(Fchar_before): Check POS in valid range

before calling CHAR_TO_BYTE.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/editfns.c b/src/editfns.c
index bb805419293..3ad14164a8f 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -589,6 +589,8 @@ is returned as a character.")
     pos_byte = PT_BYTE;
   else if (MARKERP (pos))
     pos_byte = marker_byte_position (pos);
+  else if (pos <= BEGV || pos > ZV)
+    return Qnil;
   else
     {
       CHECK_NUMBER_COERCE_MARKER (pos, 0);
@@ -596,9 +598,6 @@ is returned as a character.")
       pos_byte = CHAR_TO_BYTE (XINT (pos));
     }
 
-  if (pos_byte <= BEGV_BYTE || pos_byte > ZV_BYTE)
-    return Qnil;
-
   if (!NILP (current_buffer->enable_multibyte_characters))
     {
       DEC_POS (pos_byte);