* xdisp.c (init_iterator): Simplify because both character and byte

positions are either specified or -1.  Add eassert.  Adjust comment.

2 files changed, 8 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 7642393bb01..e23f0167339 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-13  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        * xdisp.c (init_iterator): Simplify because both character and byte
+        positions are either specified or -1.  Add eassert.  Adjust comment.
+
 2013-03-13  Paul Eggert  <eggert@cs.ucla.edu>
 
         Static checking by Sun C 5.12.
diff --git a/src/xdisp.c b/src/xdisp.c
index 511a5eeb2c3..a5bba1a81cd 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -2550,7 +2550,7 @@ markpos_of_region (void)
    at character position CHARPOS.  CHARPOS < 0 means that no buffer
    position is specified which is useful when the iterator is assigned
    a position later.  BYTEPOS is the byte position corresponding to
-   CHARPOS.  BYTEPOS < 0 means compute it from CHARPOS.
+   CHARPOS.
 
    If ROW is not null, calls to produce_glyphs with IT as parameter
    will produce glyphs in that row.
@@ -2828,18 +2828,14 @@ init_iterator (struct it *it, struct window *w,
   if (charpos >= BUF_BEG (current_buffer))
     {
       it->end_charpos = ZV;
+      eassert (charpos == BYTE_TO_CHAR (bytepos));
       IT_CHARPOS (*it) = charpos;
+      IT_BYTEPOS (*it) = bytepos;
 
       /* We will rely on `reseat' to set this up properly, via
          handle_face_prop.  */
       it->face_id = it->base_face_id;
 
-      /* Compute byte position if not specified.  */
-      if (bytepos < charpos)
-        IT_BYTEPOS (*it) = CHAR_TO_BYTE (charpos);
-      else
-        IT_BYTEPOS (*it) = bytepos;
-
       it->start = it->current;
       /* Do we need to reorder bidirectional text?  Not if this is a
          unibyte buffer: by definition, none of the single-byte