patch 9.0.0321: cannot use the message popup window directly

Problem:    Cannot use the message popup window directly.
Solution:   Add ":echowindow".

runtime/doc/eval.txt

@@ -3821,6 +3821,16 @@ text...
 		:echomsg "It's a Zizzer Zazzer Zuzz, as you can plainly see."
 <			See |:echo-redraw| to avoid the message disappearing
 			when the screen is redrawn.
+
+					*:echow* *:echowin* *:echowindow*
+:echow[indow] {expr1} ..
+			Like |:echomsg| but when the messages popup window is
+			available the message is displayed there.  This means
+			it will show for three seconds and avoid a
+			|hit-enter| prompt.
+			The message window is available when Vim was compiled
+			with the +timer and the +popupwin features.
+
 							*:echoe* *:echoerr*
 :echoe[rr] {expr1} ..	Echo the expression(s) as an error message, saving the
 			message in the |message-history|.  When used in a

src/eval.c

@@ -2078,7 +2078,8 @@ set_context_for_expression(
     if ((cmdidx == CMD_execute
 		|| cmdidx == CMD_echo
 		|| cmdidx == CMD_echon
-		|| cmdidx == CMD_echomsg)
+		|| cmdidx == CMD_echomsg
+		|| cmdidx == CMD_echowindow)
 	    && xp->xp_context == EXPAND_EXPRESSION)
     {
 	for (;;)
@@ -6709,6 +6710,7 @@ get_echo_attr(void)
 /*
  * ":execute expr1 ..."	execute the result of an expression.
  * ":echomsg expr1 ..."	Print a message
+ * ":echowindow expr1 ..." Print a message in the messages window
  * ":echoerr expr1 ..."	Print an error
  * ":echoconsole expr1 ..." Print a message on stdout
  * Each gets spaces around each argument and a newline at the end for
@@ -6726,6 +6728,9 @@ ex_execute(exarg_T *eap)
     long	start_lnum = SOURCING_LNUM;
 
     ga_init2(&ga, 1, 80);
+#ifdef HAS_MESSAGE_WINDOW
+    in_echowindow = (eap->cmdidx == CMD_echowindow);
+#endif
 
     if (eap->skip)
 	++emsg_skip;
@@ -6780,7 +6785,9 @@ ex_execute(exarg_T *eap)
 	// use the first line of continuation lines for messages
 	SOURCING_LNUM = start_lnum;
 
-	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echoerr)
+	if (eap->cmdidx == CMD_echomsg
+		|| eap->cmdidx == CMD_echowindow
+		|| eap->cmdidx == CMD_echoerr)
 	{
 	    // Mark the already saved text as finishing the line, so that what
 	    // follows is displayed on a new line when scrolling back at the
@@ -6788,7 +6795,7 @@ ex_execute(exarg_T *eap)
 	    msg_sb_eol();
 	}
 
-	if (eap->cmdidx == CMD_echomsg)
+	if (eap->cmdidx == CMD_echomsg || eap->cmdidx == CMD_echowindow)
 	{
 	    msg_attr(ga.ga_data, echo_attr);
 	    out_flush();
@@ -6835,6 +6842,7 @@ ex_execute(exarg_T *eap)
 	if (msg_col == 0)
 	    msg_col = 1;
     }
+    in_echowindow = FALSE;
 #endif
     set_nextcmd(eap, arg);
 }

src/ex_cmdidxs.h

@@ -10,27 +10,27 @@ static const unsigned short cmdidxs1[26] =
   /* c */ 45,
   /* d */ 112,
   /* e */ 137,
-  /* f */ 165,
+  /* f */ 166,
-  /* g */ 182,
+  /* g */ 183,
-  /* h */ 188,
+  /* h */ 189,
-  /* i */ 197,
+  /* i */ 198,
-  /* j */ 217,
+  /* j */ 218,
-  /* k */ 219,
+  /* k */ 220,
-  /* l */ 224,
+  /* l */ 225,
-  /* m */ 287,
+  /* m */ 288,
-  /* n */ 305,
+  /* n */ 306,
-  /* o */ 325,
+  /* o */ 326,
-  /* p */ 337,
+  /* p */ 338,
-  /* q */ 376,
+  /* q */ 377,
-  /* r */ 379,
+  /* r */ 380,
-  /* s */ 399,
+  /* s */ 400,
-  /* t */ 469,
+  /* t */ 470,
-  /* u */ 515,
+  /* u */ 516,
-  /* v */ 526,
+  /* v */ 527,
-  /* w */ 547,
+  /* w */ 548,
-  /* x */ 561,
+  /* x */ 562,
-  /* y */ 571,
+  /* y */ 572,
-  /* z */ 572
+  /* z */ 573
 };
 
 /*
@@ -45,7 +45,7 @@ static const unsigned char cmdidxs2[26][26] =
   /* b */ {  2,  0,  0,  5,  6,  8,  0,  0,  0,  0,  0,  9, 10, 11, 12, 13,  0, 14,  0,  0,  0,  0, 23,  0,  0,  0 },
   /* c */ {  3, 12, 16, 18, 20, 22, 25,  0,  0,  0,  0, 33, 38, 41, 47, 57, 59, 60, 61,  0, 63,  0, 66,  0,  0,  0 },
   /* d */ {  0,  0,  0,  0,  0,  0,  0,  0,  8, 18,  0, 19,  0,  0, 20,  0,  0, 22, 23,  0,  0,  0,  0,  0,  0,  0 },
-  /* e */ {  1,  0,  2,  0,  0,  0,  0,  0,  0,  0,  0,  8, 10, 11,  0,  0,  0,  0,  0,  0,  0, 22,  0, 23,  0,  0 },
+  /* e */ {  1,  0,  2,  0,  0,  0,  0,  0,  0,  0,  0,  9, 11, 12,  0,  0,  0,  0,  0,  0,  0, 23,  0, 24,  0,  0 },
   /* f */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 10,  0,  0,  0,  0,  0, 16,  0,  0,  0,  0,  0 },
   /* g */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  0,  0,  2,  0,  0,  4,  5,  0,  0,  0,  0 },
   /* h */ {  5,  0,  0,  0,  0,  0,  0,  0,  6,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 },
@@ -69,4 +69,4 @@ static const unsigned char cmdidxs2[26][26] =
   /* z */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 }
 };
 
-static const int command_count = 589;
+static const int command_count = 590;

src/ex_cmds.h

@@ -548,6 +548,9 @@ EXCMD(CMD_echoconsole,	"echoconsole",	ex_execute,
 EXCMD(CMD_echon,	"echon",	ex_echo,
 	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
+EXCMD(CMD_echowindow,	"echowindow",	ex_execute,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	ADDR_NONE),
 EXCMD(CMD_else,		"else",		ex_else,
 	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),

src/ex_getln.c

@@ -3872,6 +3872,8 @@ redrawcmdprompt(void)
     void
 redrawcmd(void)
 {
+    int save_in_echowindow = in_echowindow;
+
     if (cmd_silent)
 	return;
 
@@ -3883,6 +3885,9 @@ redrawcmd(void)
 	return;
     }
 
+    // Do not put this in the message window.
+    in_echowindow = FALSE;
+
     sb_text_restart_cmdline();
     msg_start();
     redrawcmdprompt();
@@ -3906,6 +3911,8 @@ redrawcmd(void)
     // Typing ':' at the more prompt may set skip_redraw.  We don't want this
     // in cmdline mode
     skip_redraw = FALSE;
+
+    in_echowindow = save_in_echowindow;
 }
 
     void

src/globals.h

@@ -236,6 +236,7 @@ EXTERN int	uncaught_emsg;		    // number of times emsg() was
 EXTERN int	did_emsg_syntax;	    // did_emsg set because of a
 					    // syntax error
 EXTERN int	called_emsg;		    // always incremented by emsg()
+EXTERN int	in_echowindow;		    // executing ":echowindow"
 EXTERN int	ex_exitval INIT(= 0);	    // exit value for ex mode
 EXTERN int	emsg_on_display INIT(= FALSE);	// there is an error message
 EXTERN int	rc_did_emsg INIT(= FALSE);  // vim_regcomp() called emsg()

src/message.c

@@ -1438,7 +1438,8 @@ use_message_window(void)
 #ifdef HAS_MESSAGE_WINDOW
     // TRUE if there is no command line showing ('cmdheight' is zero and not
     // already editing or showing a message) use a popup window for messages.
-    return p_ch == 0 && cmdline_row >= Rows;
+    // Also when using ":echowindow".
+    return (p_ch == 0 && cmdline_row >= Rows) || in_echowindow;
 #else
     return FALSE;
 #endif
@@ -1484,8 +1485,9 @@ msg_start(void)
 #ifdef HAS_MESSAGE_WINDOW
     if (use_message_window())
     {
-	if (popup_message_win_visible() && msg_col > 0
+	if (popup_message_win_visible()
-					       && (msg_scroll || !full_screen))
+		    && ((msg_col > 0 && (msg_scroll || !full_screen))
+			|| in_echowindow))
 	{
 	    win_T *wp = popup_get_message_win();
 

src/popupwin.c

@@ -1302,7 +1302,8 @@ popup_adjust_position(win_T *wp)
 	}
 	if (wp->w_popup_pos == POPPOS_BOTTOM)
 	    // assume that each buffer line takes one screen line
-	    wp->w_winrow = MAX(Rows - wp->w_buffer->b_ml.ml_line_count - 1, 0);
+	    wp->w_winrow = MAX(cmdline_row
+				    - wp->w_buffer->b_ml.ml_line_count - 1, 0);
 
 	if (!use_wantcol)
 	    center_hor = TRUE;

src/structs.h

@@ -2606,7 +2606,7 @@ typedef enum {
     POPPOS_BOTRIGHT,
     POPPOS_TOPRIGHT,
     POPPOS_CENTER,
-    POPPOS_BOTTOM,	// bottom of popup at bottom of screen
+    POPPOS_BOTTOM,	// bottom of popup just above the command line
     POPPOS_NONE
 } poppos_T;
 

src/testdir/dumps/Test_echowindow_1.dump

@@ -0,0 +1,8 @@
+>s+0&#ffffff0|o|m|e| |t|e|x|t| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|═+0#e000002&@74
+|f|i|r|s|t| |l|i|n|e| @64
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/dumps/Test_echowindow_2.dump

@@ -0,0 +1,8 @@
+>s+0&#ffffff0|o|m|e| |t|e|x|t| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|═+0#e000002&@74
+|f|i|r|s|t| |l|i|n|e| @64
+|s|e|c|o|n|d| |l|i|n|e| @63
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/dumps/Test_echowindow_3.dump

@@ -0,0 +1,8 @@
+>s+0&#ffffff0|o|m|e| |t|e|x|t| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/test_messages.vim

@@ -537,5 +537,30 @@ func Test_cmdheight_zero_shell()
   set cmdheight&
 endfunc
 
+func Test_echowindow()
+  CheckScreendump
+
+  let lines =<< trim END
+      call setline(1, 'some text')
+      func ShowMessage(arg)
+        echowindow a:arg
+      endfunc
+      echowindow 'first line'
+  END
+  call writefile(lines, 'XtestEchowindow')
+  let buf = RunVimInTerminal('-S XtestEchowindow', #{rows: 8})
+  call VerifyScreenDump(buf, 'Test_echowindow_1', {})
+
+  call term_sendkeys(buf, ":call ShowMessage('second line')\<CR>")
+  call VerifyScreenDump(buf, 'Test_echowindow_2', {})
+
+  call term_sendkeys(buf, ":call popup_clear()\<CR>")
+  call VerifyScreenDump(buf, 'Test_echowindow_3', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('XtestEchowindow')
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -707,6 +707,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    321,
 /**/
     320,
 /**/