patch 9.1.1932: OSC terminal response hard to detect

Problem:  OSC terminal response hard to detect
Solution: Add the <OSC> and <xOSC> pseudo keys
          (Foxe Chen).

related: #18660
closes: #18799

Signed-off-by: Foxe Chen <[email protected]>
Signed-off-by: Christian Brabandt <[email protected]>

Author: 64-bitman

runtime/doc/intro.txt

@@ -1,4 +1,4 @@
-*intro.txt*	For Vim version 9.1.  Last change: 2025 Nov 09
+*intro.txt*	For Vim version 9.1.  Last change: 2025 Nov 27
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -450,6 +450,8 @@ notation	meaning		    equivalent	decimal value(s)	~
 <Del>		delete				127
 <CSI>		command sequence intro  ALT-Esc 155	*<CSI>*
 <xCSI>		CSI when typed in the GUI		*<xCSI>*
+<OSC>		operating system command	157	*<OSC>*
+<xOSC>		received OSC response			*<xOSC>*
 
 <EOL>		end-of-line (can be <CR>, <NL> or <CR><NL>,
 		depends on system and 'fileformat')	*<EOL>*

runtime/doc/tags

@@ -3841,6 +3841,7 @@ $quote	eval.txt	/*$quote*
 <NL>	motion.txt	/*<NL>*
 <Nop>	map.txt	/*<Nop>*
 <Nul>	intro.txt	/*<Nul>*
+<OSC>	intro.txt	/*<OSC>*
 <PageDown>	scroll.txt	/*<PageDown>*
 <PageUp>	scroll.txt	/*<PageUp>*
 <Plug>	map.txt	/*<Plug>*
@@ -3961,6 +3962,7 @@ $quote	eval.txt	/*$quote*
 <xHome>	term.txt	/*<xHome>*
 <xHome>-xterm	term.txt	/*<xHome>-xterm*
 <xLeft>	term.txt	/*<xLeft>*
+<xOSC>	intro.txt	/*<xOSC>*
 <xRight>	term.txt	/*<xRight>*
 <xUp>	term.txt	/*<xUp>*
 =	change.txt	/*=*

src/evalfunc.c

@@ -5150,7 +5150,9 @@ f_feedkeys(typval_T *argvars, typval_T *rettv UNUSED)
 		++ex_normal_busy;
 		++in_feedkeys;
 	    }
+	    ++allow_osc_key;
 	    exec_normal(TRUE, lowlevel, TRUE);
+	    --allow_osc_key;
 	    if (!dangerous)
 	    {
 		--ex_normal_busy;

src/getchar.c

@@ -1977,6 +1977,9 @@ vgetc(void)
 		}
 		c = TO_SPECIAL(c2, c);
 
+		if (allow_osc_key == 0 && c == K_OSC)
+		    continue;
+
 		// K_ESC is used to avoid ambiguity with the single Esc
 		// character that might be the start of an escape sequence.
 		// Convert it back to a single Esc here.
@@ -2452,6 +2455,7 @@ getchar_common(typval_T *argvars, typval_T *rettv, int allow_number)
 
     ++no_mapping;
     ++allow_keys;
+    ++allow_osc_key;
     if (!simplify)
 	++no_reduce_keys;
     for (;;)
@@ -2479,6 +2483,7 @@ getchar_common(typval_T *argvars, typval_T *rettv, int allow_number)
     }
     --no_mapping;
     --allow_keys;
+    --allow_osc_key;
     if (!simplify)
 	--no_reduce_keys;
 

src/globals.h

@@ -2124,3 +2124,6 @@ INIT(= CLIENTSERVER_METHOD_NONE);
 // Path to socket of last client that communicated with us
 EXTERN char_u *client_socket INIT(= NULL);
 #endif
+
+// If the <xOSC> key should be propogated from vgetc()
+EXTERN int allow_osc_key INIT(= 0);

src/keymap.h

@@ -280,6 +280,7 @@ enum key_extra
     , KE_SID = 106		// <SID> special key, followed by {nr};
     , KE_ESC = 107		// used for K_ESC
     , KE_WILD = 108		// triggers wildmode completion
+    , KE_OSC = 109		// finished OSC sequence
 };
 
 /*
@@ -478,6 +479,7 @@ enum key_extra
 #define K_MOUSERIGHT	TERMCAP2KEY(KS_EXTRA, KE_MOUSERIGHT)
 
 #define K_CSI		TERMCAP2KEY(KS_EXTRA, KE_CSI)
+#define K_OSC		TERMCAP2KEY(KS_EXTRA, KE_OSC)
 #define K_SNR		TERMCAP2KEY(KS_EXTRA, KE_SNR)
 #define K_PLUG		TERMCAP2KEY(KS_EXTRA, KE_PLUG)
 #define K_CMDWIN	TERMCAP2KEY(KS_EXTRA, KE_CMDWIN)

src/misc2.c

@@ -1053,6 +1053,7 @@ static struct key_name_entry
     {TRUE, NL, STRING_INIT("NewLine"), TRUE},
     {TRUE, NL, STRING_INIT("NL"), FALSE},
     {TRUE, K_ZERO, STRING_INIT("Nul"), FALSE},
+    {TRUE, OSC, STRING_INIT("OSC"), FALSE},
     {TRUE, K_PAGEDOWN, STRING_INIT("PageDown"), FALSE},
     {TRUE, K_PAGEUP, STRING_INIT("PageUp"), FALSE},
     {TRUE, K_PE, STRING_INIT("PasteEnd"), FALSE},
@@ -1111,6 +1112,7 @@ static struct key_name_entry
     {TRUE, K_XF4, STRING_INIT("xF4"), FALSE},
     {TRUE, K_XHOME, STRING_INIT("xHome"), FALSE},
     {TRUE, K_XLEFT, STRING_INIT("xLeft"), FALSE},
+    {TRUE, K_OSC, STRING_INIT("xOSC"), FALSE},
     {TRUE, K_XRIGHT, STRING_INIT("xRight"), FALSE},
     {TRUE, K_XUP, STRING_INIT("xUp"), FALSE},
     {TRUE, K_ZEND, STRING_INIT("zEnd"), FALSE},

src/term.c

@@ -5921,6 +5921,9 @@ handle_osc(char_u *tp, int len, char_u *key_name, int *slen)
 	// The whole OSC response may be larger than the typeahead buffer.
 	// To handle this, keep reading data in and out of the typeahead
 	// buffer until we read an OSC terminator or timeout.
+
+	// We can't use the previous buffer since we transferred ownership of it
+	// to the vim var.
 	ga_init2(&osc_state.buf, 1, 1024);
 #ifdef ELAPSED_FUNC
 	ELAPSED_INIT(osc_state.start_tv);
@@ -5933,7 +5936,6 @@ handle_osc(char_u *tp, int len, char_u *key_name, int *slen)
 	last_char = ((char_u *)osc_state.buf.ga_data)[osc_state.buf.ga_len - 1];
 
     key_name[0] = (int)KS_EXTRA;
-    key_name[1] = (int)KE_IGNORE;
 
     // Read data and append to buffer. If we reach a terminator, then
     // finally set the vim var.
@@ -5945,6 +5947,8 @@ handle_osc(char_u *tp, int len, char_u *key_name, int *slen)
 	{
 	    osc_state.processing = FALSE;
 
+	    key_name[1] = (int)KE_OSC;
+
 	    ga_concat_len(&osc_state.buf, tp, i + 1 + (tp[i] == ESC));
 	    ga_append(&osc_state.buf, NUL);
 	    *slen = i + 1 + (tp[i] == ESC);
@@ -5962,6 +5966,8 @@ handle_osc(char_u *tp, int len, char_u *key_name, int *slen)
 	    return OK;
 	}
 
+    key_name[1] = (int)KE_IGNORE;
+
 #ifdef ELAPSED_FUNC
     if (ELAPSED_FUNC(osc_state.start_tv) >= p_ost)
     {
@@ -6167,9 +6173,15 @@ check_termcode(
 	}
 
 	if (osc_state.processing)
+	{
 	    // Still processing OSC response data, go straight to handler
 	    // function.
+	    tp[len] = NUL;
+	    key_name[0] = NUL;
+	    key_name[1] = NUL;
+	    modifiers = 0;
 	    goto handle_osc;
+	}
 
 	/*
 	 * Skip this position if the character does not appear as the first
@@ -6690,12 +6702,8 @@ check_termcode(
 	 */
 	key = handle_x_keys(TERMCAP2KEY(key_name[0], key_name[1]));
 
-	if (osc_state.processing)
-	    // We don't want to add anything to the typeahead buffer.
-	    new_slen = 0;
-	else
-	    // Add any modifier codes to our string.
-	    new_slen = modifiers2keycode(modifiers, &key, string);
+	// Add any modifier codes to our string.
+	new_slen = modifiers2keycode(modifiers, &key, string);
 
 	// Finally, add the special key code to our string
 	key_name[0] = KEY2TERMCAP0(key);
@@ -6708,8 +6716,10 @@ check_termcode(
 	    else
 		string[new_slen++] = key_name[1];
 	}
-	else if (new_slen == 0 && key_name[0] == KS_EXTRA
-						  && key_name[1] == KE_IGNORE)
+	else if (osc_state.processing ||
+		(new_slen == 0
+		 && key_name[0] == KS_EXTRA
+		 && key_name[1] == KE_IGNORE))
 	{
 	    // Do not put K_IGNORE into the buffer, do return KEYLEN_REMOVED
 	    // to indicate what happened.

src/testdir/test_termcodes.vim

@@ -2847,14 +2847,38 @@ func Test_term_response_osc()
   " Test if large OSC responses (that must be processed in chunks) are handled
   let data = repeat('a', 3000)
 
-  call feedkeys("\<Esc>]12;" .. data .. "\x07", 'Lx!')
-  call assert_equal("\<Esc>]12;" .. data .. "\x07", v:termosc)
+  call feedkeys("\<Esc>]12;" .. data .. "\<Esc>\\", 'Lx!')
+  call assert_equal("\<Esc>]12;" .. data .. "\<Esc>\\", v:termosc)
 
   " Test small OSC responses
-  call feedkeys("\<Esc>]15;hello world!\07", 'Lx!')
+  call feedkeys("\<Esc>]15;hello world!\x07", 'Lx!')
   call assert_equal("\<Esc>]15;hello world!\x07", v:termosc)
 endfunc
 
+" Test if xOSC key is emitted.
+func Test_term_response_xosc_key()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+    func Test()
+      while getcharstr(-1) != "\<xOSC>"
+      endwhile
+      call writefile(["done"], 'XTestResult')
+    endfunc
+  END
+  call writefile(lines, 'XTest', 'D')
+  defer delete('XTestResult')
+
+  let buf = RunVimInTerminal("-S XTest", {'rows': 10})
+  call TermWait(buf)
+  call term_sendkeys(buf, "\<Esc>:call Test()\<CR>")
+  call TermWait(buf)
+  call term_sendkeys(buf, "\<Esc>]52;hello;\<Esc>\\")
+  call TermWait(buf)
+  call WaitForAssert({-> assert_equal(["done"], readfile('XTestResult'))})
+  call StopVimInTerminal(buf)
+endfunc
+
 " This only checks if the sequence is recognized.
 func Test_term_rgb_response()
   set t_RF=x

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1932,
 /**/
     1931,
 /**/