src/regex-emacs.c (POS_AS_IN_BUFFER): Delete macro

That macro added 1 to buffer positions because:

    Strings are 0-indexed, buffers are 1-indexed

but the reality is that this 1 was added to the regexp engine's "byte
offsets" which are not 1-based byte positions as used throughout
the rest of Emacs, but they are BEGV_BYTE-relative offsets, so the two
did not cancel out.

* src/regex-emacs.c (PTR_TO_OFFSET, POS_AS_IN_BUFFER): Delete macros;
use `POINTER_TO_OFFSET` instead.
(re_search_2, re_match_2, re_match_2_internal): Adjust accordingly.
* src/syntax.h (SYNTAX_TABLE_BYTE_TO_CHAR): Don't remove 1 from buffer
byteoffsets now that `POS_AS_IN_BUFFER` doesn't add it any more.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/syntax.h b/src/syntax.h
index aefe4dafa42..05d58eff05f 100644
--- a/src/syntax.h
+++ b/src/syntax.h
@@ -145,7 +145,7 @@ extern bool syntax_prefix_flag_p (int c);
 
 extern unsigned char const syntax_spec_code[0400];
 
-/* Convert the byte offset BYTEPOS into a character position,
+/* Convert the regexp BYTEOFFSET into a character position,
    for the object recorded in gl_state with SETUP_SYNTAX_TABLE_FOR_OBJECT.
 
    The value is meant for use in code that does nothing when
@@ -153,19 +153,19 @@ extern unsigned char const syntax_spec_code[0400];
    for speed.  */
 
 INLINE ptrdiff_t
-SYNTAX_TABLE_BYTE_TO_CHAR (ptrdiff_t bytepos)
+SYNTAX_TABLE_BYTE_TO_CHAR (ptrdiff_t byteoffset)
 {
   return (! parse_sexp_lookup_properties
           ? 0
           : STRINGP (gl_state.object)
-          ? string_byte_to_char (gl_state.object, bytepos)
+          ? string_byte_to_char (gl_state.object, byteoffset)
           : BUFFERP (gl_state.object)
           ? ((buf_bytepos_to_charpos
               (XBUFFER (gl_state.object),
-               (bytepos + BUF_BEGV_BYTE (XBUFFER (gl_state.object)) - 1))))
+               (byteoffset + BUF_BEGV_BYTE (XBUFFER (gl_state.object))))))
           : NILP (gl_state.object)
-          ? BYTE_TO_CHAR (bytepos + BEGV_BYTE - 1)
-          : bytepos);
+          ? BYTE_TO_CHAR (byteoffset + BEGV_BYTE)
+          : byteoffset);
 }
 
 /* Make syntax table state (gl_state) good for CHARPOS, assuming it is