FEAT_SEARCHPATH
 			    (char_u *)&p_cdpath, PV_NONE,
 			    {(char_u *)",,", (char_u *)0L}
@@ -1175,7 +1176,7 @@ static struct vimoption options[] =
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"foldexpr",    "fde",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN,
+    {"foldexpr",    "fde",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_FOLDING) && defined(FEAT_EVAL)
 			    (char_u *)VAR_WIN, PV_FDE,
 			    {(char_u *)"0", (char_u *)NULL}
@@ -1258,7 +1259,7 @@ static struct vimoption options[] =
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"foldtext",    "fdt",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN,
+    {"foldtext",    "fdt",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_FOLDING) && defined(FEAT_EVAL)
 			    (char_u *)VAR_WIN, PV_FDT,
 			    {(char_u *)"foldtext()", (char_u *)NULL}
@@ -1267,7 +1268,7 @@ static struct vimoption options[] =
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"formatexpr", "fex",   P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"formatexpr", "fex",   P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #ifdef FEAT_EVAL
 			    (char_u *)&p_fex, PV_FEX,
 			    {(char_u *)"", (char_u *)0L}
@@ -1406,7 +1407,7 @@ static struct vimoption options[] =
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)TRUE, (char_u *)0L} SCTX_INIT},
-    {"guitablabel",  "gtl", P_STRING|P_VI_DEF|P_RWIN,
+    {"guitablabel",  "gtl", P_STRING|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_GUI_TABLINE)
 			    (char_u *)&p_gtl, PV_NONE,
 			    {(char_u *)"", (char_u *)0L}
@@ -1477,7 +1478,7 @@ static struct vimoption options[] =
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"iconstring",  NULL,   P_STRING|P_VI_DEF,
+    {"iconstring",  NULL,   P_STRING|P_VI_DEF|P_MLE,
 #ifdef FEAT_TITLE
 			    (char_u *)&p_iconstring, PV_NONE,
 #else
@@ -1549,7 +1550,7 @@ static struct vimoption options[] =
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"includeexpr", "inex", P_STRING|P_ALLOCED|P_VI_DEF,
+    {"includeexpr", "inex", P_STRING|P_ALLOCED|P_VI_DEF|P_MLE,
 #if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
 			    (char_u *)&p_inex, PV_INEX,
 			    {(char_u *)"", (char_u *)0L}
@@ -1561,7 +1562,7 @@ static struct vimoption options[] =
     {"incsearch",   "is",   P_BOOL|P_VI_DEF|P_VIM,
 			    (char_u *)&p_is, PV_NONE,
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"indentexpr", "inde",  P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"indentexpr", "inde",  P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
 			    (char_u *)&p_inde, PV_INDE,
 			    {(char_u *)"", (char_u *)0L}
@@ -1888,6 +1889,9 @@ static struct vimoption options[] =
     {"modeline",    "ml",   P_BOOL|P_VIM,
 			    (char_u *)&p_ml, PV_ML,
 			    {(char_u *)FALSE, (char_u *)TRUE} SCTX_INIT},
+    {"modelineexpr", "mle",  P_BOOL|P_VI_DEF,
+			    (char_u *)&p_mle, PV_NONE,
+			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
     {"modelines",   "mls",  P_NUM|P_VI_DEF,
 			    (char_u *)&p_mls, PV_NONE,
 			    {(char_u *)5L, (char_u *)0L} SCTX_INIT},
@@ -2311,7 +2315,7 @@ static struct vimoption options[] =
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"rulerformat", "ruf",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT,
+    {"rulerformat", "ruf",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_ruf, PV_NONE,
 #else
@@ -2577,7 +2581,7 @@ static struct vimoption options[] =
     {"startofline", "sol",  P_BOOL|P_VI_DEF|P_VIM,
 			    (char_u *)&p_sol, PV_NONE,
 			    {(char_u *)TRUE, (char_u *)0L} SCTX_INIT},
-    {"statusline"  ,"stl",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT,
+    {"statusline"  ,"stl",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_stl, PV_STL,
 #else
@@ -2624,7 +2628,7 @@ static struct vimoption options[] =
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"tabline",	    "tal",  P_STRING|P_VI_DEF|P_RALL,
+    {"tabline",	    "tal",  P_STRING|P_VI_DEF|P_RALL|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_tal, PV_NONE,
 #else
@@ -2802,7 +2806,7 @@ static struct vimoption options[] =
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"titlestring", NULL,   P_STRING|P_VI_DEF,
+    {"titlestring", NULL,   P_STRING|P_VI_DEF|P_MLE,
 #ifdef FEAT_TITLE
 			    (char_u *)&p_titlestring, PV_NONE,
 #else
@@ -4549,6 +4553,11 @@ do_set(
 		    errmsg = _("E520: Not allowed in a modeline");
 		    goto skip;
 		}
+		if ((flags & P_MLE) && !p_mle)
+		{
+		    errmsg = _("E992: Not allowed in a modeline when 'modelineexpr' is off");
+		    goto skip;
+		}
 #ifdef FEAT_DIFF
 		/* In diff mode some options are overruled.  This avoids that
 		 * 'foldmethod' becomes "marker" instead of "diff" and that

src/option.h

@@ -631,6 +631,7 @@ EXTERN long	p_mis;		/* 'menuitems' */
 #ifdef FEAT_SPELL
 EXTERN char_u	*p_msm;		/* 'mkspellmem' */
 #endif
+EXTERN long	p_mle;		/* 'modelineexpr' */
 EXTERN long	p_mls;		/* 'modelines' */
 EXTERN char_u	*p_mouse;	/* 'mouse' */
 #ifdef FEAT_GUI

src/testdir/test49.in

@@ -5,7 +5,7 @@ test49.failed, try to add one or more "G"s at the line ending in "test.out"
 
 STARTTEST
 :so small.vim
-:se nocp nomore viminfo+=nviminfo
+:se nocp nomore viminfo+=nviminfo modelineexpr
 :lang mess C
 :so test49.vim
 :" Go back to this file and append the results from register r.

src/testdir/test_modeline.vim

@@ -60,14 +60,17 @@ func Test_modeline_keymap()
   set keymap= iminsert=0 imsearch=-1
 endfunc
 
-func s:modeline_fails(what, text)
+func s:modeline_fails(what, text, error)
+  if !exists('+' .. a:what)
+    return
+  endif
   let fname = "Xmodeline_fails_" . a:what
   call writefile(['vim: set ' . a:text . ' :', 'nothing'], fname)
   let modeline = &modeline
   set modeline
   filetype plugin on
   syntax enable
-  call assert_fails('split ' . fname, 'E474:')
+  call assert_fails('split ' . fname, a:error)
   call assert_equal("", &filetype)
   call assert_equal("", &syntax)
 
@@ -79,16 +82,90 @@ func s:modeline_fails(what, text)
 endfunc
 
 func Test_modeline_filetype_fails()
-  call s:modeline_fails('filetype', 'ft=evil$CMD')
+  call s:modeline_fails('filetype', 'ft=evil$CMD', 'E474:')
 endfunc
 
 func Test_modeline_syntax_fails()
-  call s:modeline_fails('syntax', 'syn=evil$CMD')
+  call s:modeline_fails('syntax', 'syn=evil$CMD', 'E474:')
 endfunc
 
 func Test_modeline_keymap_fails()
-  if !has('keymap')
+  call s:modeline_fails('keymap', 'keymap=evil$CMD', 'E474:')
-    return
+endfunc
-  endif
+
-  call s:modeline_fails('keymap', 'keymap=evil$CMD')
+func Test_modeline_fails_always()
+  call s:modeline_fails('backupdir', 'backupdir=Something()', 'E520:')
+  call s:modeline_fails('cdpath', 'cdpath=Something()', 'E520:')
+  call s:modeline_fails('charconvert', 'charconvert=Something()', 'E520:')
+  call s:modeline_fails('completefunc', 'completefunc=Something()', 'E520:')
+  call s:modeline_fails('cscopeprg', 'cscopeprg=Something()', 'E520:')
+  call s:modeline_fails('diffexpr', 'diffexpr=Something()', 'E520:')
+  call s:modeline_fails('directory', 'directory=Something()', 'E520:')
+  call s:modeline_fails('equalprg', 'equalprg=Something()', 'E520:')
+  call s:modeline_fails('errorfile', 'errorfile=Something()', 'E520:')
+  call s:modeline_fails('exrc', 'exrc=Something()', 'E520:')
+  call s:modeline_fails('formatprg', 'formatprg=Something()', 'E520:')
+  call s:modeline_fails('fsync', 'fsync=Something()', 'E520:')
+  call s:modeline_fails('grepprg', 'grepprg=Something()', 'E520:')
+  call s:modeline_fails('helpfile', 'helpfile=Something()', 'E520:')
+  call s:modeline_fails('imactivatefunc', 'imactivatefunc=Something()', 'E520:')
+  call s:modeline_fails('imstatusfunc', 'imstatusfunc=Something()', 'E520:')
+  call s:modeline_fails('imstyle', 'imstyle=Something()', 'E520:')
+  call s:modeline_fails('keywordprg', 'keywordprg=Something()', 'E520:')
+  call s:modeline_fails('langmap', 'langmap=Something()', 'E520:')
+  call s:modeline_fails('luadll', 'luadll=Something()', 'E520:')
+  call s:modeline_fails('makeef', 'makeef=Something()', 'E520:')
+  call s:modeline_fails('makeprg', 'makeprg=Something()', 'E520:')
+  call s:modeline_fails('makespellmem', 'makespellmem=Something()', 'E520:')
+  call s:modeline_fails('mzschemedll', 'mzschemedll=Something()', 'E520:')
+  call s:modeline_fails('mzschemegcdll', 'mzschemegcdll=Something()', 'E520:')
+  call s:modeline_fails('omnifunc', 'omnifunc=Something()', 'E520:')
+  call s:modeline_fails('operatorfunc', 'operatorfunc=Something()', 'E520:')
+  call s:modeline_fails('perldll', 'perldll=Something()', 'E520:')
+  call s:modeline_fails('printdevice', 'printdevice=Something()', 'E520:')
+  call s:modeline_fails('patchexpr', 'patchexpr=Something()', 'E520:')
+  call s:modeline_fails('printexpr', 'printexpr=Something()', 'E520:')
+  call s:modeline_fails('pythondll', 'pythondll=Something()', 'E520:')
+  call s:modeline_fails('pythonhome', 'pythondll=Something()', 'E520:')
+  call s:modeline_fails('pythonthreedll', 'pythonthreedll=Something()', 'E520:')
+  call s:modeline_fails('pythonthreehome', 'pythonthreehome=Something()', 'E520:')
+  call s:modeline_fails('pyxversion', 'pyxversion=Something()', 'E520:')
+  call s:modeline_fails('rubydll', 'rubydll=Something()', 'E520:')
+  call s:modeline_fails('runtimepath', 'runtimepath=Something()', 'E520:')
+  call s:modeline_fails('secure', 'secure=Something()', 'E520:')
+  call s:modeline_fails('shell', 'shell=Something()', 'E520:')
+  call s:modeline_fails('shellcmdflag', 'shellcmdflag=Something()', 'E520:')
+  call s:modeline_fails('shellpipe', 'shellpipe=Something()', 'E520:')
+  call s:modeline_fails('shellquote', 'shellquote=Something()', 'E520:')
+  call s:modeline_fails('shellredir', 'shellredir=Something()', 'E520:')
+  call s:modeline_fails('shellxquote', 'shellxquote=Something()', 'E520:')
+  call s:modeline_fails('spellfile', 'spellfile=Something()', 'E520:')
+  call s:modeline_fails('spellsuggest', 'spellsuggest=Something()', 'E520:')
+  call s:modeline_fails('tcldll', 'tcldll=Something()', 'E520:')
+  call s:modeline_fails('titleold', 'titleold=Something()', 'E520:')
+  call s:modeline_fails('viewdir', 'viewdir=Something()', 'E520:')
+  call s:modeline_fails('viminfo', 'viminfo=Something()', 'E520:')
+  call s:modeline_fails('viminfofile', 'viminfofile=Something()', 'E520:')
+  call s:modeline_fails('winptydll', 'winptydll=Something()', 'E520:')
+  call s:modeline_fails('undodir', 'undodir=Something()', 'E520:')
+  " only check a few terminal options
+  call s:modeline_fails('t_AB', 't_AB=Something()', 'E520:')
+  call s:modeline_fails('t_ce', 't_ce=Something()', 'E520:')
+  call s:modeline_fails('t_sr', 't_sr=Something()', 'E520:')
+  call s:modeline_fails('t_8b', 't_8b=Something()', 'E520:')
+endfunc
+
+func Test_modeline_fails_modelineexpr()
+  call s:modeline_fails('balloonexpr', 'balloonexpr=Something()', 'E992:')
+  call s:modeline_fails('foldexpr', 'foldexpr=Something()', 'E992:')
+  call s:modeline_fails('foldtext', 'foldtext=Something()', 'E992:')
+  call s:modeline_fails('formatexpr', 'formatexpr=Something()', 'E992:')
+  call s:modeline_fails('guitablabel', 'guitablabel=Something()', 'E992:')
+  call s:modeline_fails('iconstring', 'iconstring=Something()', 'E992:')
+  call s:modeline_fails('includeexpr', 'includeexpr=Something()', 'E992:')
+  call s:modeline_fails('indentexpr', 'indentexpr=Something()', 'E992:')
+  call s:modeline_fails('rulerformat', 'rulerformat=Something()', 'E992:')
+  call s:modeline_fails('statusline', 'statusline=Something()', 'E992:')
+  call s:modeline_fails('tabline', 'tabline=Something()', 'E992:')
+  call s:modeline_fails('titlestring', 'titlestring=Something()', 'E992:')
 endfunc

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1366,
 /**/
     1365,
 /**/