patch 9.1.1666: no support for terminal primary device attributes

Problem:  no support for terminal primary device attributes
Solution: Add support for detecting the DA1 response from the terminal,
          add the v:termda1 variable and the 't_Ms' option for the
          OSC 52 command format (Foxe Chen)

closes: #18033

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 9.1.  Last change: 2025 Aug 20
+*eval.txt*	For Vim version 9.1.  Last change: 2025 Aug 23
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2911,6 +2911,12 @@ v:termu7resp	The escape sequence returned by the terminal for the |t_u7|
 		this option is set, the TermResponseAll autocommand event is
 		fired, with <amatch> set to "ambiguouswidth".
 
+						*v:termda1*
+v:termda1	The escape sequence returned by a primary device attributes
+		(DA1) query from the terminal.  When this option is set, the
+		TermResponseAll autocommand event is fired, with <amatch> set
+		to "da1".  Can be used to detect OSC 52 support in a terminal.
+
 					*v:testing* *testing-variable*
 v:testing	Must be set before using `test_garbagecollect_now()`.
 		Also, when set certain error messages won't be shown for 2

runtime/doc/tags

@@ -1102,6 +1102,7 @@ $quote	eval.txt	/*$quote*
 't_KJ'	term.txt	/*'t_KJ'*
 't_KK'	term.txt	/*'t_KK'*
 't_KL'	term.txt	/*'t_KL'*
+'t_Ms'	term.txt	/*'t_Ms'*
 't_PE'	term.txt	/*'t_PE'*
 't_PS'	term.txt	/*'t_PS'*
 't_RB'	term.txt	/*'t_RB'*
@@ -10587,6 +10588,7 @@ t_KI	term.txt	/*t_KI*
 t_KJ	term.txt	/*t_KJ*
 t_KK	term.txt	/*t_KK*
 t_KL	term.txt	/*t_KL*
+t_Ms	term.txt	/*t_Ms*
 t_PE	term.txt	/*t_PE*
 t_PS	term.txt	/*t_PS*
 t_RB	term.txt	/*t_RB*
@@ -11257,6 +11259,7 @@ v:t_string	eval.txt	/*v:t_string*
 v:t_tuple	eval.txt	/*v:t_tuple*
 v:t_typealias	eval.txt	/*v:t_typealias*
 v:termblinkresp	eval.txt	/*v:termblinkresp*
+v:termda1	eval.txt	/*v:termda1*
 v:termrbgresp	eval.txt	/*v:termrbgresp*
 v:termresponse	eval.txt	/*v:termresponse*
 v:termrfgresp	eval.txt	/*v:termrfgresp*

runtime/doc/term.txt

@@ -1,4 +1,4 @@
-*term.txt*      For Vim version 9.1.  Last change: 2025 Aug 06
+*term.txt*      For Vim version 9.1.  Last change: 2025 Aug 23
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -644,6 +644,9 @@ Note: Use the <> form if possible
 		<FocusGained>	Vim window got focus (internal only)
 		<FocusLost>	Vim window lost focus (internal only)
 
+	t_Ms			OSC 52 command format (empty	*t_Ms* *'t_Ms'*
+				if terminal doesn't support it)
+
 Note about t_so and t_mr: When the termcap entry "so" is not present the
 entry for "mr" is used.  And vice versa.  The same is done for "se" and "me".
 If your terminal supports both inversion and standout mode, you can see two

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Aug 22
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Aug 23
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41851,12 +41851,17 @@ Options: ~
 'tabpanelopt'		Optional settings for the |tabpanel|
 't_xo'			Terminal uses XON/XOFF handshaking (e.g. vt420)
 't_CF'			Support for alternate font highlighting terminal code
+'t_Ms'			OSC 52 command format
 'winfixbuf'		Keep buffer focused in a window
 'wlseat'		Specify Wayland seat to use for the |wayland| feature
 'wlsteal'		Steal focus to access the |wayland| clipboard
 'wltimeout'		Specify the connection timeout for the |wayland|
 			compositor
 
+Vim Variables: ~
+|v:termda1|		The escape sequence returned for the primary device
+			attribute query (DA1).
+
 Vim Arguments: ~
 |-Y|			Do not connect to the |wayland| compositor.
 |--clientserver|	Specify backend for clientserver functionality.

runtime/syntax/vim.vim

@@ -2,7 +2,7 @@
 " Language:	   Vim script
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
-" Last Change:	   2025 Aug 18
+" Last Change:	   2025 Aug 23
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -165,7 +165,7 @@ syn keyword vimFuncName contained win_getid win_gettype win_gotoid win_id2tabwin
 " Predefined variable names {{{2
 " GEN_SYN_VIM: vimVarName, START_STR='syn keyword vimVimVarName contained', END_STR=''
 syn keyword vimVimVarName contained count count1 prevcount errmsg warningmsg statusmsg shell_error this_session version lnum termresponse fname lang lc_time ctype charconvert_from charconvert_to fname_in fname_out fname_new fname_diff cmdarg foldstart foldend folddashes foldlevel progname servername dying exception throwpoint register cmdbang insertmode val key profiling fcs_reason fcs_choice beval_bufnr beval_winnr beval_winid beval_lnum beval_col beval_text scrollstart swapname swapchoice swapcommand char mouse_win mouse_winid mouse_lnum mouse_col operator searchforward hlsearch oldfiles windowid progpath completed_item option_new option_old option_oldlocal option_oldglobal option_command option_type errors false true none null numbermax numbermin numbersize
-syn keyword vimVimVarName contained vim_did_enter testing t_number t_string t_func t_list t_dict t_float t_bool t_none t_job t_channel t_blob t_class t_object termrfgresp termrbgresp termu7resp termstyleresp termblinkresp event versionlong echospace argv collate exiting colornames sizeofint sizeoflong sizeofpointer maxcol python3_version t_typealias t_enum t_enumvalue stacktrace t_tuple wayland_display clipmethod
+syn keyword vimVimVarName contained vim_did_enter testing t_number t_string t_func t_list t_dict t_float t_bool t_none t_job t_channel t_blob t_class t_object termrfgresp termrbgresp termu7resp termstyleresp termblinkresp event versionlong echospace argv collate exiting colornames sizeofint sizeoflong sizeofpointer maxcol python3_version t_typealias t_enum t_enumvalue stacktrace t_tuple wayland_display clipmethod termda1
 
 "--- syntax here and above generated by runtime/syntax/generator/gen_syntax_vim.vim ---
 

src/evalvars.c

@@ -165,6 +165,7 @@ static struct vimvar
     {VV_NAME("t_tuple",		 VAR_NUMBER), NULL, VV_RO},
     {VV_NAME("wayland_display",  VAR_STRING), NULL, VV_RO},
     {VV_NAME("clipmethod",	 VAR_STRING), NULL, VV_RO},
+    {VV_NAME("termda1",		 VAR_STRING), NULL, VV_RO},
 };
 
 // shorthand

src/term.c

@@ -1719,7 +1719,7 @@ static char *(key_names[]) =
     "k7", "k8", "k9", "k;", "F1", "F2",
     "%1", "&8", "kb", "kI", "kD", "kh",
     "@7", "kP", "kN", "K1", "K3", "K4", "K5", "kB",
-    "PS", "PE",
+    "PS", "PE", "Ms",
     NULL
 };
 #endif
@@ -5495,6 +5495,8 @@ handle_csi_function_key(
  *	{lead}[ABCDEFHPQRS]
  *	{lead}1;{modifier}[ABCDEFHPQRS]
  *
+ * - DA1 query response: {lead}?...;c
+ *
  * Return 0 for no match, -1 for partial match, > 0 for full match.
  */
     static int
@@ -5607,6 +5609,22 @@ handle_csi(
 	*slen = csi_len;
     }
 
+    // Primary device attributes (DA1) response
+    else if (first == '?' && trail == 'c')
+    {
+	LOG_TRN("Received DA1 response: %s", tp);
+
+	*slen = csi_len;
+#ifdef FEAT_EVAL
+	set_vim_var_string(VV_TERMDA1, tp, *slen);
+#endif
+	apply_autocmds(EVENT_TERMRESPONSEALL,
+					(char_u *)"da1", NULL, FALSE, curbuf);
+
+	key_name[0] = (int)KS_EXTRA;
+	key_name[1] = (int)KE_IGNORE;
+    }
+
     // Version string: Eat it when there is at least one digit and
     // it ends in 'c'
     else if (*T_CRV != NUL && ap > argp + 1 && trail == 'c')

src/testdir/test_termcodes.vim

@@ -2803,4 +2803,9 @@ func Test_xterm_direct_no_termguicolors()
   close
 endfunc
 
+func Test_da1_handling()
+  call feedkeys("\<Esc>[?62,52;c", 'Lx!')
+  call assert_equal("\<Esc>[?62,52;c", v:termda1)
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1666,
 /**/
     1665,
 /**/

src/vim.h

@@ -2239,7 +2239,8 @@ typedef int sock_T;
 #define VV_TYPE_TUPLE	111
 #define VV_WAYLAND_DISPLAY 112
 #define VV_CLIPMETHOD 113
-#define VV_LEN		114	// number of v: vars
+#define VV_TERMDA1 114
+#define VV_LEN		115	// number of v: vars
 
 // used for v_number in VAR_BOOL and VAR_SPECIAL
 #define VVAL_FALSE	0L	// VAR_BOOL