Fix recently introduced crash on MS-Windows (Bug#12839).

* w32term.h (struct scroll_bar): Use convenient header.
(SCROLL_BAR_VEC_SIZE): Remove.
* w32term.c (x_scroll_bar_create): Use VECSIZE.

1 files changed, 2 insertions, 9 deletions

diff --git a/src/w32term.h b/src/w32term.h
index af5b37a1171..72fb8a76e35 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -415,9 +415,8 @@ extern struct w32_output w32term_display;
 
 struct scroll_bar {
 
-  /* These fields are shared by all vectors.  */
-  EMACS_INT size_from_Lisp_Vector_struct;
-  struct Lisp_Vector *next_from_Lisp_Vector_struct;
+  /* This field is shared by all vectors.  */
+  struct vectorlike_header header;
 
   /* The window we're a scroll bar for.  */
   Lisp_Object window;
@@ -460,12 +459,6 @@ struct scroll_bar {
   Lisp_Object fringe_extended_p;
 };
 
-/* The number of elements a vector holding a struct scroll_bar needs.  */
-#define SCROLL_BAR_VEC_SIZE                                     \
-  ((sizeof (struct scroll_bar)                                  \
-    - sizeof (EMACS_INT) - sizeof (struct Lisp_Vector *))       \
-   / word_size)
-
 /* Turning a lisp vector value into a pointer to a struct scroll_bar.  */
 #define XSCROLL_BAR(vec) ((struct scroll_bar *) XVECTOR (vec))