Merge remote-tracking branch 'savannah/master' into HEAD

23 files changed, 216 insertions, 265 deletions

diff --git a/src/bignum.h b/src/bignum.h
index 0c2541a9dc7..ad9021f15fd 100644
--- a/src/bignum.h
+++ b/src/bignum.h
@@ -55,7 +55,7 @@ extern void emacs_mpz_mul_2exp (mpz_t, mpz_t const, EMACS_INT)
   ARG_NONNULL ((1, 2));
 extern void emacs_mpz_pow_ui (mpz_t, mpz_t const, unsigned long)
   ARG_NONNULL ((1, 2));
-extern double mpz_get_d_rounded (mpz_t const);
+extern double mpz_get_d_rounded (mpz_t const) ATTRIBUTE_CONST;
 
 INLINE_HEADER_BEGIN
 
diff --git a/src/buffer.c b/src/buffer.c
index cc7d4e4817c..70598a7a22a 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -131,6 +131,23 @@ CHECK_OVERLAY (Lisp_Object x)
   CHECK_TYPE (OVERLAYP (x), Qoverlayp, x);
 }
 
+/* Convert the position POS to an EMACS_INT that fits in a fixnum.
+   Yield POS's value if POS is already a fixnum, POS's marker position
+   if POS is a marker, and MOST_NEGATIVE_FIXNUM or
+   MOST_POSITIVE_FIXNUM if POS is a negative or positive bignum.
+   Signal an error if POS is not of the proper form.  */
+
+EMACS_INT
+fix_position (Lisp_Object pos)
+{
+  if (FIXNUMP (pos))
+    return XFIXNUM (pos);
+  if (MARKERP (pos))
+    return marker_position (pos);
+  CHECK_TYPE (BIGNUMP (pos), Qinteger_or_marker_p, pos);
+  return !NILP (Fnatnump (pos)) ? MOST_POSITIVE_FIXNUM : MOST_NEGATIVE_FIXNUM;
+}
+
 /* These setters are used only in this file, so they can be private.
    The public setters are inline functions defined in buffer.h.  */
 static void
@@ -2257,19 +2274,20 @@ so the buffer is truly empty after this.  */)
 }
 
 void
-validate_region (register Lisp_Object *b, register Lisp_Object *e)
+validate_region (Lisp_Object *b, Lisp_Object *e)
 {
-  CHECK_FIXNUM_COERCE_MARKER (*b);
-  CHECK_FIXNUM_COERCE_MARKER (*e);
+  EMACS_INT beg = fix_position (*b), end = fix_position (*e);
 
-  if (XFIXNUM (*b) > XFIXNUM (*e))
+  if (end < beg)
     {
-      Lisp_Object tem;
-      tem = *b;  *b = *e;  *e = tem;
+      EMACS_INT tem = beg;  beg = end;  end = tem;
     }
 
-  if (! (BEGV <= XFIXNUM (*b) && XFIXNUM (*e) <= ZV))
+  if (! (BEGV <= beg && end <= ZV))
     args_out_of_range_3 (Fcurrent_buffer (), *b, *e);
+
+  *b = make_fixnum (beg);
+  *e = make_fixnum (end);
 }
 
 /* Advance BYTE_POS up to a character boundary
diff --git a/src/buffer.h b/src/buffer.h
index fd05fdd37de..31f497ea40a 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1150,6 +1150,8 @@ extern Lisp_Object interval_insert_behind_hooks;
 extern Lisp_Object interval_insert_in_front_hooks;
 
 
+extern EMACS_INT fix_position (Lisp_Object);
+#define CHECK_FIXNUM_COERCE_MARKER(x) ((x) = make_fixnum (fix_position (x)))
 extern void delete_all_overlays (struct buffer *);
 extern void reset_buffer (struct buffer *);
 extern void compact_buffer (struct buffer *);
diff --git a/src/character.c b/src/character.c
index 5d419a2e836..d71cb3f145c 100644
--- a/src/character.c
+++ b/src/character.c
@@ -931,10 +931,10 @@ character is not ASCII nor 8-bit character, an error is signaled.  */)
 	}
       else
 	{
-	  CHECK_FIXNUM_COERCE_MARKER (position);
-	  if (XFIXNUM (position) < BEGV || XFIXNUM (position) >= ZV)
+	  EMACS_INT fixed_pos = fix_position (position);
+	  if (! (BEGV <= fixed_pos && fixed_pos < ZV))
 	    args_out_of_range_3 (position, make_fixnum (BEGV), make_fixnum (ZV));
-	  pos = XFIXNAT (position);
+	  pos = fixed_pos;
 	  p = CHAR_POS_ADDR (pos);
 	}
       if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
diff --git a/src/cmds.c b/src/cmds.c
index 5d7a45e65f6..c342cd88bd8 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -31,15 +31,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 static int internal_self_insert (int, EMACS_INT);
 
-DEFUN ("forward-point", Fforward_point, Sforward_point, 1, 1, 0,
-       doc: /* Return buffer position N characters after (before if N negative) point.  */)
-  (Lisp_Object n)
-{
-  CHECK_FIXNUM (n);
-
-  return make_fixnum (PT + XFIXNUM (n));
-}
-
 /* Add N to point; or subtract N if FORWARD is false.  N defaults to 1.
    Validate the new location.  Return nil.  */
 static Lisp_Object
@@ -460,7 +451,10 @@ internal_self_insert (int c, EMACS_INT n)
 	  string = concat2 (string, tem);
 	}
 
-      replace_range (PT, PT + chars_to_delete, string, 1, 1, 1, 0);
+      ptrdiff_t to;
+      if (INT_ADD_WRAPV (PT, chars_to_delete, &to))
+	to = PTRDIFF_MAX;
+      replace_range (PT, to, string, 1, 1, 1, 0);
       Fforward_char (make_fixnum (n));
     }
   else if (n > 1)
@@ -526,7 +520,6 @@ syms_of_cmds (void)
 This is run after inserting the character.  */);
   Vpost_self_insert_hook = Qnil;
 
-  defsubr (&Sforward_point);
   defsubr (&Sforward_char);
   defsubr (&Sbackward_char);
   defsubr (&Sforward_line);
diff --git a/src/coding.c b/src/coding.c
index 8b54281c0bf..0bea2a0c2bc 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -9023,23 +9023,23 @@ DEFUN ("find-coding-systems-region-internal",
     }
   else
     {
-      CHECK_FIXNUM_COERCE_MARKER (start);
-      CHECK_FIXNUM_COERCE_MARKER (end);
-      if (XFIXNUM (start) < BEG || XFIXNUM (end) > Z || XFIXNUM (start) > XFIXNUM (end))
+      EMACS_INT s = fix_position (start);
+      EMACS_INT e = fix_position (end);
+      if (! (BEG <= s && s <= e && e <= Z))
 	args_out_of_range (start, end);
       if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
 	return Qt;
-      start_byte = CHAR_TO_BYTE (XFIXNUM (start));
-      end_byte = CHAR_TO_BYTE (XFIXNUM (end));
-      if (XFIXNUM (end) - XFIXNUM (start) == end_byte - start_byte)
+      start_byte = CHAR_TO_BYTE (s);
+      end_byte = CHAR_TO_BYTE (e);
+      if (e - s == end_byte - start_byte)
 	return Qt;
 
-      if (XFIXNUM (start) < GPT && XFIXNUM (end) > GPT)
+      if (s < GPT && GPT < e)
 	{
-	  if ((GPT - XFIXNUM (start)) < (XFIXNUM (end) - GPT))
-	    move_gap_both (XFIXNUM (start), start_byte);
+	  if (GPT - s < e - GPT)
+	    move_gap_both (s, start_byte);
 	  else
-	    move_gap_both (XFIXNUM (end), end_byte);
+	    move_gap_both (e, end_byte);
 	}
     }
 
@@ -9277,25 +9277,25 @@ is nil.  */)
     }
   else
     {
-      CHECK_FIXNUM_COERCE_MARKER (start);
-      CHECK_FIXNUM_COERCE_MARKER (end);
-      if (XFIXNUM (start) < BEG || XFIXNUM (end) > Z || XFIXNUM (start) > XFIXNUM (end))
+      EMACS_INT s = fix_position (start);
+      EMACS_INT e = fix_position (end);
+      if (! (BEG <= s && s <= e && e <= Z))
 	args_out_of_range (start, end);
       if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
 	return Qnil;
-      start_byte = CHAR_TO_BYTE (XFIXNUM (start));
-      end_byte = CHAR_TO_BYTE (XFIXNUM (end));
-      if (XFIXNUM (end) - XFIXNUM (start) == end_byte - start_byte)
+      start_byte = CHAR_TO_BYTE (s);
+      end_byte = CHAR_TO_BYTE (e);
+      if (e - s == end_byte - start_byte)
 	return Qnil;
 
-      if (XFIXNUM (start) < GPT && XFIXNUM (end) > GPT)
+      if (s < GPT && GPT < e)
 	{
-	  if ((GPT - XFIXNUM (start)) < (XFIXNUM (end) - GPT))
-	    move_gap_both (XFIXNUM (start), start_byte);
+	  if (GPT - s < e - GPT)
+	    move_gap_both (s, start_byte);
 	  else
-	    move_gap_both (XFIXNUM (end), end_byte);
+	    move_gap_both (e, end_byte);
 	}
-      pos = XFIXNUM (start);
+      pos = s;
     }
 
   list = Qnil;
diff --git a/src/composite.c b/src/composite.c
index 84de334ce0d..a00a4541f5e 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -1839,27 +1839,24 @@ See `find-composition' for more details.  */)
   ptrdiff_t start, end, from, to;
   int id;
 
-  CHECK_FIXNUM_COERCE_MARKER (pos);
+  EMACS_INT fixed_pos = fix_position (pos);
   if (!NILP (limit))
-    {
-      CHECK_FIXNUM_COERCE_MARKER (limit);
-      to = min (XFIXNUM (limit), ZV);
-    }
+    to = clip_to_bounds (PTRDIFF_MIN, fix_position (limit), ZV);
   else
     to = -1;
 
   if (!NILP (string))
     {
       CHECK_STRING (string);
-      if (XFIXNUM (pos) < 0 || XFIXNUM (pos) > SCHARS (string))
+      if (! (0 <= fixed_pos && fixed_pos <= SCHARS (string)))
 	args_out_of_range (string, pos);
     }
   else
     {
-      if (XFIXNUM (pos) < BEGV || XFIXNUM (pos) > ZV)
+      if (! (BEGV <= fixed_pos && fixed_pos <= ZV))
 	args_out_of_range (Fcurrent_buffer (), pos);
     }
-  from = XFIXNUM (pos);
+  from = fixed_pos;
 
   if (!find_composition (from, to, &start, &end, &prop, string))
     {
@@ -1870,12 +1867,12 @@ See `find-composition' for more details.  */)
 	return list3 (make_fixnum (start), make_fixnum (end), gstring);
       return Qnil;
     }
-  if ((end <= XFIXNUM (pos) || start > XFIXNUM (pos)))
+  if (! (start <= fixed_pos && fixed_pos < end))
     {
       ptrdiff_t s, e;
 
       if (find_automatic_composition (from, to, &s, &e, &gstring, string)
-	  && (e <= XFIXNUM (pos) ? e > end : s < start))
+	  && (e <= fixed_pos ? e > end : s < start))
 	return list3 (make_fixnum (s), make_fixnum (e), gstring);
     }
   if (!composition_valid_p (start, end, prop))
diff --git a/src/data.c b/src/data.c
index 2820f647981..b53b8409b59 100644
--- a/src/data.c
+++ b/src/data.c
@@ -2368,6 +2368,24 @@ bool-vector.  IDX starts at 0.  */)
 
 /* Arithmetic functions */
 
+static Lisp_Object
+check_integer_coerce_marker (Lisp_Object x)
+{
+  if (MARKERP (x))
+    return make_fixnum (marker_position (x));
+  CHECK_TYPE (INTEGERP (x), Qinteger_or_marker_p, x);
+  return x;
+}
+
+static Lisp_Object
+check_number_coerce_marker (Lisp_Object x)
+{
+  if (MARKERP (x))
+    return make_fixnum (marker_position (x));
+  CHECK_TYPE (NUMBERP (x), Qnumber_or_marker_p, x);
+  return x;
+}
+
 Lisp_Object
 arithcompare (Lisp_Object num1, Lisp_Object num2,
 	      enum Arith_Comparison comparison)
@@ -2376,8 +2394,8 @@ arithcompare (Lisp_Object num1, Lisp_Object num2,
   bool lt, eq = true, gt;
   bool test;
 
-  CHECK_NUMBER_COERCE_MARKER (num1);
-  CHECK_NUMBER_COERCE_MARKER (num2);
+  num1 = check_number_coerce_marker (num1);
+  num2 = check_number_coerce_marker (num2);
 
   /* If the comparison is mostly done by comparing two doubles,
      set LT, EQ, and GT to the <, ==, > results of that comparison,
@@ -2779,9 +2797,7 @@ floatop_arith_driver (enum arithop code, ptrdiff_t nargs, Lisp_Object *args,
       argnum++;
       if (argnum == nargs)
 	return make_float (accum);
-      Lisp_Object val = args[argnum];
-      CHECK_NUMBER_COERCE_MARKER (val);
-      next = XFLOATINT (val);
+      next = XFLOATINT (check_number_coerce_marker (args[argnum]));
     }
 }
 
@@ -2843,8 +2859,7 @@ bignum_arith_driver (enum arithop code, ptrdiff_t nargs, Lisp_Object *args,
       argnum++;
       if (argnum == nargs)
 	return make_integer_mpz ();
-      val = args[argnum];
-      CHECK_NUMBER_COERCE_MARKER (val);
+      val = check_number_coerce_marker (args[argnum]);
       if (FLOATP (val))
 	return float_arith_driver (code, nargs, args, argnum,
 				   mpz_get_d_rounded (*accum), val);
@@ -2873,8 +2888,7 @@ arith_driver (enum arithop code, ptrdiff_t nargs, Lisp_Object *args,
 	argnum++;
 	if (argnum == nargs)
 	  return make_int (accum);
-	val = args[argnum];
-	CHECK_NUMBER_COERCE_MARKER (val);
+	val = check_number_coerce_marker (args[argnum]);
 
 	/* Set NEXT to the next value if it fits, else exit the loop.  */
 	intmax_t next;
@@ -2921,8 +2935,7 @@ usage: (+ &rest NUMBERS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (0);
-  Lisp_Object a = args[0];
-  CHECK_NUMBER_COERCE_MARKER (a);
+  Lisp_Object a = check_number_coerce_marker (args[0]);
   return nargs == 1 ? a : arith_driver (Aadd, nargs, args, a);
 }
 
@@ -2935,8 +2948,7 @@ usage: (- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (0);
-  Lisp_Object a = args[0];
-  CHECK_NUMBER_COERCE_MARKER (a);
+  Lisp_Object a = check_number_coerce_marker (args[0]);
   if (nargs == 1)
     {
       if (FIXNUMP (a))
@@ -2956,8 +2968,7 @@ usage: (* &rest NUMBERS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (1);
-  Lisp_Object a = args[0];
-  CHECK_NUMBER_COERCE_MARKER (a);
+  Lisp_Object a = check_number_coerce_marker (args[0]);
   return nargs == 1 ? a : arith_driver (Amult, nargs, args, a);
 }
 
@@ -2969,8 +2980,7 @@ The arguments must be numbers or markers.
 usage: (/ NUMBER &rest DIVISORS)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
-  Lisp_Object a = args[0];
-  CHECK_NUMBER_COERCE_MARKER (a);
+  Lisp_Object a = check_number_coerce_marker (args[0]);
   if (nargs == 1)
     {
       if (FIXNUMP (a))
@@ -3052,10 +3062,10 @@ integer_remainder (Lisp_Object num, Lisp_Object den, bool modulo)
 DEFUN ("%", Frem, Srem, 2, 2, 0,
        doc: /* Return remainder of X divided by Y.
 Both must be integers or markers.  */)
-  (register Lisp_Object x, Lisp_Object y)
+  (Lisp_Object x, Lisp_Object y)
 {
-  CHECK_INTEGER_COERCE_MARKER (x);
-  CHECK_INTEGER_COERCE_MARKER (y);
+  x = check_integer_coerce_marker (x);
+  y = check_integer_coerce_marker (y);
   return integer_remainder (x, y, false);
 }
 
@@ -3065,8 +3075,8 @@ The result falls between zero (inclusive) and Y (exclusive).
 Both X and Y must be numbers or markers.  */)
   (Lisp_Object x, Lisp_Object y)
 {
-  CHECK_NUMBER_COERCE_MARKER (x);
-  CHECK_NUMBER_COERCE_MARKER (y);
+  x = check_number_coerce_marker (x);
+  y = check_number_coerce_marker (y);
   if (FLOATP (x) || FLOATP (y))
     return fmod_float (x, y);
   return integer_remainder (x, y, true);
@@ -3076,12 +3086,10 @@ static Lisp_Object
 minmax_driver (ptrdiff_t nargs, Lisp_Object *args,
 	       enum Arith_Comparison comparison)
 {
-  Lisp_Object accum = args[0];
-  CHECK_NUMBER_COERCE_MARKER (accum);
+  Lisp_Object accum = check_number_coerce_marker (args[0]);
   for (ptrdiff_t argnum = 1; argnum < nargs; argnum++)
     {
-      Lisp_Object val = args[argnum];
-      CHECK_NUMBER_COERCE_MARKER (val);
+      Lisp_Object val = check_number_coerce_marker (args[argnum]);
       if (!NILP (arithcompare (val, accum, comparison)))
 	accum = val;
       else if (FLOATP (val) && isnan (XFLOAT_DATA (val)))
@@ -3116,8 +3124,7 @@ usage: (logand &rest INTS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (-1);
-  Lisp_Object a = args[0];
-  CHECK_INTEGER_COERCE_MARKER (a);
+  Lisp_Object a = check_integer_coerce_marker (args[0]);
   return nargs == 1 ? a : arith_driver (Alogand, nargs, args, a);
 }
 
@@ -3129,8 +3136,7 @@ usage: (logior &rest INTS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (0);
-  Lisp_Object a = args[0];
-  CHECK_INTEGER_COERCE_MARKER (a);
+  Lisp_Object a = check_integer_coerce_marker (args[0]);
   return nargs == 1 ? a : arith_driver (Alogior, nargs, args, a);
 }
 
@@ -3142,8 +3148,7 @@ usage: (logxor &rest INTS-OR-MARKERS)  */)
 {
   if (nargs == 0)
     return make_fixnum (0);
-  Lisp_Object a = args[0];
-  CHECK_INTEGER_COERCE_MARKER (a);
+  Lisp_Object a = check_integer_coerce_marker (args[0]);
   return nargs == 1 ? a : arith_driver (Alogxor, nargs, args, a);
 }
 
@@ -3262,9 +3267,9 @@ expt_integer (Lisp_Object x, Lisp_Object y)
 DEFUN ("1+", Fadd1, Sadd1, 1, 1, 0,
        doc: /* Return NUMBER plus one.  NUMBER may be a number or a marker.
 Markers are converted to integers.  */)
-  (register Lisp_Object number)
+  (Lisp_Object number)
 {
-  CHECK_NUMBER_COERCE_MARKER (number);
+  number = check_number_coerce_marker (number);
 
   if (FIXNUMP (number))
     return make_int (XFIXNUM (number) + 1);
@@ -3277,9 +3282,9 @@ Markers are converted to integers.  */)
 DEFUN ("1-", Fsub1, Ssub1, 1, 1, 0,
        doc: /* Return NUMBER minus one.  NUMBER may be a number or a marker.
 Markers are converted to integers.  */)
-  (register Lisp_Object number)
+  (Lisp_Object number)
 {
-  CHECK_NUMBER_COERCE_MARKER (number);
+  number = check_number_coerce_marker (number);
 
   if (FIXNUMP (number))
     return make_int (XFIXNUM (number) - 1);
diff --git a/src/editfns.c b/src/editfns.c
index eb15566fb48..90520d0dced 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -725,18 +725,23 @@ boundaries, bind `inhibit-field-text-motion' to t.
 This function does not move point.  */)
   (Lisp_Object n)
 {
-  ptrdiff_t charpos, bytepos;
+  ptrdiff_t charpos, bytepos, count;
 
   if (NILP (n))
-    XSETFASTINT (n, 1);
+    count = 0;
+  else if (FIXNUMP (n))
+    count = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n) - 1, BUF_BYTES_MAX);
   else
-    CHECK_FIXNUM (n);
+    {
+      CHECK_INTEGER (n);
+      count = NILP (Fnatnump (n)) ? -BUF_BYTES_MAX : BUF_BYTES_MAX;
+    }
 
-  scan_newline_from_point (XFIXNUM (n) - 1, &charpos, &bytepos);
+  scan_newline_from_point (count, &charpos, &bytepos);
 
   /* Return END constrained to the current input field.  */
   return Fconstrain_to_field (make_fixnum (charpos), make_fixnum (PT),
-			      XFIXNUM (n) != 1 ? Qt : Qnil,
+			      count != 0 ? Qt : Qnil,
 			      Qt, Qnil);
 }
 
@@ -763,11 +768,14 @@ This function does not move point.  */)
   ptrdiff_t orig = PT;
 
   if (NILP (n))
-    XSETFASTINT (n, 1);
+    clipped_n = 1;
+  else if (FIXNUMP (n))
+    clipped_n = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n), BUF_BYTES_MAX);
   else
-    CHECK_FIXNUM (n);
-
-  clipped_n = clip_to_bounds (PTRDIFF_MIN + 1, XFIXNUM (n), PTRDIFF_MAX);
+    {
+      CHECK_INTEGER (n);
+      clipped_n = NILP (Fnatnump (n)) ? -BUF_BYTES_MAX : BUF_BYTES_MAX;
+    }
   end_pos = find_before_next_newline (orig, 0, clipped_n - (clipped_n <= 0),
 				      NULL);
 
@@ -940,10 +948,10 @@ DEFUN ("position-bytes", Fposition_bytes, Sposition_bytes, 1, 1, 0,
 If POSITION is out of range, the value is nil.  */)
   (Lisp_Object position)
 {
-  CHECK_FIXNUM_COERCE_MARKER (position);
-  if (XFIXNUM (position) < BEG || XFIXNUM (position) > Z)
+  EMACS_INT pos = fix_position (position);
+  if (! (BEG <= pos && pos <= Z))
     return Qnil;
-  return make_fixnum (CHAR_TO_BYTE (XFIXNUM (position)));
+  return make_fixnum (CHAR_TO_BYTE (pos));
 }
 
 DEFUN ("byte-to-position", Fbyte_to_position, Sbyte_to_position, 1, 1, 0,
@@ -1060,11 +1068,11 @@ If POS is out of range, the value is nil.  */)
     }
   else
     {
-      CHECK_FIXNUM_COERCE_MARKER (pos);
-      if (XFIXNUM (pos) < BEGV || XFIXNUM (pos) >= ZV)
+      EMACS_INT p = fix_position (pos);
+      if (! (BEGV <= p && p < ZV))
 	return Qnil;
 
-      pos_byte = CHAR_TO_BYTE (XFIXNUM (pos));
+      pos_byte = CHAR_TO_BYTE (p);
     }
 
   return make_fixnum (FETCH_CHAR (pos_byte));
@@ -1094,12 +1102,12 @@ If POS is out of range, the value is nil.  */)
     }
   else
     {
-      CHECK_FIXNUM_COERCE_MARKER (pos);
+      EMACS_INT p = fix_position (pos);
 
-      if (XFIXNUM (pos) <= BEGV || XFIXNUM (pos) > ZV)
+      if (! (BEGV < p && p <= ZV))
 	return Qnil;
 
-      pos_byte = CHAR_TO_BYTE (XFIXNUM (pos));
+      pos_byte = CHAR_TO_BYTE (p);
     }
 
   if (!NILP (BVAR (current_buffer, enable_multibyte_characters)))
@@ -1718,21 +1726,8 @@ using `string-make-multibyte' or `string-make-unibyte', which see.  */)
   if (!BUFFER_LIVE_P (bp))
     error ("Selecting deleted buffer");
 
-  if (NILP (start))
-    b = BUF_BEGV (bp);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (start);
-      b = XFIXNUM (start);
-    }
-  if (NILP (end))
-    e = BUF_ZV (bp);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (end);
-      e = XFIXNUM (end);
-    }
-
+  b = !NILP (start) ? fix_position (start) : BUF_BEGV (bp);
+  e = !NILP (end) ? fix_position (end) : BUF_ZV (bp);
   if (b > e)
     temp = b, b = e, e = temp;
 
@@ -1786,21 +1781,8 @@ determines whether case is significant or ignored.  */)
 	error ("Selecting deleted buffer");
     }
 
-  if (NILP (start1))
-    begp1 = BUF_BEGV (bp1);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (start1);
-      begp1 = XFIXNUM (start1);
-    }
-  if (NILP (end1))
-    endp1 = BUF_ZV (bp1);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (end1);
-      endp1 = XFIXNUM (end1);
-    }
-
+  begp1 = !NILP (start1) ? fix_position (start1) : BUF_BEGV (bp1);
+  endp1 = !NILP (end1) ? fix_position (end1) : BUF_ZV (bp1);
   if (begp1 > endp1)
     temp = begp1, begp1 = endp1, endp1 = temp;
 
@@ -1824,21 +1806,8 @@ determines whether case is significant or ignored.  */)
 	error ("Selecting deleted buffer");
     }
 
-  if (NILP (start2))
-    begp2 = BUF_BEGV (bp2);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (start2);
-      begp2 = XFIXNUM (start2);
-    }
-  if (NILP (end2))
-    endp2 = BUF_ZV (bp2);
-  else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (end2);
-      endp2 = XFIXNUM (end2);
-    }
-
+  begp2 = !NILP (start2) ? fix_position (start2) : BUF_BEGV (bp2);
+  endp2 = !NILP (end2) ? fix_position (end2) : BUF_ZV (bp2);
   if (begp2 > endp2)
     temp = begp2, begp2 = endp2, endp2 = temp;
 
@@ -2692,29 +2661,27 @@ See also `save-restriction'.
 When calling from Lisp, pass two arguments START and END:
 positions (integers or markers) bounding the text that should
 remain visible.  */)
-  (register Lisp_Object start, Lisp_Object end)
+  (Lisp_Object start, Lisp_Object end)
 {
-  CHECK_FIXNUM_COERCE_MARKER (start);
-  CHECK_FIXNUM_COERCE_MARKER (end);
+  EMACS_INT s = fix_position (start), e = fix_position (end);
 
-  if (XFIXNUM (start) > XFIXNUM (end))
+  if (e < s)
     {
-      Lisp_Object tem;
-      tem = start; start = end; end = tem;
+      EMACS_INT tem = s; s = e; e = tem;
     }
 
-  if (!(BEG <= XFIXNUM (start) && XFIXNUM (start) <= XFIXNUM (end) && XFIXNUM (end) <= Z))
+  if (!(BEG <= s && s <= e && e <= Z))
     args_out_of_range (start, end);
 
-  if (BEGV != XFIXNAT (start) || ZV != XFIXNAT (end))
+  if (BEGV != s || ZV != e)
     current_buffer->clip_changed = 1;
 
-  SET_BUF_BEGV (current_buffer, XFIXNAT (start));
-  SET_BUF_ZV (current_buffer, XFIXNAT (end));
-  if (PT < XFIXNAT (start))
-    SET_PT (XFIXNAT (start));
-  if (PT > XFIXNAT (end))
-    SET_PT (XFIXNAT (end));
+  SET_BUF_BEGV (current_buffer, s);
+  SET_BUF_ZV (current_buffer, e);
+  if (PT < s)
+    SET_PT (s);
+  if (e < PT)
+    SET_PT (e);
   /* Changing the buffer bounds invalidates any recorded current column.  */
   invalidate_current_column ();
   return Qnil;
diff --git a/src/emacs-module.c b/src/emacs-module.c
index 60f16418efa..cdcbe061b53 100644
--- a/src/emacs-module.c
+++ b/src/emacs-module.c
@@ -88,6 +88,7 @@ To add a new module function, proceed as follows:
 #include "dynlib.h"
 #include "coding.h"
 #include "keyboard.h"
+#include "process.h"
 #include "syssignal.h"
 #include "sysstdio.h"
 #include "thread.h"
@@ -977,6 +978,13 @@ module_make_big_integer (emacs_env *env, int sign,
   return lisp_to_value (env, make_integer_mpz ());
 }
 
+static int
+module_open_channel (emacs_env *env, emacs_value pipe_process)
+{
+  MODULE_FUNCTION_BEGIN (-1);
+  return open_channel_for_module (value_to_lisp (pipe_process));
+}
+
 
 /* Subroutines.  */
 
@@ -1391,6 +1399,7 @@ initialize_environment (emacs_env *env, struct emacs_env_private *priv)
   env->make_big_integer = module_make_big_integer;
   env->get_function_finalizer = module_get_function_finalizer;
   env->set_function_finalizer = module_set_function_finalizer;
+  env->open_channel = module_open_channel;
   Vmodule_environments = Fcons (make_mint_ptr (env), Vmodule_environments);
   return env;
 }
diff --git a/src/fileio.c b/src/fileio.c
index ffe79559a3f..978a373d39b 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -96,7 +96,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <acl.h>
 #include <allocator.h>
 #include <careadlinkat.h>
-#include <dosname.h>
+#include <filename.h>
 #include <fsusage.h>
 #include <stat-time.h>
 #include <tempname.h>
diff --git a/src/filelock.c b/src/filelock.c
index 2b734ee00d5..ee46e0e3e00 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -661,7 +661,7 @@ void
 lock_file (Lisp_Object fn)
 {
   Lisp_Object orig_fn, encoded_fn;
-  char *lfname;
+  char *lfname = NULL;
   lock_info_type lock_info;
   USE_SAFE_ALLOCA;
 
@@ -686,21 +686,15 @@ lock_file (Lisp_Object fn)
 
   /* See if this file is visited and has changed on disk since it was
      visited.  */
-  {
-    register Lisp_Object subject_buf;
-
-    subject_buf = get_truename_buffer (orig_fn);
-
-    if (!NILP (subject_buf)
-	&& NILP (Fverify_visited_file_modtime (subject_buf))
-        && !NILP (Ffile_exists_p (fn))
-        && (!create_lockfiles || current_lock_owner (NULL, lfname) != -2))
-      call1 (intern ("userlock--ask-user-about-supersession-threat"), fn);
-
-  }
+  Lisp_Object subject_buf = get_truename_buffer (orig_fn);
+  if (!NILP (subject_buf)
+      && NILP (Fverify_visited_file_modtime (subject_buf))
+      && !NILP (Ffile_exists_p (fn))
+      && !(lfname && current_lock_owner (NULL, lfname) == -2))
+    call1 (intern ("userlock--ask-user-about-supersession-threat"), fn);
 
   /* Don't do locking if the user has opted out.  */
-  if (create_lockfiles)
+  if (lfname)
     {
       /* Try to lock the lock.  FIXME: This ignores errors when
 	 lock_if_free returns a positive errno value.  */
@@ -860,7 +854,7 @@ syms_of_filelock (void)
 The name of the (per-buffer) lockfile is constructed by prepending a
 '.#' to the name of the file being locked.  See also `lock-buffer' and
 Info node `(emacs)Interlocking'.  */);
-  create_lockfiles = 1;
+  create_lockfiles = true;
 
   defsubr (&Sunlock_buffer);
   defsubr (&Slock_buffer);
diff --git a/src/fns.c b/src/fns.c
index 80012fa9d28..138082e07c8 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -5187,22 +5187,8 @@ extract_data_from_object (Lisp_Object spec,
       struct buffer *bp = XBUFFER (object);
       set_buffer_internal (bp);
 
-      if (NILP (start))
-	b = BEGV;
-      else
-	{
-	  CHECK_FIXNUM_COERCE_MARKER (start);
-	  b = XFIXNUM (start);
-	}
-
-      if (NILP (end))
-	e = ZV;
-      else
-	{
-	  CHECK_FIXNUM_COERCE_MARKER (end);
-	  e = XFIXNUM (end);
-	}
-
+      b = !NILP (start) ? fix_position (start) : BEGV;
+      e = !NILP (end) ? fix_position (end) : ZV;
       if (b > e)
 	{
 	  EMACS_INT temp = b;
diff --git a/src/font.c b/src/font.c
index 2a456300619..0c9e752e089 100644
--- a/src/font.c
+++ b/src/font.c
@@ -4606,10 +4606,10 @@ DEFUN ("internal-char-font", Finternal_char_font, Sinternal_char_font, 1, 2, 0,
       Lisp_Object window;
       struct window *w;
 
-      CHECK_FIXNUM_COERCE_MARKER (position);
-      if (! (BEGV <= XFIXNUM (position) && XFIXNUM (position) < ZV))
+      EMACS_INT fixed_pos = fix_position (position);
+      if (! (BEGV <= fixed_pos && fixed_pos < ZV))
 	args_out_of_range_3 (position, make_fixnum (BEGV), make_fixnum (ZV));
-      pos = XFIXNUM (position);
+      pos = fixed_pos;
       pos_byte = CHAR_TO_BYTE (pos);
       if (NILP (ch))
 	c = FETCH_CHAR (pos_byte);
@@ -5013,24 +5013,26 @@ character at index specified by POSITION.  */)
   (Lisp_Object position, Lisp_Object window, Lisp_Object string)
 {
   struct window *w = decode_live_window (window);
+  EMACS_INT pos;
 
   if (NILP (string))
     {
       if (XBUFFER (w->contents) != current_buffer)
 	error ("Specified window is not displaying the current buffer");
-      CHECK_FIXNUM_COERCE_MARKER (position);
-      if (! (BEGV <= XFIXNUM (position) && XFIXNUM (position) < ZV))
+      pos = fix_position (position);
+      if (! (BEGV <= pos && pos < ZV))
 	args_out_of_range_3 (position, make_fixnum (BEGV), make_fixnum (ZV));
     }
   else
     {
       CHECK_FIXNUM (position);
       CHECK_STRING (string);
-      if (! (0 <= XFIXNUM (position) && XFIXNUM (position) < SCHARS (string)))
+      pos = XFIXNUM (position);
+      if (! (0 <= pos && pos < SCHARS (string)))
 	args_out_of_range (string, position);
     }
 
-  return font_at (-1, XFIXNUM (position), NULL, w, string);
+  return font_at (-1, pos, NULL, w, string);
 }
 
 #if 0
diff --git a/src/fringe.c b/src/fringe.c
index 2a46e3c34f2..d8d80bb3fe9 100644
--- a/src/fringe.c
+++ b/src/fringe.c
@@ -1675,10 +1675,10 @@ Return nil if POS is not visible in WINDOW.  */)
 
   if (!NILP (pos))
     {
-      CHECK_FIXNUM_COERCE_MARKER (pos);
-      if (! (BEGV <= XFIXNUM (pos) && XFIXNUM (pos) <= ZV))
+      EMACS_INT p = fix_position (pos);
+      if (! (BEGV <= p && p <= ZV))
 	args_out_of_range (window, pos);
-      textpos = XFIXNUM (pos);
+      textpos = p;
     }
   else if (w == XWINDOW (selected_window))
     textpos = PT;
diff --git a/src/lisp.h b/src/lisp.h
index f86b4880f35..2f719b1f03e 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -585,7 +585,7 @@ INLINE void set_sub_char_table_contents (Lisp_Object, ptrdiff_t,
 					      Lisp_Object);
 
 /* Defined in bignum.c.  */
-extern double bignum_to_double (Lisp_Object);
+extern double bignum_to_double (Lisp_Object) ATTRIBUTE_CONST;
 extern Lisp_Object make_bigint (intmax_t);
 extern Lisp_Object make_biguint (uintmax_t);
 
@@ -3023,14 +3023,6 @@ CHECK_FIXNAT (Lisp_Object x)
       CHECK_RANGED_INTEGER (x, 0, TYPE_MAXIMUM (type));			\
   } while (false)
 
-#define CHECK_FIXNUM_COERCE_MARKER(x)					\
-  do {									\
-    if (MARKERP ((x)))							\
-      XSETFASTINT (x, marker_position (x));				\
-    else								\
-      CHECK_TYPE (FIXNUMP (x), Qinteger_or_marker_p, x);		\
-  } while (false)
-
 INLINE double
 XFLOATINT (Lisp_Object n)
 {
@@ -3050,22 +3042,6 @@ CHECK_INTEGER (Lisp_Object x)
 {
   CHECK_TYPE (INTEGERP (x), Qnumberp, x);
 }
-
-#define CHECK_NUMBER_COERCE_MARKER(x)					\
-  do {									\
-    if (MARKERP (x))							\
-      XSETFASTINT (x, marker_position (x));				\
-    else								\
-      CHECK_TYPE (NUMBERP (x), Qnumber_or_marker_p, x);			\
-  } while (false)
-
-#define CHECK_INTEGER_COERCE_MARKER(x)					\
-  do {									\
-    if (MARKERP (x))							\
-      XSETFASTINT (x, marker_position (x));				\
-    else								\
-      CHECK_TYPE (INTEGERP (x), Qnumber_or_marker_p, x);		\
-  } while (false)
 
 
 /* If we're not dumping using the legacy dumper and we might be using
@@ -3519,9 +3495,9 @@ set_sub_char_table_contents (Lisp_Object table, ptrdiff_t idx, Lisp_Object val)
 
 /* Defined in bignum.c.  This part of bignum.c's API does not require
    the caller to access bignum internals; see bignum.h for that.  */
-extern intmax_t bignum_to_intmax (Lisp_Object);
-extern uintmax_t bignum_to_uintmax (Lisp_Object);
-extern ptrdiff_t bignum_bufsize (Lisp_Object, int);
+extern intmax_t bignum_to_intmax (Lisp_Object) ATTRIBUTE_CONST;
+extern uintmax_t bignum_to_uintmax (Lisp_Object) ATTRIBUTE_CONST;
+extern ptrdiff_t bignum_bufsize (Lisp_Object, int) ATTRIBUTE_CONST;
 extern ptrdiff_t bignum_to_c_string (char *, ptrdiff_t, Lisp_Object, int);
 extern Lisp_Object bignum_to_string (Lisp_Object, int);
 extern Lisp_Object make_bignum_str (char const *, int);
diff --git a/src/module-env-28.h b/src/module-env-28.h
index a2479a8f744..5d884c148c4 100644
--- a/src/module-env-28.h
+++ b/src/module-env-28.h
@@ -9,3 +9,6 @@
   void (*set_function_finalizer) (emacs_env *env, emacs_value arg,
                                   void (*fin) (void *) EMACS_NOEXCEPT)
     EMACS_ATTRIBUTE_NONNULL (1);
+
+  int (*open_channel) (emacs_env *env, emacs_value pipe_process)
+    EMACS_ATTRIBUTE_NONNULL (1);
diff --git a/src/process.c b/src/process.c
index e4e5e57aeee..07881d6c5d3 100644
--- a/src/process.c
+++ b/src/process.c
@@ -8200,6 +8200,17 @@ restore_nofile_limit (void)
 #endif
 }
 
+int
+open_channel_for_module (Lisp_Object process)
+{
+  CHECK_PROCESS (process);
+  CHECK_TYPE (PIPECONN_P (process), Qpipe_process_p, process);
+  int fd = dup (XPROCESS (process)->open_fd[SUBPROCESS_STDOUT]);
+  if (fd == -1)
+    report_file_error ("Cannot duplicate file descriptor", Qnil);
+  return fd;
+}
+
 
 /* This is not called "init_process" because that is the name of a
    Mach system call, so it would cause problems on Darwin systems.  */
@@ -8446,6 +8457,7 @@ amounts of data in one go.  */);
   DEFSYM (Qinterrupt_process_functions, "interrupt-process-functions");
 
   DEFSYM (Qnull, "null");
+  DEFSYM (Qpipe_process_p, "pipe-process-p");
 
   defsubr (&Sprocessp);
   defsubr (&Sget_process);
diff --git a/src/process.h b/src/process.h
index 7884efc5494..a783a31cb86 100644
--- a/src/process.h
+++ b/src/process.h
@@ -300,6 +300,8 @@ extern Lisp_Object remove_slash_colon (Lisp_Object);
 extern void update_processes_for_thread_death (Lisp_Object);
 extern void dissociate_controlling_tty (void);
 
+extern int open_channel_for_module (Lisp_Object);
+
 INLINE_HEADER_END
 
 #endif /* EMACS_PROCESS_H */
diff --git a/src/search.c b/src/search.c
index 818bb4af246..7389fbef0ee 100644
--- a/src/search.c
+++ b/src/search.c
@@ -1028,8 +1028,7 @@ search_command (Lisp_Object string, Lisp_Object bound, Lisp_Object noerror,
     }
   else
     {
-      CHECK_FIXNUM_COERCE_MARKER (bound);
-      lim = XFIXNUM (bound);
+      lim = fix_position (bound);
       if (n > 0 ? lim < PT : lim > PT)
 	error ("Invalid search bound (wrong side of point)");
       if (lim > ZV)
diff --git a/src/textprop.c b/src/textprop.c
index ee048336ac0..960dba3f8dc 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -131,6 +131,7 @@ validate_interval_range (Lisp_Object object, Lisp_Object *begin,
 {
   INTERVAL i;
   ptrdiff_t searchpos;
+  Lisp_Object begin0 = *begin, end0 = *end;
 
   CHECK_STRING_OR_BUFFER (object);
   CHECK_FIXNUM_COERCE_MARKER (*begin);
@@ -155,7 +156,7 @@ validate_interval_range (Lisp_Object object, Lisp_Object *begin,
 
       if (!(BUF_BEGV (b) <= XFIXNUM (*begin) && XFIXNUM (*begin) <= XFIXNUM (*end)
 	    && XFIXNUM (*end) <= BUF_ZV (b)))
-	args_out_of_range (*begin, *end);
+	args_out_of_range (begin0, end0);
       i = buffer_intervals (b);
 
       /* If there's no text, there are no properties.  */
@@ -170,7 +171,7 @@ validate_interval_range (Lisp_Object object, Lisp_Object *begin,
 
       if (! (0 <= XFIXNUM (*begin) && XFIXNUM (*begin) <= XFIXNUM (*end)
 	     && XFIXNUM (*end) <= len))
-	args_out_of_range (*begin, *end);
+	args_out_of_range (begin0, end0);
       i = string_intervals (object);
 
       if (len == 0)
@@ -611,7 +612,7 @@ get_char_property_and_overlay (Lisp_Object position, register Lisp_Object prop,
 {
   struct window *w = 0;
 
-  CHECK_FIXNUM_COERCE_MARKER (position);
+  EMACS_INT pos = fix_position (position);
 
   if (NILP (object))
     XSETBUFFER (object, current_buffer);
@@ -628,14 +629,14 @@ get_char_property_and_overlay (Lisp_Object position, register Lisp_Object prop,
       Lisp_Object *overlay_vec;
       struct buffer *obuf = current_buffer;
 
-      if (XFIXNUM (position) < BUF_BEGV (XBUFFER (object))
-	  || XFIXNUM (position) > BUF_ZV (XBUFFER (object)))
+      if (! (BUF_BEGV (XBUFFER (object)) <= pos
+	     && pos <= BUF_ZV (XBUFFER (object))))
 	xsignal1 (Qargs_out_of_range, position);
 
       set_buffer_temp (XBUFFER (object));
 
       USE_SAFE_ALLOCA;
-      GET_OVERLAYS_AT (XFIXNUM (position), overlay_vec, noverlays, NULL, false);
+      GET_OVERLAYS_AT (pos, overlay_vec, noverlays, NULL, false);
       noverlays = sort_overlays (overlay_vec, noverlays, w);
 
       set_buffer_temp (obuf);
@@ -662,7 +663,7 @@ get_char_property_and_overlay (Lisp_Object position, register Lisp_Object prop,
 
   /* Not a buffer, or no appropriate overlay, so fall through to the
      simpler case.  */
-  return Fget_text_property (position, prop, object);
+  return Fget_text_property (make_fixnum (pos), prop, object);
 }
 
 DEFUN ("get-char-property", Fget_char_property, Sget_char_property, 2, 3, 0,
diff --git a/src/window.c b/src/window.c
index 8cdad27b664..075fd4e550c 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1895,10 +1895,7 @@ POS, ROWH is the visible height of that row, and VPOS is the row number
   if (EQ (pos, Qt))
     posint = -1;
   else if (!NILP (pos))
-    {
-      CHECK_FIXNUM_COERCE_MARKER (pos);
-      posint = XFIXNUM (pos);
-    }
+    posint = fix_position (pos);
   else if (w == XWINDOW (selected_window))
     posint = PT;
   else
diff --git a/src/xdisp.c b/src/xdisp.c
index 04fc8aa3c45..61c798c59e8 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -815,11 +815,6 @@ static struct props it_props[] =
   {0,				0,			NULL}
 };
 
-/* Value is the position described by X.  If X is a marker, value is
-   the marker_position of X.  Otherwise, value is X.  */
-
-#define COERCE_MARKER(X) (MARKERP ((X)) ? Fmarker_position (X) : (X))
-
 /* Enumeration returned by some move_it_.* functions internally.  */
 
 enum move_it_result
@@ -10418,10 +10413,7 @@ include the height of both, if present, in the return value.  */)
 	start = pos;
     }
   else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (from);
-      start = min (max (XFIXNUM (from), BEGV), ZV);
-    }
+    start = clip_to_bounds (BEGV, fix_position (from), ZV);
 
   if (NILP (to))
     end = ZV;
@@ -10435,10 +10427,7 @@ include the height of both, if present, in the return value.  */)
 	end = pos;
     }
   else
-    {
-      CHECK_FIXNUM_COERCE_MARKER (to);
-      end = max (start, min (XFIXNUM (to), ZV));
-    }
+    end = clip_to_bounds (start, fix_position (to), ZV);
 
   if (!NILP (x_limit) && RANGED_FIXNUMP (0, x_limit, INT_MAX))
     max_x = XFIXNUM (x_limit);
@@ -14944,7 +14933,7 @@ overlay_arrows_changed_p (bool set_redisplay)
       val = find_symbol_value (var);
       if (!MARKERP (val))
 	continue;
-      if (! EQ (COERCE_MARKER (val),
+      if (! EQ (Fmarker_position (val),
                 /* FIXME: Don't we have a problem, using such a global
                  * "last-position" if the variable is buffer-local?  */
 		Fget (var, Qlast_arrow_position))
@@ -14987,8 +14976,7 @@ update_overlay_arrows (int up_to_date)
 	  Lisp_Object val = find_symbol_value (var);
           if (!MARKERP (val))
 	    continue;
-	  Fput (var, Qlast_arrow_position,
-		COERCE_MARKER (val));
+	  Fput (var, Qlast_arrow_position, Fmarker_position (val));
 	  Fput (var, Qlast_arrow_string,
 		overlay_arrow_string_or_property (var));
 	}