patch 8.2.3079: Powershell core not supported by default

Problem:    Powershell core not supported by default.
Solution:   Set option defaults for "pwsh". (Mike Williams, closes #8481)
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 7fb2534..2eceece 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -9878,11 +9878,13 @@
 
 shellescape({string} [, {special}])			*shellescape()*
 		Escape {string} for use as a shell command argument.
-		On MS-Windows, when the 'shell' contains powershell then it
-		will enclose {string} in single quotes and will double up all
-		internal single quotes.  With other values for 'shell' when
-		'shellslash' is not set, it will enclose {string} in double
-		quotes and double all double quotes within {string}.
+		When the 'shell' contains powershell (MS-Windows) or pwsh
+		(MS-Windows, Linux, and MacOS) then it will enclose {string}
+		in single quotes and will double up all internal single
+		quotes.
+		On MS-Windows, when 'shellslash' is not set, it will enclose
+		{string} in double quotes and double all double quotes within
+		{string}.
 		Otherwise it will enclose {string} in single quotes and
 		replace all "'" with "'\''".
 
@@ -11042,8 +11044,8 @@
 			:exe "redir > " . tmpfile
 <		For Unix, the file will be in a private directory |tempfile|.
 		For MS-Windows forward slashes are used when the 'shellslash'
-		option is set or when 'shellcmdflag' starts with '-' except
-		when when 'shell' contains powershell.
+		option is set, or when 'shellcmdflag' starts with '-' and
+		'shell' does not contain powershell or pwsh.
 
 
 term_ functions are documented here: |terminal-function-details|
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index b958cf6..af2e23e 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -6633,6 +6633,8 @@
 	"bash", "fish", "ash" or "dash" the default becomes "2>&1| tee".  This
 	means that stderr is also included.  Before using the 'shell' option a
 	path is removed, thus "/bin/sh" uses "sh".
+	For Unix and MS-Windows, when the 'shell' option is "pwsh" the default
+	becomes ">%s 2>&1" and the output is not echoed to the screen.
 	The initialization of this option is done after reading the ".vimrc"
 	and the other initializations, so that when the 'shell' option is set
 	there, the 'shellpipe' option changes automatically, unless it was
@@ -6648,9 +6650,7 @@
 	security reasons.
 
 						*'shellquote'* *'shq'*
-'shellquote' 'shq'	string	(default: ""; Win32, when 'shell' does not
-				 contain powershell but contains "sh"
-				 somewhere: "\"")
+'shellquote' 'shq'	string	(default: "")
 			global
 	Quoting character(s), put around the command passed to the shell, for
 	the "!" and ":!" commands.  The redirection is kept outside of the
@@ -6658,9 +6658,7 @@
 	probably not useful to set both options.
 	This is an empty string by default.  Only known to be useful for
 	third-party shells on MS-Windows-like systems, such as the MKS Korn
-	Shell or bash, where it should be "\"".  The default is adjusted
-	according the value of 'shell', to reduce the need to set this option
-	by the user.  See |dos-shell|.
+	Shell or bash, where it should be "\"".  See |dos-shell|.
 	This option cannot be set from a |modeline| or in the |sandbox|, for
 	security reasons.
 
@@ -6677,12 +6675,12 @@
 	The default is ">".  For Unix, if the 'shell' option is "csh" or
 	"tcsh" during initializations, the default becomes ">&".  If the
 	'shell' option is "sh", "ksh", "mksh", "pdksh", "zsh", "zsh-beta",
-	"bash" or "fish", the default becomes ">%s 2>&1".  This means that
-	stderr is also included.  For Win32, the Unix checks are done and
+	"bash", "fish", or "pwsh", the default becomes ">%s 2>&1".  This means
+	that stderr is also included.  For Win32, the Unix checks are done and
 	additionally "cmd" is checked for, which makes the default ">%s 2>&1",
 	and "powershell" is checked for which makes the default
-	"2>&1 | Out-File -Encoding default".  Also, the same names with ".exe"
-	appended are checked for.
+	"2>&1 | Out-File -Encoding default" (see |dos-powershell|).  Also, the
+	same names with ".exe" appended are checked for.
 	The initialization of this option is done after reading the ".vimrc"
 	and the other initializations, so that when the 'shell' option is set
 	there, the 'shellredir' option changes automatically unless it was
@@ -6697,7 +6695,7 @@
 			global
 			{only for MS-Windows}
 	When set, a forward slash is used when expanding file names.  This is
-	useful when a Unix-like shell is used instead of cmd.exe or
+	useful when a Unix-like shell is used instead of cmd.exe, pwsh.exe, or
 	powershell.exe.  Backward slashes can still be typed, but they are
 	changed to forward slashes by Vim.
 	Note that setting or resetting this option has no effect for some
@@ -6767,10 +6765,10 @@
 	then ')"' is appended.
 	When the value is '(' then also see 'shellxescape'.
 	This is an empty string by default on most systems, but is known to be
-	useful for on Win32 version, either for cmd.exe and powershell.exe
-	which automatically strips off the first and last quote on a command,
-	or 3rd-party shells such as the MKS Korn Shell or bash, where it
-	should be "\"".  The default is adjusted according the value of
+	useful for on Win32 version, either for cmd.exe, powershell.exe, or
+	pwsh.exe which automatically strips off the first and last quote on a
+	command, or 3rd-party shells such as the MKS Korn Shell or bash, where
+	it should be "\"".  The default is adjusted according the value of
 	'shell', to reduce the need to set this option by the user.  See
 	|dos-shell|.
 	This option cannot be set from a |modeline| or in the |sandbox|, for
diff --git a/runtime/doc/os_dos.txt b/runtime/doc/os_dos.txt
index b45cb08..b473134 100644
--- a/runtime/doc/os_dos.txt
+++ b/runtime/doc/os_dos.txt
@@ -304,40 +304,80 @@
 set as described above.
 
 ==============================================================================
-10. PowerShell						*dos-powershell*
+10. PowerShell					*dos-powershell* *dos-pwsh*
 
-Vim also supports Windows PowerShell.  If 'shell' has been set to
-"powershell.exe" at startup then VIM sets 'shellcmdflag', 'shellxquote',
-'shellpipe', and 'shellredir' options to the following values:
+Vim supports PowerShell Desktop and PowerShell Core.  PowerShell Desktop is
+the version of PowerShell that is installed with Windows, while PowerShell
+Core is a separate downloadable version that works cross-platform.  To see
+which version you are using then enter the following in a PowerShell prompt -
+$PSVersionTable.PSEdition
+
+If 'shell' includes "powershell" in the filename at startup then VIM sets
+'shellcmdflag', 'shellxquote', 'shellpipe', and 'shellredir' options to the
+following values:
 
 'shellcmdflag'	-Command
 'shellxquote'	"
 'shellpipe'	2>&1 | Out-File -Encoding default
 'shellredir'	2>&1 | Out-File -Encoding default
 
+If 'shell' includes "pwsh" in the filename at startup then VIM sets
+'shellcmdflag', 'shellxquote', 'shellpipe', and 'shellredir' options to the
+following values:
+
+'shellcmdflag'	-c
+'shellxquote'	"
+'shellpipe'	>%s 2>&1
+'shellredir'	>%s 2>&1
+
 If you find that PowerShell commands are taking a long time to run then try
-setting 'shellcmdflag' to "-NoProfile -Command".  Note this will prevent any
-PowerShell environment setup by the profile from taking place.
+with "-NoProfile" at the beginning of the 'shellcmdflag'.  Note this will
+prevent any PowerShell environment setup by the profile from taking place.
 
 If you have problems running PowerShell scripts through the 'shell' then try
-setting 'shellcmdflag' to "-ExecutionPolicy RemoteSigned -Command".  See
-online Windows documentation for more information on PowerShell Execution
-Policy settings.
+with "-ExecutionPolicy RemoteSigned -Command" at the beginning of
+'shellcmdflag'.  See online Windows documentation for more information on
+PowerShell Execution Policy settings.
+
+See |option-backslash| about including spaces in 'shellcmdflag' when using
+multiple flags.
 
 The 'shellpipe' and 'shellredir' option values re-encode the UTF-16le output
-from Windows PowerShell to your currently configured console codepage.  The
+from PowerShell Desktop to your currently configured console codepage.  The
 output can be forced into a different encoding by changing "default" to one of
 the following:
 
 	unicode		 - UTF-16le (default output from PowerShell 5.1)
 	bigendianunicode - UTF-16
 	utf8		 - UTF-8
-	utf7		 - UTF-7 (no-BOM)
+	utf7		 - UTF-7 (no BOM)
 	utf32		 - UTF-32
 	ascii		 - 7-bit ASCII character set
 	default		 - System's active code page (typically ANSI)
 	oem		 - System's current OEM code page
 
-Note Multi-byte Unicode encodings include a leading BOM.
+Note The abovce multi-byte Unicode encodings include a leading BOM unless
+otherwise indicated.
+
+By default PowerShell Core's output is UTF-8 encoded without a BOM.  If you
+want to force the output of PowerShell Core into a different encoding then set
+'shellredir' and 'shellpipe' to "2>&1 | Out-File -Encoding encoding" where
+encoding is one of the following:
+
+	ascii		 - 7-bit ASCII character set
+	bigendianunicode - UTF-16be
+	bigendianutf32	 - UTF-32be
+	oem		 - System's current OEM code page
+	unicode		 - UTF-16le
+	utf7		 - UTF-7
+	utf8		 - UTF-8
+	utf8BOM		 - UTF-8, with BOM
+	utf8NoBOM	 - UTF-8, no BOM (default output from PowerShell Core)
+	utf32		 - UTF-32
+
+Since PowerShell Core 6.2, the Encoding parameter also supports specifying a
+numeric ID of a registered code page (-Encoding 1251) or string names of
+registered code pages (-Encoding "windows-1251").  The .NET documentation for
+Encoding.CodePage has more information
 
  vim:tw=78:ts=8:noet:ft=help:norl:
diff --git a/runtime/doc/os_win32.txt b/runtime/doc/os_win32.txt
index 6c36608..3767cb8 100644
--- a/runtime/doc/os_win32.txt
+++ b/runtime/doc/os_win32.txt
@@ -30,6 +30,7 @@
 Interrupting			|dos-CTRL-Break|
 Temp files			|dos-temp-files|
 Shell option default		|dos-shell|
+PowerShell defaults		|dos-powershell|
 
 Win32 GUI			|gui-w32|
 
diff --git a/src/fileio.c b/src/fileio.c
index 55012bf..bd4038c 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5222,6 +5222,7 @@
     WCHAR	*chartab = L"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
     char_u	*retval;
     char_u	*p;
+    char_u	*shname;
     long	i;
 
     wcscpy(itmp, L"");
@@ -5247,8 +5248,10 @@
     // "sh".  NOTE: This also checks 'shellcmdflag' to help those people who
     // didn't set 'shellslash' but only if not using PowerShell.
     retval = utf16_to_enc(itmp, NULL);
-    if ((strstr((char *)gettail(p_sh), "powershell") == NULL
-						&& *p_shcf == '-') || p_ssl)
+    shname = gettail(p_sh);
+    if ((*p_shcf == '-' && !(strstr((char *)shname, "powershell") != NULL
+			     || strstr((char *)shname, "pwsh") != NULL ))
+								    || p_ssl)
 	for (p = retval; *p; ++p)
 	    if (*p == '\\')
 		*p = '/';
diff --git a/src/misc2.c b/src/misc2.c
index 6bbfbd7..ead1e63 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -1414,8 +1414,9 @@
     char_u	*escaped_string;
     int		l;
     int		csh_like;
-# ifdef MSWIN
+    char_u	*shname;
     int		powershell;
+# ifdef MSWIN
     int		double_quotes;
 # endif
 
@@ -1425,9 +1426,12 @@
     // Csh also needs to have "\n" escaped twice when do_special is set.
     csh_like = csh_like_shell();
 
+    // PowerShell uses it's own version for quoting single quotes
+    shname = gettail(p_sh);
+    powershell = strstr((char *)shname, "pwsh") != NULL;
 # ifdef MSWIN
-    // PowerShell only accepts single quotes so override p_ssl.
-    powershell = strstr((char *)gettail(p_sh), "powershell") != NULL;
+    powershell = powershell || strstr((char *)shname, "powershell") != NULL;
+    // PowerShell only accepts single quotes so override shellslash.
     double_quotes = !powershell && !p_ssl;
 # endif
 
@@ -1445,11 +1449,9 @@
 # endif
 	if (*p == '\'')
 	{
-# ifdef MSWIN
 	    if (powershell)
 		length +=2;		// ' => ''
 	    else
-# endif
 		length += 3;		// ' => '\''
 	}
 	if ((*p == '\n' && (csh_like || do_newline))
@@ -1497,14 +1499,12 @@
 # endif
 	    if (*p == '\'')
 	    {
-# ifdef MSWIN
 		if (powershell)
 		{
 		    *d++ = '\'';
 		    *d++ = '\'';
 		}
 		else
-# endif
 		{
 		    *d++ = '\'';
 		    *d++ = '\\';
diff --git a/src/option.c b/src/option.c
index 5fc059e..ae30310 100644
--- a/src/option.c
+++ b/src/option.c
@@ -933,8 +933,8 @@
 	    }
 	}
 # ifdef MSWIN
-	// PowerShell 5.1/.NET outputs UTF-16 with BOM so re-encode to the
-	// current codepage
+	// Windows PowerShell output is UTF-16 with BOM so re-encode to the
+	// current codepage.
 	else if (   fnamecmp(p, "powershell") == 0
 		    || fnamecmp(p, "powershell.exe") == 0
 		)
@@ -965,6 +965,7 @@
 		    || fnamecmp(p, "fish") == 0
 		    || fnamecmp(p, "ash") == 0
 		    || fnamecmp(p, "dash") == 0
+		    || fnamecmp(p, "pwsh") == 0
 # ifdef MSWIN
 		    || fnamecmp(p, "cmd") == 0
 		    || fnamecmp(p, "sh.exe") == 0
@@ -976,6 +977,7 @@
 		    || fnamecmp(p, "bash.exe") == 0
 		    || fnamecmp(p, "cmd.exe") == 0
 		    || fnamecmp(p, "dash.exe") == 0
+		    || fnamecmp(p, "pwsh.exe") == 0
 # endif
 		    )
 	    {
@@ -985,7 +987,10 @@
 #  ifdef MSWIN
 		    p_sp = (char_u *)">%s 2>&1";
 #  else
-		    p_sp = (char_u *)"2>&1| tee";
+		    if (fnamecmp(p, "pwsh") == 0)
+			p_sp = (char_u *)">%s 2>&1";
+		    else
+			p_sp = (char_u *)"2>&1| tee";
 #  endif
 		    options[idx_sp].def_val[VI_DEFAULT] = p_sp;
 		}
@@ -1011,6 +1016,7 @@
      *			    p_shcf	p_sxq
      * cmd.exe          -   "/c"	"("
      * powershell.exe   -   "-Command"	"\""
+     * pwsh.exe		-   "-c"	"\""
      * "sh" like shells -   "-c"	"\""
      *
      * For Win32 p_sxq is set instead of p_shq to include shell redirection.
diff --git a/src/os_win32.c b/src/os_win32.c
index 1a005c9..eff2269 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -2135,6 +2135,7 @@
     char_u	*pathbuf = NULL;
     char_u	*pathext = NULL;
     char_u	*pathextbuf = NULL;
+    char_u	*shname = NULL;
     int		noext = FALSE;
     int		retval = FALSE;
 
@@ -2142,8 +2143,10 @@
 	return FALSE;
 
     // Using the name directly when a Unix-shell like 'shell'.
-    if (strstr((char *)gettail(p_sh), "powershell") == NULL
-				&& strstr((char *)gettail(p_sh), "sh") != NULL)
+    shname = gettail(p_sh);
+    if (strstr((char *)shname, "sh") != NULL &&
+	!(strstr((char *)shname, "powershell") != NULL
+				    || strstr((char *)shname, "pwsh") != NULL))
 	noext = TRUE;
 
     if (use_pathext)
diff --git a/src/testdir/test_shell.vim b/src/testdir/test_shell.vim
index 753a0d5..f5a3e98 100644
--- a/src/testdir/test_shell.vim
+++ b/src/testdir/test_shell.vim
@@ -19,7 +19,8 @@
           \ ['ash', '-c', '2>&1| tee', '', '>%s 2>&1', '', ''],
           \ ['dash', '-c', '2>&1| tee', '', '>%s 2>&1', '', ''],
           \ ['csh', '-c', '|& tee', '', '>&', '', ''],
-          \ ['tcsh', '-c', '|& tee', '', '>&', '', '']]
+          \ ['tcsh', '-c', '|& tee', '', '>&', '', ''],
+          \ ['pwsh', '-c', '>%s 2>&1', '', '>%s 2>&1', '', '']]
   endif
   if has('win32')
     let shells += [['cmd', '/c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', ''],
@@ -28,6 +29,8 @@
           \           '', '2>&1 | Out-File -Encoding default', '"&|<>()@^', '"'],
           \ ['powershell', '-Command', '2>&1 | Out-File -Encoding default', '',
           \               '2>&1 | Out-File -Encoding default', '"&|<>()@^', '"'],
+          \ ['pwsh.exe', '-c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '"'],
+          \ ['pwsh', '-c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '"'],
           \ ['sh.exe', '-c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '"'],
           \ ['ksh.exe', '-c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '"'],
           \ ['mksh.exe', '-c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '"'],
@@ -61,6 +64,7 @@
       let str1 = "'cmd \"arg1\" '\\''arg2'\\'' \\!%#'"
       let str2 = "'cmd \"arg1\" '\\''arg2'\\'' \\\\!\\%\\#'"
     elseif e[0] =~# '.*powershell$' || e[0] =~# '.*powershell.exe$'
+          \ || e[0] =~# '.*pwsh$' || e[0] =~# '.*pwsh.exe$'
       let str1 = "'cmd \"arg1\" ''arg2'' !%#'"
       let str2 = "'cmd \"arg1\" ''arg2'' \\!\\%\\#'"
     else
@@ -76,9 +80,14 @@
       let [&shellcmdflag, &shellpipe, &shellquote, &shellredir,
             \ &shellxescape, &shellxquote] = e[1:6]
       new
-      r !echo hello
-      call assert_equal('hello', substitute(getline(2), '\W', '', 'g'), e[0])
-      bwipe!
+      try
+        r !echo hello
+        call assert_equal('hello', substitute(getline(2), '\W', '', 'g'), e[0])
+      catch
+        call assert_report('Failed to run shell command, shell: ' .. e[0])
+      finally
+        bwipe!
+      endtry
     endif
   endfor
   set shell& shellcmdflag& shellpipe& shellquote&
@@ -149,6 +158,8 @@
   " ".*\\\\[^\\\\]*$"
   let shells = [['cmd', '/c', '\\', '/'],
         \ ['powershell', '-Command', '\\', '/'],
+        \ ['pwsh', '-Command', '\\', '/'],
+        \ ['pwsh', '-c', '\\', '/'],
         \ ['sh', '-c', '/', '/']]
   for e in shells
     exe 'set shell=' .. e[0] .. ' | set shellcmdflag=' .. e[1]
diff --git a/src/version.c b/src/version.c
index 3c626bb..e9ad71b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3079,
+/**/
     3078,
 /**/
     3077,