patch 9.1.0574: ex: wrong handling of commands after bar

Problem:  ex: wrong handling of commands after bar
Solution: for :append, :insert and :change use the text after the bar
          as input for those commands. This is what POSIX requests.
          (Mohamed Akram)

See the POSIX Spec:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/ex.html#tag_20_40_13_03
Section 12.c

closes: #15229

Signed-off-by: Mohamed Akram <mohd.akram@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/insert.txt

@@ -1,4 +1,4 @@
-*insert.txt*    For Vim version 9.1.  Last change: 2024 Jul 12
+*insert.txt*    For Vim version 9.1.  Last change: 2024 Jul 13
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1995,6 +1995,16 @@ These two commands will keep on asking for lines, until you type a line
 containing only a ".".  Watch out for lines starting with a backslash, see
 |line-continuation|.
 
+Text typed after a "|" command separator is used first. So the following
+command in ex mode: >
+	:a|one
+	two
+	.
+	:visual
+<appends the following text, after the cursor line: >
+	one
+	two
+<
 NOTE: These commands cannot be used with |:global| or |:vglobal|.
 ":append" and ":insert" don't work properly in between ":if" and
 ":endif", ":for" and ":endfor", ":while" and ":endwhile".

src/ex_cmds.c

@@ -3360,7 +3360,13 @@ ex_append(exarg_T *eap)
 		indent = get_indent_lnum(lnum);
 	}
 	ex_keep_indent = FALSE;
-	if (eap->ea_getline == NULL)
+	if (*eap->arg == '|')
+	{
+	    // Get the text after the trailing bar.
+	    theline = vim_strsave(eap->arg + 1);
+	    *eap->arg = NUL;
+	}
+	else if (eap->ea_getline == NULL)
 	{
 	    // No getline() function, use the lines that follow. This ends
 	    // when there is no more.

src/ex_docmd.c

@@ -5401,7 +5401,11 @@ separate_nextcmd(exarg_T *eap, int keep_backslash)
 		    && in_vim9script()
 		    && !(eap->argt & EX_NOTRLCOM)
 		    && p > eap->cmd && VIM_ISWHITE(p[-1]))
-		|| *p == '|' || *p == '\n')
+		|| (*p == '|'
+		    && eap->cmdidx != CMD_append
+		    && eap->cmdidx != CMD_change
+		    && eap->cmdidx != CMD_insert)
+		|| *p == '\n')
 	{
 	    /*
 	     * We remove the '\' before the '|', unless EX_CTRLV is used

src/testdir/test_ex_mode.vim

@@ -364,4 +364,12 @@ func Test_implicit_print()
   call setline(1, ['one', 'two', 'three'])
   call feedkeys('Q:let a=execute(":1,2")', 'xt')
   call feedkeys('Q:let b=execute(":3")', 'xt')
+  call assert_equal('one two', a->split('\n')->join(' '))
+  call assert_equal('three', b->split('\n')->join(' '))
+  bw!
+endfunc
+
+" Test inserting text after the trailing bar
+func Test_insert_after_trailing_bar()
+  new
   call feedkeys("Qi|\nfoo\n.\na|bar\nbar\n.\nc|baz\n.", "xt")

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    574,
 /**/
     573,
 /**/