patch 8.2.3071: shell options are not set properly for PowerShell

Problem:    Shell options are not set properly for PowerShell.
Solution:   Use better option defaults. (Mike Willams, closes #8459)

runtime/doc/eval.txt

@@ -9878,9 +9878,11 @@ sha256({string})						*sha256()*
 
 shellescape({string} [, {special}])			*shellescape()*
 		Escape {string} for use as a shell command argument.
-		On MS-Windows, when 'shellslash' is not set, it will enclose
+		On MS-Windows, when the 'shell' contains powershell then it
-		{string} in double quotes and double all double quotes within
+		will enclose {string} in single quotes and will double up all
-		{string}.
+		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}.
 		Otherwise it will enclose {string} in single quotes and
 		replace all "'" with "'\''".
 
@@ -11040,7 +11042,8 @@ tempname()					*tempname()* *temp-file-name*
 			: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 '-'.
+		option is set or when 'shellcmdflag' starts with '-' except
+		when when 'shell' contains powershell.
 
 
 term_ functions are documented here: |terminal-function-details|

runtime/doc/options.txt

@@ -6594,23 +6594,25 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'shellcmdflag'* *'shcf'*
 'shellcmdflag' 'shcf'	string	(default: "-c";
-				 Win32, when 'shell' does not contain "sh"
+				 Win32, when 'shell' contains "powershell":
+				 "-Command", or when it does not contain "sh"
 				 somewhere: "/c")
 			global
 	Flag passed to the shell to execute "!" and ":!" commands; e.g.,
-	"bash.exe -c ls" or "cmd.exe /c dir".  For MS-Windows, the default is
+	"bash.exe -c ls", "powershell.exe -Command dir", or "cmd.exe /c dir".
-	set according to the value of 'shell', to reduce the need to set this
+	For MS-Windows, the default is set according to the value of 'shell',
-	option by the user.
+	to reduce the need to set this option by the user.
 	On Unix it can have more than one flag.  Each white space separated
 	part is passed as an argument to the shell command.
 	See |option-backslash| about including spaces and backslashes.
-	Also see |dos-shell| for MS-Windows.
+	Also see |dos-shell| and |dos-powershell| for MS-Windows.
 	This option cannot be set from a |modeline| or in the |sandbox|, for
 	security reasons.
 
 						*'shellpipe'* *'sp'*
-'shellpipe' 'sp'	string	(default ">", ">%s 2>&1", "| tee", "|& tee" or
+'shellpipe' 'sp'	string	(default ">", ">%s 2>&1", "| tee", "|& tee"
-				 "2>&1| tee")
+				 "2>&1| tee", or
+				 "2>&1 | Out-File -Encoding default")
 			global
 			{not available when compiled without the |+quickfix|
 			feature}
@@ -6620,9 +6622,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	The name of the temporary file can be represented by "%s" if necessary
 	(the file name is appended automatically if no %s appears in the value
 	of this option).
-	For the Amiga the default is ">".  For MS-Windows the default is
+	For the Amiga the default is ">".  For MS-Windows using powershell the
-	">%s 2>&1".  The output is directly saved in a file and not echoed to
+	default is "2>&1 | Out-File -Encoding default", otherwise the default
-	the screen.
+	is ">%s 2>&1".  The output is directly saved in a file and not echoed
+	to the screen.
 	For Unix the default is "| tee".  The stdout of the compiler is saved
 	in a file and echoed to the screen.  If the 'shell' option is "csh" or
 	"tcsh" after initializations, the default becomes "|& tee".  If the
@@ -6645,8 +6648,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	security reasons.
 
 						*'shellquote'* *'shq'*
-'shellquote' 'shq'	string	(default: ""; Win32, when 'shell'
+'shellquote' 'shq'	string	(default: ""; Win32, when 'shell' does not
-					contains "sh" somewhere: "\"")
+				 contain powershell but contains "sh"
+				 somewhere: "\"")
 			global
 	Quoting character(s), put around the command passed to the shell, for
 	the "!" and ":!" commands.  The redirection is kept outside of the
@@ -6661,7 +6665,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 	security reasons.
 
 						*'shellredir'* *'srr'*
-'shellredir' 'srr'	string	(default ">", ">&" or ">%s 2>&1")
+'shellredir' 'srr'	string	(default ">", ">&", ">%s 2>&1", or
+				 "2>&1 | Out-File -Encoding default")
 			global
 	String to be used to put the output of a filter command in a temporary
 	file.  See also |:!|.  See |option-backslash| about including spaces
@@ -6674,8 +6679,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	'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
-	additionally "cmd" is checked for, which makes the default ">%s 2>&1".
+	additionally "cmd" is checked for, which makes the default ">%s 2>&1",
-	Also, the same names with ".exe" appended are checked for.
+	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.
 	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
@@ -6690,9 +6697,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 			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.  Backward
+	useful when a Unix-like shell is used instead of cmd.exe or
-	slashes can still be typed, but they are changed to forward slashes by
+	powershell.exe.  Backward slashes can still be typed, but they are
-	Vim.
+	changed to forward slashes by Vim.
 	Note that setting or resetting this option has no effect for some
 	existing file names, thus this option needs to be set before opening
 	any file for best results.  This might change in the future.
@@ -6746,6 +6753,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 						*'shellxquote'* *'sxq'*
 'shellxquote' 'sxq'	string	(default: "";
 					for Win32, when 'shell' is cmd.exe: "("
+					for Win32, when 'shell' is
+					powershell.exe: "\""
 					for Win32, when 'shell' contains "sh"
 					somewhere: "\""
 					for Unix, when using system(): "\"")
@@ -6758,11 +6767,12 @@ A jump table for the options with a short description can be found at |Q_op|.
 	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 which automatically
+	useful for on Win32 version, either for cmd.exe and powershell.exe
-	strips off the first and last quote on a command, or 3rd-party shells
+	which automatically strips off the first and last quote on a command,
-	such as the MKS Korn Shell or bash, where it should be "\"".  The
+	or 3rd-party shells such as the MKS Korn Shell or bash, where it
-	default is adjusted according the value of 'shell', to reduce the need
+	should be "\"".  The default is adjusted according the value of
-	to set this option by the user.  See |dos-shell|.
+	'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
 	security reasons.
 

runtime/doc/os_dos.txt

@@ -17,6 +17,7 @@ versions of Vim.  Also see |os_win32.txt| and |os_msdos.txt|.
 7. Interrupting			|dos-CTRL-Break|
 8. Temp files			|dos-temp-files|
 9. Shell option default		|dos-shell|
+10. PowerShell			|dos-powershell|
 
 ==============================================================================
 1. File locations					*dos-locations*
@@ -297,8 +298,46 @@ For Win32 as:
 	<shell> -c "command name >file"
 For DOS 32 bit, DJGPP does this internally somehow.
 
-When starting up, Vim checks for the presence of "sh" anywhere in the 'shell'
+When starting up, if Vim does not recognise a standard Windows shell it checks
-option.  If it is present, Vim sets the 'shellcmdflag' and 'shellquote' or
+for the presence of "sh" anywhere in the 'shell' option.  If it is present,
-'shellxquote' options will be set as described above.
+Vim sets the 'shellcmdflag' and 'shellquote' or 'shellxquote' options will be
+set as described above.
+
+==============================================================================
+10. PowerShell						*dos-powershell*
+
+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:
+
+'shellcmdflag'	-Command
+'shellxquote'	"
+'shellpipe'	2>&1 | Out-File -Encoding default
+'shellredir'	2>&1 | Out-File -Encoding default
+
+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.
+
+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.
+
+The 'shellpipe' and 'shellredir' option values re-encode the UTF-16le output
+from Windows PowerShell 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)
+	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.
 
  vim:tw=78:ts=8:noet:ft=help:norl:

src/fileio.c

@@ -5245,9 +5245,10 @@ vim_tempname(
 
     // Backslashes in a temp file name cause problems when filtering with
     // "sh".  NOTE: This also checks 'shellcmdflag' to help those people who
-    // didn't set 'shellslash'.
+    // didn't set 'shellslash' but only if not using PowerShell.
     retval = utf16_to_enc(itmp, NULL);
-    if (*p_shcf == '-' || p_ssl)
+    if ((strstr((char *)gettail(p_sh), "powershell") == NULL
+						&& *p_shcf == '-') || p_ssl)
 	for (p = retval; *p; ++p)
 	    if (*p == '\\')
 		*p = '/';

src/misc2.c

@@ -1396,7 +1396,9 @@ csh_like_shell(void)
 /*
  * Escape "string" for use as a shell argument with system().
  * This uses single quotes, except when we know we need to use double quotes
- * (MS-DOS and MS-Windows without 'shellslash' set).
+ * (MS-DOS and MS-Windows not using PowerShell and without 'shellslash' set).
+ * PowerShell also uses a novel escaping for enclosed single quotes - double
+ * them up.
  * Escape a newline, depending on the 'shell' option.
  * When "do_special" is TRUE also replace "!", "%", "#" and things starting
  * with "<" like "<cfile>".
@@ -1412,6 +1414,10 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
     char_u	*escaped_string;
     int		l;
     int		csh_like;
+# ifdef MSWIN
+    int		powershell;
+    int		double_quotes;
+# endif
 
     // Only csh and similar shells expand '!' within single quotes.  For sh and
     // the like we must not put a backslash before it, it will be taken
@@ -1419,12 +1425,18 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
     // Csh also needs to have "\n" escaped twice when do_special is set.
     csh_like = csh_like_shell();
 
+# ifdef MSWIN
+    // PowerShell only accepts single quotes so override p_ssl.
+    powershell = strstr((char *)gettail(p_sh), "powershell") != NULL;
+    double_quotes = !powershell && !p_ssl;
+# endif
+
     // First count the number of extra bytes required.
     length = (unsigned)STRLEN(string) + 3;  // two quotes and a trailing NUL
     for (p = string; *p != NUL; MB_PTR_ADV(p))
     {
 # ifdef MSWIN
-	if (!p_ssl)
+	if (double_quotes)
 	{
 	    if (*p == '"')
 		++length;		// " -> ""
@@ -1432,7 +1444,14 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
 	else
 # endif
 	if (*p == '\'')
-	    length += 3;		// ' => '\''
+	{
+# ifdef MSWIN
+	    if (powershell)
+		length +=2;		// ' => ''
+	    else
+# endif
+		length += 3;		// ' => '\''
+	}
 	if ((*p == '\n' && (csh_like || do_newline))
 		|| (*p == '!' && (csh_like || do_special)))
 	{
@@ -1455,7 +1474,7 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
 
 	// add opening quote
 # ifdef MSWIN
-	if (!p_ssl)
+	if (double_quotes)
 	    *d++ = '"';
 	else
 # endif
@@ -1464,7 +1483,7 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
 	for (p = string; *p != NUL; )
 	{
 # ifdef MSWIN
-	    if (!p_ssl)
+	    if (double_quotes)
 	    {
 		if (*p == '"')
 		{
@@ -1478,10 +1497,20 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
 # endif
 	    if (*p == '\'')
 	    {
-		*d++ = '\'';
+# ifdef MSWIN
-		*d++ = '\\';
+		if (powershell)
-		*d++ = '\'';
+		{
-		*d++ = '\'';
+		    *d++ = '\'';
+		    *d++ = '\'';
+		}
+		else
+# endif
+		{
+		    *d++ = '\'';
+		    *d++ = '\\';
+		    *d++ = '\'';
+		    *d++ = '\'';
+		}
 		++p;
 		continue;
 	    }
@@ -1507,7 +1536,7 @@ vim_strsave_shellescape(char_u *string, int do_special, int do_newline)
 
 	// add terminating quote and finish with a NUL
 # ifdef MSWIN
-	if (!p_ssl)
+	if (double_quotes)
 	    *d++ = '"';
 	else
 # endif

src/option.c

@@ -932,6 +932,27 @@ set_init_3(void)
 		options[idx_srr].def_val[VI_DEFAULT] = p_srr;
 	    }
 	}
+# ifdef MSWIN
+	// PowerShell 5.1/.NET outputs UTF-16 with BOM so re-encode to the
+	// current codepage
+	else if (   fnamecmp(p, "powershell") == 0
+		    || fnamecmp(p, "powershell.exe") == 0
+		)
+	{
+# if defined(FEAT_QUICKFIX)
+		if (do_sp)
+		{
+		    p_sp = (char_u *)"2>&1 | Out-File -Encoding default";
+		    options[idx_sp].def_val[VI_DEFAULT] = p_sp;
+		}
+# endif
+		if (do_srr)
+		{
+		    p_srr = (char_u *)"2>&1 | Out-File -Encoding default";
+		    options[idx_srr].def_val[VI_DEFAULT] = p_srr;
+		}
+	}
+#endif
 	else
 	    // Always use POSIX shell style redirection if we reach this
 	    if (       fnamecmp(p, "sh") == 0
@@ -984,11 +1005,35 @@ set_init_3(void)
      * Set 'shellcmdflag', 'shellxquote', and 'shellquote' depending on the
      * 'shell' option.
      * This is done after other initializations, where 'shell' might have been
-     * set, but only if they have not been set before.  Default for p_shcf is
+     * set, but only if they have not been set before.
-     * "/c", for p_shq is "".  For "sh" like  shells it is changed here to
+     * Default values depend on shell (cmd.exe is default shell):
-     * "-c" and "\"".  And for Win32 we need to set p_sxq instead.
+     *
+     *			    p_shcf	p_sxq
+     * cmd.exe          -   "/c"	"("
+     * powershell.exe   -   "-Command"	"\""
+     * "sh" like shells -   "-c"	"\""
+     *
+     * For Win32 p_sxq is set instead of p_shq to include shell redirection.
      */
-    if (strstr((char *)gettail(p_sh), "sh") != NULL)
+    if (strstr((char *)gettail(p_sh), "powershell") != NULL)
+    {
+	int	idx_opt;
+
+	idx_opt = findoption((char_u *)"shcf");
+	if (idx_opt >= 0 && !(options[idx_opt].flags & P_WAS_SET))
+	{
+	    p_shcf = (char_u*)"-Command";
+	    options[idx_opt].def_val[VI_DEFAULT] = p_shcf;
+	}
+
+	idx_opt = findoption((char_u *)"sxq");
+	if (idx_opt >= 0 && !(options[idx_opt].flags & P_WAS_SET))
+	{
+	    p_sxq = (char_u*)"\"";
+	    options[idx_opt].def_val[VI_DEFAULT] = p_sxq;
+	}
+    }
+    else if (strstr((char *)gettail(p_sh), "sh") != NULL)
     {
 	int	idx3;
 

src/os_win32.c

@@ -2142,7 +2142,8 @@ executable_exists(char *name, char_u **path, int use_path, int use_pathext)
 	return FALSE;
 
     // Using the name directly when a Unix-shell like 'shell'.
-    if (strstr((char *)gettail(p_sh), "sh") != NULL)
+    if (strstr((char *)gettail(p_sh), "powershell") == NULL
+				&& strstr((char *)gettail(p_sh), "sh") != NULL)
 	noext = TRUE;
 
     if (use_pathext)

src/testdir/test_shell.vim

@@ -24,8 +24,10 @@ func Test_shell_options()
   if has('win32')
     let shells += [['cmd', '/c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', ''],
           \ ['cmd.exe', '/c', '>%s 2>&1', '', '>%s 2>&1', '"&|<>()@^', '('],
-          \ ['powershell.exe', '-c', '>', '', '>', '"&|<>()@^', '"'],
+          \ ['powershell.exe', '-Command', '2>&1 | Out-File -Encoding default',
-          \ ['powershell', '-c', '>', '', '>', '"&|<>()@^', '"'],
+          \           '', '2>&1 | Out-File -Encoding default', '"&|<>()@^', '"'],
+          \ ['powershell', '-Command', '2>&1 | Out-File -Encoding default', '',
+          \               '2>&1 | Out-File -Encoding default', '"&|<>()@^', '"'],
           \ ['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', '"&|<>()@^', '"'],
@@ -58,6 +60,9 @@ func Test_shell_options()
     if e[0] =~# '.*csh$' || e[0] =~# '.*csh.exe$'
       let str1 = "'cmd \"arg1\" '\\''arg2'\\'' \\!%#'"
       let str2 = "'cmd \"arg1\" '\\''arg2'\\'' \\\\!\\%\\#'"
+    elseif e[0] =~# '.*powershell$' || e[0] =~# '.*powershell.exe$'
+      let str1 = "'cmd \"arg1\" ''arg2'' !%#'"
+      let str2 = "'cmd \"arg1\" ''arg2'' \\!\\%\\#'"
     else
       let str1 = "'cmd \"arg1\" '\\''arg2'\\'' !%#'"
       let str2 = "'cmd \"arg1\" '\\''arg2'\\'' \\!\\%\\#'"
@@ -135,6 +140,28 @@ func Test_shellescape()
   let &shell = save_shell
 endfunc
 
+" Test for 'shellslash'
+func Test_shellslash()
+  CheckOption shellslash
+  let save_shellslash = &shellslash
+  " The shell and cmdflag, and expected slash in tempname with shellslash set or
+  " unset.  The assert checks the file separator before the leafname.
+  " ".*\\\\[^\\\\]*$"
+  let shells = [['cmd', '/c', '\\', '/'],
+        \ ['powershell', '-Command', '\\', '/'],
+        \ ['sh', '-c', '/', '/']]
+  for e in shells
+    exe 'set shell=' .. e[0] .. ' | set shellcmdflag=' .. e[1]
+    set noshellslash
+    let file = tempname()
+    call assert_match('^.\+' .. e[2] .. '[^' .. e[2] .. ']\+$', file, e[0] .. ' ' .. e[1] .. ' nossl')
+    set shellslash
+    let file = tempname()
+    call assert_match('^.\+' .. e[3] .. '[^' .. e[3] .. ']\+$', file, e[0] .. ' ' .. e[1] .. ' ssl')
+  endfor
+  let &shellslash = save_shellslash
+endfunc
+
 " Test for 'shellxquote'
 func Test_shellxquote()
   CheckUnix

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3071,
 /**/
     3070,
 /**/