patch 9.1.0157: Duplicate assignment in f_getregion()

Problem:  Duplicate assignment in f_getregion().
Solution: Remove the duplicate assignment.  Also improve getregion()
          docs wording and fix an unrelated typo (zeertzjq)

closes: #14154

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/builtin.txt

@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2024 Mar 06
+*builtin.txt*	For Vim version 9.1.  Last change: 2024 Mar 07
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -4280,7 +4280,7 @@ getregion({pos1}, {pos2} [, {opts}])			*getregion()*
 		{pos1} and {pos2} must both be |List|s with four numbers.
 		See |getpos()| for the format of the list.  It's possible
 		to specify positions from a different buffer, but please
-		note the limitations at |getregion-notes|
+		note the limitations at |getregion-notes|.
 
 		The optional argument {opts} is a Dict and supports the
 		following items:
@@ -4314,9 +4314,9 @@ getregion({pos1}, {pos2} [, {opts}])			*getregion()*
 		- If {pos1} and {pos2} are not in the same buffer, an empty
 		  list is returned.
 		- {pos1} and {pos2} must belong to a |bufloaded()| buffer.
-		- It is evaluated in current window context, this makes a
-		  different if a buffer is displayed in a different window and
-		  'virtualedit' or 'list' is set
+		- It is evaluated in current window context, which makes a
+		  difference if the buffer is displayed in a window with
+		  different 'virtualedit' or 'list' values.
 
 		Examples: >
 			:xnoremap <CR>

src/evalfunc.c

@@ -5546,7 +5546,6 @@ f_getregion(typval_T *argvars, typval_T *rettv)
 	// buffer not loaded
 	if (findbuf == NULL || findbuf->b_ml.ml_mfp == NULL)
 	    return;
-	save_curbuf = curbuf;
 	curbuf = findbuf;
     }
 

src/testdir/test_undo.vim

@@ -583,7 +583,7 @@ funct Test_undofile()
   endif
   call assert_equal('', undofile(''))
 
-  " Test undofile() with 'undodir' set to to an existing directory.
+  " Test undofile() with 'undodir' set to an existing directory.
   call mkdir('Xundodir')
   set undodir=Xundodir
   let cwd = getcwd()

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    157,
 /**/
     156,
 /**/