patch 8.1.0253: saving and restoring window title does not always work

Problem:    Saving and restoring window title does not always work.
Solution:   Use the stack push and pop commands. (Kouichi Iwamoto,
            closes #3059)

runtime/doc/term.txt

@@ -352,6 +352,10 @@ Added by Vim (there are no standard codes for these):
 	t_SH	set cursor shape				*t_SH* *'t_SH'*
 	t_RC	request terminal cursor blinking		*t_RC* *'t_RC'*
 	t_RS	request terminal cursor style			*t_RS* *'t_RS'*
+	t_ST	save window title to stack			*t_ST* *'t_ST'*
+	t_RT	restore window title from stack			*t_RT* *'t_RT'*
+	t_Si	save icon text to stack				*t_Si* *'t_Si'*
+	t_Ri	restore icon text from stack			*t_Ri* *'t_Ri'*
 
 Some codes have a start, middle and end part.  The start and end are defined
 by the termcap option, the middle part is text.

src/buffer.c

@@ -3798,7 +3798,8 @@ value_changed(char_u *str, char_u **last)
 	if (str == NULL)
 	{
 	    *last = NULL;
-	    mch_restore_title(last == &lasttitle ? 1 : 2);
+	    mch_restore_title(
+		  last == &lasttitle ? SAVE_RESTORE_TITLE : SAVE_RESTORE_ICON);
 	}
 	else
 	{

src/ex_docmd.c

@@ -7750,7 +7750,7 @@ ex_stop(exarg_T *eap)
 	stoptermcap();
 	out_flush();		/* needed for SUN to restore xterm buffer */
 #ifdef FEAT_TITLE
-	mch_restore_title(3);	/* restore window titles */
+	mch_restore_title(SAVE_RESTORE_BOTH);	/* restore window titles */
 #endif
 	ui_suspend();		/* call machine specific function */
 #ifdef FEAT_TITLE

src/main.c

@@ -706,6 +706,10 @@ vim_main2(void)
 	scroll_region_reset();		/* In case Rows changed */
     scroll_start();	/* may scroll the screen to the right position */
 
+#ifdef FEAT_TITLE
+    term_push_title(SAVE_RESTORE_BOTH);
+#endif
+
     /*
      * Don't clear the screen when starting in Ex mode, unless using the GUI.
      */

src/option.c

@@ -3192,7 +3192,9 @@ static struct vimoption options[] =
     p_term("t_RB", T_RBG)
     p_term("t_RC", T_CRC)
     p_term("t_RI", T_CRI)
+    p_term("t_Ri", T_SRI)
     p_term("t_RS", T_CRS)
+    p_term("t_RT", T_CRT)
     p_term("t_RV", T_CRV)
     p_term("t_Sb", T_CSB)
     p_term("t_SC", T_CSC)
@@ -3200,9 +3202,11 @@ static struct vimoption options[] =
     p_term("t_Sf", T_CSF)
     p_term("t_SH", T_CSH)
     p_term("t_SI", T_CSI)
+    p_term("t_Si", T_SSI)
     p_term("t_so", T_SO)
     p_term("t_SR", T_CSR)
     p_term("t_sr", T_SR)
+    p_term("t_ST", T_CST)
     p_term("t_Te", T_STE)
     p_term("t_te", T_TE)
     p_term("t_ti", T_TI)
@@ -10414,7 +10418,7 @@ clear_termoptions(void)
     mch_setmouse(FALSE);	    /* switch mouse off */
 #endif
 #ifdef FEAT_TITLE
-    mch_restore_title(3);	    /* restore window titles */
+    mch_restore_title(SAVE_RESTORE_BOTH);    /* restore window titles */
 #endif
 #if defined(FEAT_XCLIPBOARD) && defined(FEAT_GUI)
     /* When starting the GUI close the display opened for the clipboard.
@@ -11219,8 +11223,8 @@ buf_copy_options(buf_T *buf, int flags)
 		buf->b_p_isk = NULL;
 	    }
 	    /*
-	     * Always free the allocated strings.
+	     * Always free the allocated strings.  If not already initialized,
-	     * If not already initialized, set 'readonly' and copy 'fileformat'.
+	     * reset 'readonly' and copy 'fileformat'.
 	     */
 	    if (!buf->b_p_initialized)
 	    {

src/os_amiga.c

@@ -617,14 +617,14 @@ mch_settitle(char_u *title, char_u *icon)
 /*
  * Restore the window/icon title.
  * which is one of:
- *  1  Just restore title
+ *  SAVE_RESTORE_TITLE  Just restore title
- *  2  Just restore icon (which we don't have)
+ *  SAVE_RESTORE_ICON   Just restore icon (which we don't have)
- *  3  Restore title and icon (which we don't have)
+ *  SAVE_RESTORE_BOTH   Restore title and icon (which we don't have)
  */
     void
 mch_restore_title(int which)
 {
-    if (which & 1)
+    if (which & SAVE_RESTORE_TITLE)
 	mch_settitle(oldwindowtitle, NULL);
 }
 
@@ -907,7 +907,7 @@ mch_exit(int r)
     }
 
 #ifdef FEAT_TITLE
-    mch_restore_title(3);	    /* restore window title */
+    mch_restore_title(SAVE_RESTORE_BOTH);    /* restore window title */
 #endif
 
     ml_close_all(TRUE);		    /* remove all memfiles */

src/os_mswin.c

@@ -304,9 +304,9 @@ mch_settitle(
 /*
  * Restore the window/icon title.
  * which is one of:
- *  1: Just restore title
+ *  SAVE_RESTORE_TITLE: Just restore title
- *  2: Just restore icon (which we don't have)
+ *  SAVE_RESTORE_ICON:  Just restore icon (which we don't have)
- *  3: Restore title and icon (which we don't have)
+ *  SAVE_RESTORE_BOTH:  Restore title and icon (which we don't have)
  */
     void
 mch_restore_title(int which UNUSED)

src/os_unix.c

@@ -2336,17 +2336,21 @@ mch_settitle(char_u *title, char_u *icon)
 /*
  * Restore the window/icon title.
  * "which" is one of:
- *  1  only restore title
+ *  SAVE_RESTORE_TITLE only restore title
- *  2  only restore icon
+ *  SAVE_RESTORE_ICON  only restore icon
- *  3  restore title and icon
+ *  SAVE_RESTORE_BOTH  restore title and icon
  */
     void
 mch_restore_title(int which)
 {
     /* only restore the title or icon when it has been set */
-    mch_settitle(((which & 1) && did_set_title) ?
+    mch_settitle(((which & SAVE_RESTORE_TITLE) && did_set_title) ?
 			(oldtitle ? oldtitle : p_titleold) : NULL,
-			      ((which & 2) && did_set_icon) ? oldicon : NULL);
+	       ((which & SAVE_RESTORE_ICON) && did_set_icon) ? oldicon : NULL);
+
+    // pop and push from/to the stack
+    term_pop_title(which);
+    term_push_title(which);
 }
 
 #endif /* FEAT_TITLE */
@@ -3412,7 +3416,9 @@ mch_exit(int r)
     {
 	settmode(TMODE_COOK);
 #ifdef FEAT_TITLE
-	mch_restore_title(3);	/* restore xterm title and icon name */
+	// restore xterm title and icon name
+	mch_restore_title(SAVE_RESTORE_BOTH);
+	term_pop_title(SAVE_RESTORE_BOTH);
 #endif
 	/*
 	 * When t_ti is not empty but it doesn't cause swapping terminal

src/os_win32.c

@@ -2695,7 +2695,7 @@ mch_exit(int r)
     if (g_fWindInitCalled)
     {
 #ifdef FEAT_TITLE
-	mch_restore_title(3);
+	mch_restore_title(SAVE_RESTORE_BOTH);
 	/*
 	 * Restore both the small and big icons of the console window to
 	 * what they were at startup.  Don't do this when the window is

src/proto/term.pro

@@ -31,6 +31,8 @@ void term_bg_color(int n);
 void term_fg_rgb_color(guicolor_T rgb);
 void term_bg_rgb_color(guicolor_T rgb);
 void term_settitle(char_u *title);
+void term_push_title(int which);
+void term_pop_title(int which);
 void ttest(int pairs);
 void add_long_to_buf(long_u val, char_u *dst);
 void check_shellsize(void);

src/term.c

@@ -922,6 +922,10 @@ static struct builtin_term builtin_termcaps[] =
 #  endif
     {(int)KS_CBE,	IF_EB("\033[?2004h", ESC_STR "[?2004h")},
     {(int)KS_CBD,	IF_EB("\033[?2004l", ESC_STR "[?2004l")},
+    {(int)KS_CST,	IF_EB("\033[22;2t", ESC_STR "[22;2t")},
+    {(int)KS_CRT,	IF_EB("\033[23;2t", ESC_STR "[23;2t")},
+    {(int)KS_SSI,	IF_EB("\033[22;1t", ESC_STR "[22;1t")},
+    {(int)KS_SRI,	IF_EB("\033[23;1t", ESC_STR "[23;1t")},
 
     {K_UP,		IF_EB("\033O*A", ESC_STR "O*A")},
     {K_DOWN,		IF_EB("\033O*B", ESC_STR "O*B")},
@@ -1600,6 +1604,8 @@ get_term_entries(int *height, int *width)
 			{KS_8F, "8f"}, {KS_8B, "8b"},
 			{KS_CBE, "BE"}, {KS_CBD, "BD"},
 			{KS_CPS, "PS"}, {KS_CPE, "PE"},
+			{KS_CST, "ST"}, {KS_CRT, "RT"},
+			{KS_SSI, "Si"}, {KS_SRI, "Ri"},
 			{(enum SpecialKey)0, NULL}
 		    };
     int		    i;
@@ -2974,6 +2980,45 @@ term_settitle(char_u *title)
     out_str(T_FS);			/* set title end */
     out_flush();
 }
+
+/*
+ * Tell the terminal to push (save) the title and/or icon, so that it can be
+ * popped (restored) later.
+ */
+    void
+term_push_title(int which)
+{
+    if ((which & SAVE_RESTORE_TITLE) && *T_CST != NUL)
+    {
+	OUT_STR(T_CST);
+	out_flush();
+    }
+
+    if ((which & SAVE_RESTORE_ICON) && *T_SSI != NUL)
+    {
+	OUT_STR(T_SSI);
+	out_flush();
+    }
+}
+
+/*
+ * Tell the terminal to pop the title and/or icon.
+ */
+    void
+term_pop_title(int which)
+{
+    if ((which & SAVE_RESTORE_TITLE) && *T_CRT != NUL)
+    {
+	OUT_STR(T_CRT);
+	out_flush();
+    }
+
+    if ((which & SAVE_RESTORE_ICON) && *T_SRI != NUL)
+    {
+	OUT_STR(T_SRI);
+	out_flush();
+    }
+}
 #endif
 
 /*

src/term.h

@@ -101,10 +101,14 @@ enum SpecialKey
     KS_CBE,	/* enable bracketed paste mode */
     KS_CBD,	/* disable bracketed paste mode */
     KS_CPS,	/* start of bracketed paste */
-    KS_CPE	/* end of bracketed paste */
+    KS_CPE,	/* end of bracketed paste */
+    KS_CST,	/* save window title */
+    KS_CRT,	/* restore window title */
+    KS_SSI,	/* save icon text */
+    KS_SRI	/* restore icon text */
 };
 
-#define KS_LAST	    KS_CPE
+#define KS_LAST	    KS_SRI
 
 /*
  * the terminal capabilities are stored in this array
@@ -196,6 +200,10 @@ extern char_u *(term_strings[]);    /* current terminal strings */
 #define T_BD	(TERM_STR(KS_CBD))	/* disable bracketed paste mode */
 #define T_PS	(TERM_STR(KS_CPS))	/* start of bracketed paste */
 #define T_PE	(TERM_STR(KS_CPE))	/* end of bracketed paste */
+#define T_CST	(TERM_STR(KS_CST))	/* save window title */
+#define T_CRT	(TERM_STR(KS_CRT))	/* restore window title */
+#define T_SSI	(TERM_STR(KS_SSI))	/* save icon text */
+#define T_SRI	(TERM_STR(KS_SRI))	/* restore icon text */
 
 #define TMODE_COOK  0	/* terminal mode for external cmds and Ex mode */
 #define TMODE_SLEEP 1	/* terminal mode for sleeping (cooked but no echo) */

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    253,
 /**/
     252,
 /**/

src/vim.h

@@ -2548,4 +2548,16 @@ typedef enum {
 #define TERM_START_FORCEIT	2
 #define TERM_START_SYSTEM	4
 
+#if defined(HAVE_DROP_FILE) \
+	|| (defined(FEAT_GUI_GTK) && defined(FEAT_DND)) \
+	|| defined(FEAT_GUI_MSWIN) \
+	|| defined(FEAT_GUI_MAC)
+# define HAVE_HANDLE_DROP
+#endif
+
+// Used for icon/title save and restore.
+#define SAVE_RESTORE_TITLE	1
+#define SAVE_RESTORE_ICON	2
+#define SAVE_RESTORE_BOTH	(SAVE_RESTORE_TITLE | SAVE_RESTORE_ICON)
+
 #endif /* VIM__H */