Avoid cutting in the middle of UTF-8 string.

* include/grub/charset.h (grub_getend): New function.
	* grub-core/script/function.c (grub_script_function_find): Use
	grub_getend.
	* grub-core/normal/completion.c (add_completion): Likewise.

grub-core/normal/completion.c

@@ -26,6 +26,7 @@
 #include <grub/file.h>
 #include <grub/parser.h>
 #include <grub/extcmd.h>
+#include <grub/charset.h>
 
 /* The current word.  */
 static const char *current_word;
@@ -86,6 +87,7 @@ add_completion (const char *completion, const char *extra,
 		s++;
 		t++;
 	      }
+	    s = match + grub_getend (match, s);
 
 	    *s = '\0';
 	  }

grub-core/script/function.c

@@ -20,6 +20,7 @@
 #include <grub/script_sh.h>
 #include <grub/parser.h>
 #include <grub/mm.h>
+#include <grub/charset.h>
 
 grub_script_function_t grub_script_function_list;
 
@@ -99,7 +100,14 @@ grub_script_function_find (char *functionname)
       break;
 
   if (! func)
-    grub_error (GRUB_ERR_UNKNOWN_COMMAND, "unknown command `%.20s'", functionname);
+    {
+      char tmp[21];
+      grub_strncpy (tmp, functionname, 20);
+      tmp[20] = 0;
+      /* Avoid truncating inside UTF-8 character.  */
+      tmp[grub_getend (tmp, tmp + grub_strlen (tmp))] = 0;
+      grub_error (GRUB_ERR_UNKNOWN_COMMAND, "unknown command `%s'", tmp);
+    }
 
   return func;
 }