[PATCH v2 07/16] Take offset not idx in PER_BUFFER_VALUE_P

[Spencer Baugh]

This also moves the common "idx == -1" check into PER_BUFFER_VALUE_P.
If idx == -1, it's guaranteed that the corresponding buffer field has
a per-buffer value.  We do this check everywhere we call
PER_BUFFER_VALUE_P, so let's put it in the common code.

This is motivated by later commits which will get rid of idx.
---
 src/buffer.c |  3 +--
 src/buffer.h | 21 +++++++++++----------
 src/data.c   | 11 +++++------
 3 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/src/buffer.c b/src/buffer.c
index aa951ca78f..a0bcbf38e5 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1297,8 +1297,7 @@ buffer_lisp_local_variables (struct buffer *buf, bool 
clone)
 static Lisp_Object
 buffer_local_variables_1 (struct buffer *buf, int offset, Lisp_Object sym)
 {
-  int idx = PER_BUFFER_IDX (offset);
-  if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
+  if (PER_BUFFER_VALUE_P (buf, offset)
       && SYMBOLP (PER_BUFFER_SYMBOL (offset)))
     {
       sym = NILP (sym) ? PER_BUFFER_SYMBOL (offset) : sym;
diff --git a/src/buffer.h b/src/buffer.h
index 770a5d03e6..69df791b53 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1420,16 +1420,6 @@ OVERLAY_POSITION (Lisp_Object p)
 
 extern bool valid_per_buffer_idx (int);
 
-/* Value is true if the variable with index IDX has a local value
-   in buffer B.  */
-
-INLINE bool
-PER_BUFFER_VALUE_P (struct buffer *b, int idx)
-{
-  eassert (valid_per_buffer_idx (idx));
-  return b->local_flags[idx];
-}
-
 /* Set whether per-buffer variable with index IDX has a buffer-local
    value in buffer B.  VAL zero means it hasn't.  */
 
@@ -1496,6 +1486,17 @@ set_per_buffer_value (struct buffer *b, int offset, 
Lisp_Object value)
   *(Lisp_Object *)(offset + (char *) b) = value;
 }
 
+/* Value is true if the variable with offset OFFSET has a local value
+   in buffer B.  */
+
+INLINE bool
+PER_BUFFER_VALUE_P (struct buffer *b, int offset)
+{
+  int idx = PER_BUFFER_IDX (offset);
+  eassert (idx == -1 || valid_per_buffer_idx (idx));
+  return idx == -1 || b->local_flags[idx];
+}
+
 /* Downcase a character C, or make no change if that cannot be done.  */
 INLINE int
 downcase (int c)
diff --git a/src/data.c b/src/data.c
index 384c259220..47a1a6640f 100644
--- a/src/data.c
+++ b/src/data.c
@@ -1123,7 +1123,7 @@ store_symval_forwarding (lispfwd valcontents, Lisp_Object 
newval,
            {
              struct buffer *b = XBUFFER (buf);
 
-             if (! PER_BUFFER_VALUE_P (b, idx))
+             if (! PER_BUFFER_VALUE_P (b, offset))
                set_per_buffer_value (b, offset, newval);
            }
        }
@@ -1440,8 +1440,8 @@ set_internal (Lisp_Object symbol, Lisp_Object newval, 
Lisp_Object where,
          {
            int offset = XBUFFER_OBJFWD (innercontents)->offset;
            int idx = PER_BUFFER_IDX (offset);
-           if (idx > 0 && bindflag == SET_INTERNAL_SET
-               && !PER_BUFFER_VALUE_P (buf, idx))
+           if (bindflag == SET_INTERNAL_SET
+               && !PER_BUFFER_VALUE_P (buf, offset))
              {
                if (let_shadows_buffer_binding_p (sym))
                  set_default_internal (symbol, newval, bindflag);
@@ -1740,7 +1740,7 @@ set_default_internal (Lisp_Object symbol, Lisp_Object 
value,
                  {
                    struct buffer *b = XBUFFER (buf);
 
-                   if (!PER_BUFFER_VALUE_P (b, idx))
+                   if (!PER_BUFFER_VALUE_P (b, offset))
                      set_per_buffer_value (b, offset, value);
                  }
              }
@@ -2077,8 +2077,7 @@ BUFFER defaults to the current buffer.  */)
        if (BUFFER_OBJFWDP (valcontents))
          {
            int offset = XBUFFER_OBJFWD (valcontents)->offset;
-           int idx = PER_BUFFER_IDX (offset);
-           if (idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
+           if (PER_BUFFER_VALUE_P (buf, offset))
              return Qt;
          }
        return Qnil;
-- 
2.28.0