patch 8.0.1719: cannot specify which Python executable configure shou…

…ld use

Problem:    Cannot specify which Python executable configure should use.
Solution:   Add --with-python-command and --with-python3-command.

src/auto/configure

@@ -802,8 +802,10 @@ enable_mzschemeinterp
with_plthome
enable_perlinterp
enable_pythoninterp
with_python_command
with_python_config_dir
enable_python3interp
with_python3_command
with_python3_config_dir
enable_tclinterp
with_tclsh
@@ -1532,8 +1534,10 @@ Optional Packages:
  --with-lua-prefix=PFX   Prefix where Lua is installed.
  --with-luajit           Link with LuaJIT instead of Lua.
  --with-plthome=PLTHOME   Use PLTHOME.
  --with-python-config-dir=PATH  Python's config directory
  --with-python3-config-dir=PATH  Python's config directory
  --with-python-command=NAME  name of the Python 2 command (default: python2 or python)
  --with-python-config-dir=PATH  Python's config directory (deprecated)
  --with-python3-command=NAME  name of the Python 3 command (default: python3 or python)
  --with-python3-config-dir=PATH  Python's config directory (deprecated)
  --with-tclsh=PATH       which tclsh to use (default: tclsh8.0)
  --with-ruby-command=RUBY  name of the Ruby command (default: ruby)
  --with-x                use the X Window System
@@ -5937,6 +5941,21 @@ if test "$enable_pythoninterp" = "yes" -o "$enable_pythoninterp" = "dynamic"; th
    as_fn_error $? "cannot use Python with tiny or small features" "$LINENO" 5
  fi

    { $as_echo "$as_me:${as_lineno-$LINENO}: checking --with-python-command argument" >&5
$as_echo_n "checking --with-python-command argument... " >&6; }


# Check whether --with-python-command was given.
if test "${with_python_command+set}" = set; then :
  withval=$with_python_command; vi_cv_path_python="$withval"; { $as_echo "$as_me:${as_lineno-$LINENO}: result: $vi_cv_path_python" >&5
$as_echo "$vi_cv_path_python" >&6; }
else
  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi


  if test "X$vi_cv_path_python" = "X"; then
    for ac_prog in python2 python
do
  # Extract the first word of "$ac_prog", so it can be a program name with args.
@@ -5982,6 +6001,7 @@ fi
  test -n "$vi_cv_path_python" && break
done

  fi
  if test "X$vi_cv_path_python" != "X"; then

        { $as_echo "$as_me:${as_lineno-$LINENO}: checking Python version" >&5
@@ -6271,6 +6291,21 @@ if test "$enable_python3interp" = "yes" -o "$enable_python3interp" = "dynamic";
    as_fn_error $? "cannot use Python with tiny or small features" "$LINENO" 5
  fi

    { $as_echo "$as_me:${as_lineno-$LINENO}: checking --with-python3-command argument" >&5
$as_echo_n "checking --with-python3-command argument... " >&6; }


# Check whether --with-python3-command was given.
if test "${with_python3_command+set}" = set; then :
  withval=$with_python3_command; vi_cv_path_python3="$withval"; { $as_echo "$as_me:${as_lineno-$LINENO}: result: $vi_cv_path_python3" >&5
$as_echo "$vi_cv_path_python3" >&6; }
else
  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi


  if test "X$vi_cv_path_python3" = "X"; then
    for ac_prog in python3 python
do
  # Extract the first word of "$ac_prog", so it can be a program name with args.
@@ -6316,6 +6351,7 @@ fi
  test -n "$vi_cv_path_python3" && break
done

  fi
  if test "X$vi_cv_path_python3" != "X"; then

        { $as_echo "$as_me:${as_lineno-$LINENO}: checking Python version" >&5

src/configure.ac

@@ -1117,7 +1117,15 @@ if test "$enable_pythoninterp" = "yes" -o "$enable_pythoninterp" = "dynamic"; th
  fi

  dnl -- find the python executable
  AC_PATH_PROGS(vi_cv_path_python, python2 python)
  AC_MSG_CHECKING(--with-python-command argument)
  AC_SUBST(vi_cv_path_python)
  AC_ARG_WITH(python-command, [  --with-python-command=NAME  name of the Python 2 command (default: python2 or python)],
	vi_cv_path_python="$withval"; AC_MSG_RESULT($vi_cv_path_python),
	AC_MSG_RESULT(no))

  if test "X$vi_cv_path_python" = "X"; then
    AC_PATH_PROGS(vi_cv_path_python, python2 python)
  fi
  if test "X$vi_cv_path_python" != "X"; then

    dnl -- get its version number
@@ -1156,7 +1164,7 @@ if test "$enable_pythoninterp" = "yes" -o "$enable_pythoninterp" = "dynamic"; th
      dnl -- where the Python implementation library archives are

      AC_ARG_WITH(python-config-dir,
	[  --with-python-config-dir=PATH  Python's config directory],
	[  --with-python-config-dir=PATH  Python's config directory (deprecated)],
	[ vi_cv_path_python_conf="${withval}"; have_python_config_dir=1 ] )

      AC_CACHE_CHECK(Python's configuration directory,vi_cv_path_python_conf,
@@ -1343,7 +1351,15 @@ if test "$enable_python3interp" = "yes" -o "$enable_python3interp" = "dynamic";
  fi

  dnl -- find the python3 executable
  AC_PATH_PROGS(vi_cv_path_python3, python3 python)
  AC_MSG_CHECKING(--with-python3-command argument)
  AC_SUBST(vi_cv_path_python3)
  AC_ARG_WITH(python3-command, [  --with-python3-command=NAME  name of the Python 3 command (default: python3 or python)],
	vi_cv_path_python3="$withval"; AC_MSG_RESULT($vi_cv_path_python3),
	AC_MSG_RESULT(no))

  if test "X$vi_cv_path_python3" = "X"; then
    AC_PATH_PROGS(vi_cv_path_python3, python3 python)
  fi
  if test "X$vi_cv_path_python3" != "X"; then

    dnl -- get its version number
@@ -1393,7 +1409,7 @@ if test "$enable_python3interp" = "yes" -o "$enable_python3interp" = "dynamic";
      dnl -- where the Python implementation library archives are
  
      AC_ARG_WITH(python3-config-dir,
       [  --with-python3-config-dir=PATH  Python's config directory],
       [  --with-python3-config-dir=PATH  Python's config directory (deprecated)],
       [ vi_cv_path_python3_conf="${withval}"; have_python3_config_dir=1 ] )
  
      AC_CACHE_CHECK(Python's configuration directory,vi_cv_path_python3_conf,

src/version.c

@@ -762,6 +762,8 @@ static char *(features[]) =

static int included_patches[] =
{   /* Add new patch number below this line */
/**/
    1719,
/**/
    1718,
/**/