spelling: correctly restore the selected region

An added magic linefeed should be removed again /before/ restoring
the x position, as the latter needs to be calculated from the real
last line of the region.

This fixes https://savannah.gnu.org/bugs/?49817

.
Reported-by: Mike Frysinger <vapier@gentoo.org>

src/text.c

@@ -3044,6 +3044,11 @@ const char *do_alt_speller(char *tempfile_name)
 #ifndef NANO_TINY
     if (old_mark_set) {
 	filestruct *top_save = openfile->fileage;
+
+	/* If a magicline was added, remove it again. */
+	if (added_magicline)
+	    remove_magicline();
+
 	/* Adjust the end point of the marked region for any change in
 	 * length of the region's last line. */
 	if (right_side_up)
@@ -3051,10 +3056,6 @@ const char *do_alt_speller(char *tempfile_name)
 	else
 	    openfile->mark_begin_x = strlen(openfile->filebot->data);
 
-	/* If a magicline was added, remove it again. */
-	if (added_magicline)
-	    remove_magicline();
-
 	/* Unpartition the filestruct so that it contains all the text
 	 * again.  Note that we've replaced the marked text originally
 	 * in the partition with the spell-checked marked text in the